From 8018168cf14d46e32a9674df97a8db64730575d3 Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Wed, 17 Jan 2024 20:26:36 -0600
Subject: [PATCH 01/28] refactor(fmt): Remove glob mods

---
 src/fmt/mod.rs                     | 7 ++-----
 src/fmt/writer/buffer/plain.rs     | 2 +-
 src/fmt/writer/buffer/termcolor.rs | 2 +-
 src/fmt/writer/mod.rs              | 4 ----
 src/lib.rs                         | 2 +-
 5 files changed, 5 insertions(+), 12 deletions(-)

diff --git a/src/fmt/mod.rs b/src/fmt/mod.rs
index 5f1d5c8f..95feb782 100644
--- a/src/fmt/mod.rs
+++ b/src/fmt/mod.rs
@@ -50,14 +50,11 @@ pub use style::{Color, Style, StyledValue};
 
 #[cfg(feature = "humantime")]
 pub use self::humantime::Timestamp;
-pub use self::writer::glob::*;
+pub use self::writer::Target;
+pub use self::writer::WriteStyle;
 
 use self::writer::{Buffer, Writer};
 
-pub(crate) mod glob {
-    pub use super::{Target, TimestampPrecision, WriteStyle};
-}
-
 /// Formatting precision of timestamps.
 ///
 /// Seconds give precision of full seconds, milliseconds give thousands of a
diff --git a/src/fmt/writer/buffer/plain.rs b/src/fmt/writer/buffer/plain.rs
index e6809b06..99056783 100644
--- a/src/fmt/writer/buffer/plain.rs
+++ b/src/fmt/writer/buffer/plain.rs
@@ -1,6 +1,6 @@
 use std::{io, sync::Mutex};
 
-use crate::fmt::{WritableTarget, WriteStyle};
+use crate::fmt::writer::{WritableTarget, WriteStyle};
 
 pub(in crate::fmt::writer) struct BufferWriter {
     target: WritableTarget,
diff --git a/src/fmt/writer/buffer/termcolor.rs b/src/fmt/writer/buffer/termcolor.rs
index d3090a17..648ed16f 100644
--- a/src/fmt/writer/buffer/termcolor.rs
+++ b/src/fmt/writer/buffer/termcolor.rs
@@ -3,7 +3,7 @@ use std::sync::Mutex;
 
 use termcolor::{self, ColorSpec, WriteColor};
 
-use crate::fmt::{WritableTarget, WriteStyle};
+use crate::fmt::writer::{WritableTarget, WriteStyle};
 
 pub(in crate::fmt::writer) struct BufferWriter {
     inner: termcolor::BufferWriter,
diff --git a/src/fmt/writer/mod.rs b/src/fmt/writer/mod.rs
index 41466b92..986b75c6 100644
--- a/src/fmt/writer/mod.rs
+++ b/src/fmt/writer/mod.rs
@@ -5,10 +5,6 @@ use self::atty::{is_stderr, is_stdout};
 use self::buffer::BufferWriter;
 use std::{fmt, io, mem, sync::Mutex};
 
-pub(super) mod glob {
-    pub use super::*;
-}
-
 pub(super) use self::buffer::Buffer;
 
 /// Log target, either `stdout`, `stderr` or a custom pipe.
diff --git a/src/lib.rs b/src/lib.rs
index cdc2badc..93eba6ce 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -280,5 +280,5 @@ mod logger;
 pub mod filter;
 pub mod fmt;
 
-pub use self::fmt::glob::*;
+pub use self::fmt::{Target, TimestampPrecision, WriteStyle};
 pub use self::logger::*;

From f4808e46e8adf6f4d0182538070ce98f11723bb1 Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Wed, 17 Jan 2024 20:29:23 -0600
Subject: [PATCH 02/28] refactor(fmt): Pull out target mod

---
 src/fmt/writer/mod.rs    | 98 ++--------------------------------------
 src/fmt/writer/target.rs | 96 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 99 insertions(+), 95 deletions(-)
 create mode 100644 src/fmt/writer/target.rs

diff --git a/src/fmt/writer/mod.rs b/src/fmt/writer/mod.rs
index 986b75c6..c8753e0f 100644
--- a/src/fmt/writer/mod.rs
+++ b/src/fmt/writer/mod.rs
@@ -1,5 +1,6 @@
 mod atty;
 mod buffer;
+mod target;
 
 use self::atty::{is_stderr, is_stdout};
 use self::buffer::BufferWriter;
@@ -7,102 +8,9 @@ use std::{fmt, io, mem, sync::Mutex};
 
 pub(super) use self::buffer::Buffer;
 
-/// Log target, either `stdout`, `stderr` or a custom pipe.
-#[non_exhaustive]
-pub enum Target {
-    /// Logs will be sent to standard output.
-    Stdout,
-    /// Logs will be sent to standard error.
-    Stderr,
-    /// Logs will be sent to a custom pipe.
-    Pipe(Box<dyn io::Write + Send + 'static>),
-}
-
-impl Default for Target {
-    fn default() -> Self {
-        Target::Stderr
-    }
-}
-
-impl fmt::Debug for Target {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(
-            f,
-            "{}",
-            match self {
-                Self::Stdout => "stdout",
-                Self::Stderr => "stderr",
-                Self::Pipe(_) => "pipe",
-            }
-        )
-    }
-}
-
-/// Log target, either `stdout`, `stderr` or a custom pipe.
-///
-/// Same as `Target`, except the pipe is wrapped in a mutex for interior mutability.
-pub(super) enum WritableTarget {
-    /// Logs will be written to standard output.
-    #[allow(dead_code)]
-    WriteStdout,
-    /// Logs will be printed to standard output.
-    PrintStdout,
-    /// Logs will be written to standard error.
-    #[allow(dead_code)]
-    WriteStderr,
-    /// Logs will be printed to standard error.
-    PrintStderr,
-    /// Logs will be sent to a custom pipe.
-    Pipe(Box<Mutex<dyn io::Write + Send + 'static>>),
-}
-
-impl WritableTarget {
-    fn print(&self, buf: &Buffer) -> io::Result<()> {
-        use std::io::Write as _;
+pub use target::Target;
+use target::WritableTarget;
 
-        let buf = buf.as_bytes();
-        match self {
-            WritableTarget::WriteStdout => {
-                let stream = std::io::stdout();
-                let mut stream = stream.lock();
-                stream.write_all(buf)?;
-                stream.flush()?;
-            }
-            WritableTarget::PrintStdout => print!("{}", String::from_utf8_lossy(buf)),
-            WritableTarget::WriteStderr => {
-                let stream = std::io::stderr();
-                let mut stream = stream.lock();
-                stream.write_all(buf)?;
-                stream.flush()?;
-            }
-            WritableTarget::PrintStderr => eprint!("{}", String::from_utf8_lossy(buf)),
-            // Safety: If the target type is `Pipe`, `target_pipe` will always be non-empty.
-            WritableTarget::Pipe(pipe) => {
-                let mut stream = pipe.lock().unwrap();
-                stream.write_all(buf)?;
-                stream.flush()?;
-            }
-        }
-
-        Ok(())
-    }
-}
-
-impl fmt::Debug for WritableTarget {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(
-            f,
-            "{}",
-            match self {
-                Self::WriteStdout => "stdout",
-                Self::PrintStdout => "stdout",
-                Self::WriteStderr => "stderr",
-                Self::PrintStderr => "stderr",
-                Self::Pipe(_) => "pipe",
-            }
-        )
-    }
-}
 /// Whether or not to print styles to the target.
 #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
 pub enum WriteStyle {
diff --git a/src/fmt/writer/target.rs b/src/fmt/writer/target.rs
new file mode 100644
index 00000000..3d908665
--- /dev/null
+++ b/src/fmt/writer/target.rs
@@ -0,0 +1,96 @@
+/// Log target, either `stdout`, `stderr` or a custom pipe.
+#[non_exhaustive]
+pub enum Target {
+    /// Logs will be sent to standard output.
+    Stdout,
+    /// Logs will be sent to standard error.
+    Stderr,
+    /// Logs will be sent to a custom pipe.
+    Pipe(Box<dyn std::io::Write + Send + 'static>),
+}
+
+impl Default for Target {
+    fn default() -> Self {
+        Target::Stderr
+    }
+}
+
+impl std::fmt::Debug for Target {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            "{}",
+            match self {
+                Self::Stdout => "stdout",
+                Self::Stderr => "stderr",
+                Self::Pipe(_) => "pipe",
+            }
+        )
+    }
+}
+
+/// Log target, either `stdout`, `stderr` or a custom pipe.
+///
+/// Same as `Target`, except the pipe is wrapped in a mutex for interior mutability.
+pub(super) enum WritableTarget {
+    /// Logs will be written to standard output.
+    #[allow(dead_code)]
+    WriteStdout,
+    /// Logs will be printed to standard output.
+    PrintStdout,
+    /// Logs will be written to standard error.
+    #[allow(dead_code)]
+    WriteStderr,
+    /// Logs will be printed to standard error.
+    PrintStderr,
+    /// Logs will be sent to a custom pipe.
+    Pipe(Box<std::sync::Mutex<dyn std::io::Write + Send + 'static>>),
+}
+
+impl WritableTarget {
+    pub(super) fn print(&self, buf: &super::Buffer) -> std::io::Result<()> {
+        use std::io::Write as _;
+
+        let buf = buf.as_bytes();
+        match self {
+            WritableTarget::WriteStdout => {
+                let stream = std::io::stdout();
+                let mut stream = stream.lock();
+                stream.write_all(buf)?;
+                stream.flush()?;
+            }
+            WritableTarget::PrintStdout => print!("{}", String::from_utf8_lossy(buf)),
+            WritableTarget::WriteStderr => {
+                let stream = std::io::stderr();
+                let mut stream = stream.lock();
+                stream.write_all(buf)?;
+                stream.flush()?;
+            }
+            WritableTarget::PrintStderr => eprint!("{}", String::from_utf8_lossy(buf)),
+            // Safety: If the target type is `Pipe`, `target_pipe` will always be non-empty.
+            WritableTarget::Pipe(pipe) => {
+                let mut stream = pipe.lock().unwrap();
+                stream.write_all(buf)?;
+                stream.flush()?;
+            }
+        }
+
+        Ok(())
+    }
+}
+
+impl std::fmt::Debug for WritableTarget {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            "{}",
+            match self {
+                Self::WriteStdout => "stdout",
+                Self::PrintStdout => "stdout",
+                Self::WriteStderr => "stderr",
+                Self::PrintStderr => "stderr",
+                Self::Pipe(_) => "pipe",
+            }
+        )
+    }
+}

From a77a76138dc28723d07ad8816b5f524d71778bd0 Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Tue, 16 Jan 2024 14:35:21 -0600
Subject: [PATCH 03/28] chore: Bump MSRV to 1.71

- 1.70.0 is needed for `anstream` to be added
- 1.71.0 is needed for changes to how cargo treats features
---
 .clippy.toml             | 2 +-
 .github/workflows/ci.yml | 6 +++---
 Cargo.toml               | 2 +-
 src/fmt/writer/mod.rs    | 8 +++-----
 src/fmt/writer/target.rs | 8 +++-----
 5 files changed, 11 insertions(+), 15 deletions(-)

diff --git a/.clippy.toml b/.clippy.toml
index 146c2e97..18554b15 100644
--- a/.clippy.toml
+++ b/.clippy.toml
@@ -1,4 +1,4 @@
-msrv = "1.60.0"  # MSRV
+msrv = "1.71"  # MSRV
 warn-on-all-wildcard-imports = true
 disallowed-methods = [
     { path = "std::option::Option::map_or", reason = "prefer `map(..).unwrap_or(..)` for legibility" },
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index de41ed3a..49e64dfc 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -48,7 +48,7 @@ jobs:
     - name: Run crate example
       run: cargo run --example default
   msrv:
-    name: "Check MSRV: 1.60.0"
+    name: "Check MSRV: 1.71"
     runs-on: ubuntu-latest
     steps:
     - name: Checkout repository
@@ -56,7 +56,7 @@ jobs:
     - name: Install Rust
       uses: dtolnay/rust-toolchain@stable
       with:
-        toolchain: "1.60"  # MSRV
+        toolchain: "1.71"  # MSRV
     - uses: Swatinem/rust-cache@v2
     - uses: taiki-e/install-action@cargo-hack
     - name: Check
@@ -115,7 +115,7 @@ jobs:
     - name: Install Rust
       uses: dtolnay/rust-toolchain@stable
       with:
-        toolchain: "1.60"  # MSRV
+        toolchain: "1.71"  # MSRV
         components: clippy
     - uses: Swatinem/rust-cache@v2
     - name: Install SARIF tools
diff --git a/Cargo.toml b/Cargo.toml
index 08da79ce..3d19de74 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -10,7 +10,7 @@ categories = ["development-tools::debugging"]
 keywords = ["logging", "log", "logger"]
 license = "MIT OR Apache-2.0"
 edition = "2021"
-rust-version = "1.60.0"  # MSRV
+rust-version = "1.71"  # MSRV
 include = [
   "build.rs",
   "src/**/*",
diff --git a/src/fmt/writer/mod.rs b/src/fmt/writer/mod.rs
index c8753e0f..4195e788 100644
--- a/src/fmt/writer/mod.rs
+++ b/src/fmt/writer/mod.rs
@@ -13,8 +13,10 @@ use target::WritableTarget;
 
 /// Whether or not to print styles to the target.
 #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
+#[derive(Default)]
 pub enum WriteStyle {
     /// Try to print styles, but don't force the issue.
+    #[default]
     Auto,
     /// Try very hard to print styles.
     Always,
@@ -22,11 +24,7 @@ pub enum WriteStyle {
     Never,
 }
 
-impl Default for WriteStyle {
-    fn default() -> Self {
-        WriteStyle::Auto
-    }
-}
+
 
 #[cfg(feature = "color")]
 impl WriteStyle {
diff --git a/src/fmt/writer/target.rs b/src/fmt/writer/target.rs
index 3d908665..c3fe4825 100644
--- a/src/fmt/writer/target.rs
+++ b/src/fmt/writer/target.rs
@@ -1,19 +1,17 @@
 /// Log target, either `stdout`, `stderr` or a custom pipe.
 #[non_exhaustive]
+#[derive(Default)]
 pub enum Target {
     /// Logs will be sent to standard output.
     Stdout,
     /// Logs will be sent to standard error.
+    #[default]
     Stderr,
     /// Logs will be sent to a custom pipe.
     Pipe(Box<dyn std::io::Write + Send + 'static>),
 }
 
-impl Default for Target {
-    fn default() -> Self {
-        Target::Stderr
-    }
-}
+
 
 impl std::fmt::Debug for Target {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {

From fb603ba2e711b743398ba54c263396d797ead2c0 Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Tue, 16 Jan 2024 14:36:37 -0600
Subject: [PATCH 04/28] perf: Remove is-terminal dependency

Fixes #276
---
 Cargo.lock             | 148 -----------------------------------------
 Cargo.toml             |   3 +-
 src/fmt/writer/atty.rs |  26 ++------
 3 files changed, 6 insertions(+), 171 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 3b0e0086..cca961ea 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -11,18 +11,6 @@ dependencies = [
  "memchr",
 ]
 
-[[package]]
-name = "bitflags"
-version = "1.3.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
-
-[[package]]
-name = "cc"
-version = "1.0.77"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e9f73505338f7d905b19d18738976aae232eb46b8efc15554ffc56deb5d9ebe4"
-
 [[package]]
 name = "cfg-if"
 version = "1.0.0"
@@ -34,82 +22,17 @@ name = "env_logger"
 version = "0.10.2"
 dependencies = [
  "humantime",
- "is-terminal",
  "log",
  "regex",
  "termcolor",
 ]
 
-[[package]]
-name = "errno"
-version = "0.2.8"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f639046355ee4f37944e44f60642c6f3a7efa3cf6b78c78a0d989a8ce6c396a1"
-dependencies = [
- "errno-dragonfly",
- "libc",
- "winapi",
-]
-
-[[package]]
-name = "errno-dragonfly"
-version = "0.1.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "aa68f1b12764fab894d2755d2518754e71b4fd80ecfb822714a1206c2aab39bf"
-dependencies = [
- "cc",
- "libc",
-]
-
-[[package]]
-name = "hermit-abi"
-version = "0.2.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ee512640fe35acbfb4bb779db6f0d80704c2cacfa2e39b601ef3e3f47d1ae4c7"
-dependencies = [
- "libc",
-]
-
 [[package]]
 name = "humantime"
 version = "2.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9a3a5bfb195931eeb336b2a7b4d761daec841b97f947d34394601737a7bba5e4"
 
-[[package]]
-name = "io-lifetimes"
-version = "1.0.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a7d367024b3f3414d8e01f437f704f41a9f64ab36f9067fa73e526ad4c763c87"
-dependencies = [
- "libc",
- "windows-sys",
-]
-
-[[package]]
-name = "is-terminal"
-version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "aae5bc6e2eb41c9def29a3e0f1306382807764b9b53112030eff57435667352d"
-dependencies = [
- "hermit-abi",
- "io-lifetimes",
- "rustix",
- "windows-sys",
-]
-
-[[package]]
-name = "libc"
-version = "0.2.137"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fc7fcc620a3bff7cdd7a365be3376c97191aeaccc2a603e600951e452615bf89"
-
-[[package]]
-name = "linux-raw-sys"
-version = "0.1.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8f9f08d8963a6c613f4b1a78f4f4a4dbfadf8e6545b2d72861731e4858b8b47f"
-
 [[package]]
 name = "log"
 version = "0.4.17"
@@ -142,20 +65,6 @@ version = "0.6.28"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "456c603be3e8d448b072f410900c09faf164fbce2d480456f50eea6e25f9c848"
 
-[[package]]
-name = "rustix"
-version = "0.36.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0b1fbb4dfc4eb1d390c02df47760bb19a84bb80b301ecc947ab5406394d8223e"
-dependencies = [
- "bitflags",
- "errno",
- "io-lifetimes",
- "libc",
- "linux-raw-sys",
- "windows-sys",
-]
-
 [[package]]
 name = "termcolor"
 version = "1.1.3"
@@ -195,60 +104,3 @@ name = "winapi-x86_64-pc-windows-gnu"
 version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
-
-[[package]]
-name = "windows-sys"
-version = "0.42.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5a3e1820f08b8513f676f7ab6c1f99ff312fb97b553d30ff4dd86f9f15728aa7"
-dependencies = [
- "windows_aarch64_gnullvm",
- "windows_aarch64_msvc",
- "windows_i686_gnu",
- "windows_i686_msvc",
- "windows_x86_64_gnu",
- "windows_x86_64_gnullvm",
- "windows_x86_64_msvc",
-]
-
-[[package]]
-name = "windows_aarch64_gnullvm"
-version = "0.42.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "41d2aa71f6f0cbe00ae5167d90ef3cfe66527d6f613ca78ac8024c3ccab9a19e"
-
-[[package]]
-name = "windows_aarch64_msvc"
-version = "0.42.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dd0f252f5a35cac83d6311b2e795981f5ee6e67eb1f9a7f64eb4500fbc4dcdb4"
-
-[[package]]
-name = "windows_i686_gnu"
-version = "0.42.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fbeae19f6716841636c28d695375df17562ca208b2b7d0dc47635a50ae6c5de7"
-
-[[package]]
-name = "windows_i686_msvc"
-version = "0.42.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "84c12f65daa39dd2babe6e442988fc329d6243fdce47d7d2d155b8d874862246"
-
-[[package]]
-name = "windows_x86_64_gnu"
-version = "0.42.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bf7b1b21b5362cbc318f686150e5bcea75ecedc74dd157d874d754a2ca44b0ed"
-
-[[package]]
-name = "windows_x86_64_gnullvm"
-version = "0.42.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "09d525d2ba30eeb3297665bd434a54297e4170c7f1a44cad4ef58095b4cd2028"
-
-[[package]]
-name = "windows_x86_64_msvc"
-version = "0.42.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f40009d85759725a34da6d89a94e63d7bdc50a862acf0dbc7c8e488f1edcb6f5"
diff --git a/Cargo.toml b/Cargo.toml
index 3d19de74..2f831016 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -39,7 +39,7 @@ pre-release-replacements = [
 [features]
 default = ["auto-color", "humantime", "regex"]
 color = ["dep:termcolor"]
-auto-color = ["dep:is-terminal", "color"]
+auto-color = ["color"]
 humantime = ["dep:humantime"]
 regex = ["dep:regex"]
 
@@ -48,7 +48,6 @@ log = { version = "0.4.8", features = ["std"] }
 regex = { version = "1.0.3", optional = true, default-features=false, features=["std", "perf"] }
 termcolor = { version = "1.1.1", optional = true }
 humantime = { version = "2.0.0", optional = true }
-is-terminal = { version = "0.4.0", optional = true }
 
 [[test]]
 name = "regexp_filter"
diff --git a/src/fmt/writer/atty.rs b/src/fmt/writer/atty.rs
index 1a133eef..13c994f5 100644
--- a/src/fmt/writer/atty.rs
+++ b/src/fmt/writer/atty.rs
@@ -6,28 +6,12 @@ Otherwise, assume we're not attached to anything. This effectively prevents styl
 printed.
 */
 
-#[cfg(feature = "auto-color")]
-mod imp {
-    use is_terminal::IsTerminal;
+use std::io::IsTerminal;
 
-    pub(in crate::fmt) fn is_stdout() -> bool {
-        std::io::stdout().is_terminal()
-    }
-
-    pub(in crate::fmt) fn is_stderr() -> bool {
-        std::io::stderr().is_terminal()
-    }
+pub(in crate::fmt) fn is_stdout() -> bool {
+    cfg!(feature = "auto-color") && std::io::stdout().is_terminal()
 }
 
-#[cfg(not(feature = "auto-color"))]
-mod imp {
-    pub(in crate::fmt) fn is_stdout() -> bool {
-        false
-    }
-
-    pub(in crate::fmt) fn is_stderr() -> bool {
-        false
-    }
+pub(in crate::fmt) fn is_stderr() -> bool {
+    cfg!(feature = "auto-color") && std::io::stderr().is_terminal()
 }
-
-pub(in crate::fmt) use self::imp::*;

From 5cbbff926fafac2cefd301d6f57c51aaa7b5d7d1 Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Wed, 17 Jan 2024 20:05:05 -0600
Subject: [PATCH 05/28] fix(fmt)!: Remove color support

---
 Cargo.lock                         |  41 ----
 Cargo.toml                         |   3 +-
 examples/custom_format.rs          |  12 +-
 src/fmt/mod.rs                     |  81 -------
 src/fmt/style.rs                   | 351 -----------------------------
 src/fmt/writer/buffer/mod.rs       |  13 --
 src/fmt/writer/buffer/termcolor.rs | 108 ---------
 src/fmt/writer/mod.rs              |  11 -
 src/fmt/writer/target.rs           |   2 -
 9 files changed, 3 insertions(+), 619 deletions(-)
 delete mode 100644 src/fmt/style.rs
 delete mode 100644 src/fmt/writer/buffer/termcolor.rs

diff --git a/Cargo.lock b/Cargo.lock
index cca961ea..80a265e7 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -24,7 +24,6 @@ dependencies = [
  "humantime",
  "log",
  "regex",
- "termcolor",
 ]
 
 [[package]]
@@ -64,43 +63,3 @@ name = "regex-syntax"
 version = "0.6.28"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "456c603be3e8d448b072f410900c09faf164fbce2d480456f50eea6e25f9c848"
-
-[[package]]
-name = "termcolor"
-version = "1.1.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bab24d30b911b2376f3a13cc2cd443142f0c81dda04c118693e35b3835757755"
-dependencies = [
- "winapi-util",
-]
-
-[[package]]
-name = "winapi"
-version = "0.3.9"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5c839a674fcd7a98952e593242ea400abe93992746761e38641405d28b00f419"
-dependencies = [
- "winapi-i686-pc-windows-gnu",
- "winapi-x86_64-pc-windows-gnu",
-]
-
-[[package]]
-name = "winapi-i686-pc-windows-gnu"
-version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
-
-[[package]]
-name = "winapi-util"
-version = "0.1.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "70ec6ce85bb158151cae5e5c87f95a8e97d2c0c4b001223f33a334e3ce5de178"
-dependencies = [
- "winapi",
-]
-
-[[package]]
-name = "winapi-x86_64-pc-windows-gnu"
-version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
diff --git a/Cargo.toml b/Cargo.toml
index 2f831016..499fbbb9 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -38,7 +38,7 @@ pre-release-replacements = [
 
 [features]
 default = ["auto-color", "humantime", "regex"]
-color = ["dep:termcolor"]
+color = []
 auto-color = ["color"]
 humantime = ["dep:humantime"]
 regex = ["dep:regex"]
@@ -46,7 +46,6 @@ regex = ["dep:regex"]
 [dependencies]
 log = { version = "0.4.8", features = ["std"] }
 regex = { version = "1.0.3", optional = true, default-features=false, features=["std", "perf"] }
-termcolor = { version = "1.1.1", optional = true }
 humantime = { version = "2.0.0", optional = true }
 
 [[test]]
diff --git a/examples/custom_format.rs b/examples/custom_format.rs
index cc16b336..1cc4bdec 100644
--- a/examples/custom_format.rs
+++ b/examples/custom_format.rs
@@ -19,7 +19,7 @@ If you want to control the logging output completely, see the `custom_logger` ex
 
 #[cfg(all(feature = "color", feature = "humantime"))]
 fn main() {
-    use env_logger::{fmt::Color, Builder, Env};
+    use env_logger::{Builder, Env};
 
     use std::io::Write;
 
@@ -30,17 +30,9 @@ fn main() {
 
         Builder::from_env(env)
             .format(|buf, record| {
-                let mut style = buf.style();
-                style.set_bg(Color::Yellow).set_bold(true);
-
                 let timestamp = buf.timestamp();
 
-                writeln!(
-                    buf,
-                    "My formatted log ({}): {}",
-                    timestamp,
-                    style.value(record.args())
-                )
+                writeln!(buf, "My formatted log ({}): {}", timestamp, record.args())
             })
             .init();
     }
diff --git a/src/fmt/mod.rs b/src/fmt/mod.rs
index 95feb782..dd78402f 100644
--- a/src/fmt/mod.rs
+++ b/src/fmt/mod.rs
@@ -35,19 +35,12 @@ use std::io::prelude::*;
 use std::rc::Rc;
 use std::{fmt, io, mem};
 
-#[cfg(feature = "color")]
-use log::Level;
 use log::Record;
 
 #[cfg(feature = "humantime")]
 mod humantime;
 pub(crate) mod writer;
 
-#[cfg(feature = "color")]
-mod style;
-#[cfg(feature = "color")]
-pub use style::{Color, Style, StyledValue};
-
 #[cfg(feature = "humantime")]
 pub use self::humantime::Timestamp;
 pub use self::writer::Target;
@@ -126,62 +119,6 @@ impl Formatter {
     }
 }
 
-#[cfg(feature = "color")]
-impl Formatter {
-    /// Begin a new [`Style`].
-    ///
-    /// # Examples
-    ///
-    /// Create a bold, red colored style and use it to print the log level:
-    ///
-    /// ```
-    /// use std::io::Write;
-    /// use env_logger::fmt::Color;
-    ///
-    /// let mut builder = env_logger::Builder::new();
-    ///
-    /// builder.format(|buf, record| {
-    ///     let mut level_style = buf.style();
-    ///
-    ///     level_style.set_color(Color::Red).set_bold(true);
-    ///
-    ///     writeln!(buf, "{}: {}",
-    ///         level_style.value(record.level()),
-    ///         record.args())
-    /// });
-    /// ```
-    ///
-    /// [`Style`]: struct.Style.html
-    pub fn style(&self) -> Style {
-        Style {
-            buf: self.buf.clone(),
-            spec: termcolor::ColorSpec::new(),
-        }
-    }
-
-    /// Get the default [`Style`] for the given level.
-    ///
-    /// The style can be used to print other values besides the level.
-    pub fn default_level_style(&self, level: Level) -> Style {
-        let mut level_style = self.style();
-        match level {
-            Level::Trace => level_style.set_color(Color::Cyan),
-            Level::Debug => level_style.set_color(Color::Blue),
-            Level::Info => level_style.set_color(Color::Green),
-            Level::Warn => level_style.set_color(Color::Yellow),
-            Level::Error => level_style.set_color(Color::Red).set_bold(true),
-        };
-        level_style
-    }
-
-    /// Get a printable [`Style`] for the given level.
-    ///
-    /// The style can only be used to print the level.
-    pub fn default_styled_level(&self, level: Level) -> StyledValue<'static, Level> {
-        self.default_level_style(level).into_value(level)
-    }
-}
-
 impl Write for Formatter {
     fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
         self.buf.borrow_mut().write(buf)
@@ -264,9 +201,6 @@ impl Default for Builder {
     }
 }
 
-#[cfg(feature = "color")]
-type SubtleStyle = StyledValue<'static, &'static str>;
-#[cfg(not(feature = "color"))]
 type SubtleStyle = &'static str;
 
 /// The default format.
@@ -295,16 +229,6 @@ impl<'a> DefaultFormat<'a> {
     }
 
     fn subtle_style(&self, text: &'static str) -> SubtleStyle {
-        #[cfg(feature = "color")]
-        {
-            self.buf
-                .style()
-                .set_color(Color::Black)
-                .set_intense(true)
-                .clone()
-                .into_value(text)
-        }
-        #[cfg(not(feature = "color"))]
         {
             text
         }
@@ -330,11 +254,6 @@ impl<'a> DefaultFormat<'a> {
         }
 
         let level = {
-            #[cfg(feature = "color")]
-            {
-                self.buf.default_styled_level(record.level())
-            }
-            #[cfg(not(feature = "color"))]
             {
                 record.level()
             }
diff --git a/src/fmt/style.rs b/src/fmt/style.rs
deleted file mode 100644
index dd4463ac..00000000
--- a/src/fmt/style.rs
+++ /dev/null
@@ -1,351 +0,0 @@
-use std::borrow::Cow;
-use std::cell::RefCell;
-use std::fmt;
-use std::rc::Rc;
-
-use super::Buffer;
-
-/// A set of styles to apply to the terminal output.
-///
-/// Call [`Formatter::style`] to get a `Style` and use the builder methods to
-/// set styling properties, like [color] and [weight].
-/// To print a value using the style, wrap it in a call to [`value`] when the log
-/// record is formatted.
-///
-/// # Examples
-///
-/// Create a bold, red colored style and use it to print the log level:
-///
-/// ```
-/// use std::io::Write;
-/// use env_logger::fmt::Color;
-///
-/// let mut builder = env_logger::Builder::new();
-///
-/// builder.format(|buf, record| {
-///     let mut level_style = buf.style();
-///
-///     level_style.set_color(Color::Red).set_bold(true);
-///
-///     writeln!(buf, "{}: {}",
-///         level_style.value(record.level()),
-///         record.args())
-/// });
-/// ```
-///
-/// Styles can be re-used to output multiple values:
-///
-/// ```
-/// use std::io::Write;
-/// use env_logger::fmt::Color;
-///
-/// let mut builder = env_logger::Builder::new();
-///
-/// builder.format(|buf, record| {
-///     let mut bold = buf.style();
-///
-///     bold.set_bold(true);
-///
-///     writeln!(buf, "{}: {} {}",
-///         bold.value(record.level()),
-///         bold.value("some bold text"),
-///         record.args())
-/// });
-/// ```
-///
-/// [`Formatter::style`]: struct.Formatter.html#method.style
-/// [color]: #method.set_color
-/// [weight]: #method.set_bold
-/// [`value`]: #method.value
-#[derive(Clone)]
-pub struct Style {
-    pub(in crate::fmt) buf: Rc<RefCell<Buffer>>,
-    pub(in crate::fmt) spec: termcolor::ColorSpec,
-}
-
-impl Style {
-    /// Set the text color.
-    ///
-    /// # Examples
-    ///
-    /// Create a style with red text:
-    ///
-    /// ```
-    /// use std::io::Write;
-    /// use env_logger::fmt::Color;
-    ///
-    /// let mut builder = env_logger::Builder::new();
-    ///
-    /// builder.format(|buf, record| {
-    ///     let mut style = buf.style();
-    ///
-    ///     style.set_color(Color::Red);
-    ///
-    ///     writeln!(buf, "{}", style.value(record.args()))
-    /// });
-    /// ```
-    pub fn set_color(&mut self, color: Color) -> &mut Style {
-        self.spec.set_fg(Some(color.into_termcolor()));
-        self
-    }
-
-    /// Set the text weight.
-    ///
-    /// If `yes` is true then text will be written in bold.
-    /// If `yes` is false then text will be written in the default weight.
-    ///
-    /// # Examples
-    ///
-    /// Create a style with bold text:
-    ///
-    /// ```
-    /// use std::io::Write;
-    ///
-    /// let mut builder = env_logger::Builder::new();
-    ///
-    /// builder.format(|buf, record| {
-    ///     let mut style = buf.style();
-    ///
-    ///     style.set_bold(true);
-    ///
-    ///     writeln!(buf, "{}", style.value(record.args()))
-    /// });
-    /// ```
-    pub fn set_bold(&mut self, yes: bool) -> &mut Style {
-        self.spec.set_bold(yes);
-        self
-    }
-
-    /// Set the text intensity.
-    ///
-    /// If `yes` is true then text will be written in a brighter color.
-    /// If `yes` is false then text will be written in the default color.
-    ///
-    /// # Examples
-    ///
-    /// Create a style with intense text:
-    ///
-    /// ```
-    /// use std::io::Write;
-    ///
-    /// let mut builder = env_logger::Builder::new();
-    ///
-    /// builder.format(|buf, record| {
-    ///     let mut style = buf.style();
-    ///
-    ///     style.set_intense(true);
-    ///
-    ///     writeln!(buf, "{}", style.value(record.args()))
-    /// });
-    /// ```
-    pub fn set_intense(&mut self, yes: bool) -> &mut Style {
-        self.spec.set_intense(yes);
-        self
-    }
-
-    /// Set whether the text is dimmed.
-    ///
-    /// If `yes` is true then text will be written in a dimmer color.
-    /// If `yes` is false then text will be written in the default color.
-    ///
-    /// # Examples
-    ///
-    /// Create a style with dimmed text:
-    ///
-    /// ```
-    /// use std::io::Write;
-    ///
-    /// let mut builder = env_logger::Builder::new();
-    ///
-    /// builder.format(|buf, record| {
-    ///     let mut style = buf.style();
-    ///
-    ///     style.set_dimmed(true);
-    ///
-    ///     writeln!(buf, "{}", style.value(record.args()))
-    /// });
-    /// ```
-    pub fn set_dimmed(&mut self, yes: bool) -> &mut Style {
-        self.spec.set_dimmed(yes);
-        self
-    }
-
-    /// Set the background color.
-    ///
-    /// # Examples
-    ///
-    /// Create a style with a yellow background:
-    ///
-    /// ```
-    /// use std::io::Write;
-    /// use env_logger::fmt::Color;
-    ///
-    /// let mut builder = env_logger::Builder::new();
-    ///
-    /// builder.format(|buf, record| {
-    ///     let mut style = buf.style();
-    ///
-    ///     style.set_bg(Color::Yellow);
-    ///
-    ///     writeln!(buf, "{}", style.value(record.args()))
-    /// });
-    /// ```
-    pub fn set_bg(&mut self, color: Color) -> &mut Style {
-        self.spec.set_bg(Some(color.into_termcolor()));
-        self
-    }
-
-    /// Wrap a value in the style.
-    ///
-    /// The same `Style` can be used to print multiple different values.
-    ///
-    /// # Examples
-    ///
-    /// Create a bold, red colored style and use it to print the log level:
-    ///
-    /// ```
-    /// use std::io::Write;
-    /// use env_logger::fmt::Color;
-    ///
-    /// let mut builder = env_logger::Builder::new();
-    ///
-    /// builder.format(|buf, record| {
-    ///     let mut style = buf.style();
-    ///
-    ///     style.set_color(Color::Red).set_bold(true);
-    ///
-    ///     writeln!(buf, "{}: {}",
-    ///         style.value(record.level()),
-    ///         record.args())
-    /// });
-    /// ```
-    pub fn value<T>(&self, value: T) -> StyledValue<T> {
-        StyledValue {
-            style: Cow::Borrowed(self),
-            value,
-        }
-    }
-
-    /// Wrap a value in the style by taking ownership of it.
-    pub(crate) fn into_value<T>(self, value: T) -> StyledValue<'static, T> {
-        StyledValue {
-            style: Cow::Owned(self),
-            value,
-        }
-    }
-}
-
-impl fmt::Debug for Style {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        f.debug_struct("Style").field("spec", &self.spec).finish()
-    }
-}
-
-/// A value that can be printed using the given styles.
-///
-/// It is the result of calling [`Style::value`].
-///
-/// [`Style::value`]: struct.Style.html#method.value
-pub struct StyledValue<'a, T> {
-    style: Cow<'a, Style>,
-    value: T,
-}
-
-impl<'a, T> StyledValue<'a, T> {
-    fn write_fmt<F>(&self, f: F) -> fmt::Result
-    where
-        F: FnOnce() -> fmt::Result,
-    {
-        self.style
-            .buf
-            .borrow_mut()
-            .set_color(&self.style.spec)
-            .map_err(|_| fmt::Error)?;
-
-        // Always try to reset the terminal style, even if writing failed
-        let write = f();
-        let reset = self.style.buf.borrow_mut().reset().map_err(|_| fmt::Error);
-
-        write.and(reset)
-    }
-}
-
-macro_rules! impl_styled_value_fmt {
-    ($($fmt_trait:path),*) => {
-        $(
-            impl<'a, T: $fmt_trait> $fmt_trait for StyledValue<'a, T> {
-                fn fmt(&self, f: &mut fmt::Formatter)->fmt::Result {
-                    self.write_fmt(|| T::fmt(&self.value, f))
-                }
-            }
-        )*
-    };
-}
-
-impl_styled_value_fmt!(
-    fmt::Debug,
-    fmt::Display,
-    fmt::Pointer,
-    fmt::Octal,
-    fmt::Binary,
-    fmt::UpperHex,
-    fmt::LowerHex,
-    fmt::UpperExp,
-    fmt::LowerExp
-);
-
-// The `Color` type is copied from https://github.com/BurntSushi/termcolor
-
-/// The set of available colors for the terminal foreground/background.
-///
-/// The `Ansi256` and `Rgb` colors will only output the correct codes when
-/// paired with the `Ansi` `WriteColor` implementation.
-///
-/// The `Ansi256` and `Rgb` color types are not supported when writing colors
-/// on Windows using the console. If they are used on Windows, then they are
-/// silently ignored and no colors will be emitted.
-///
-/// This set may expand over time.
-///
-/// This type has a `FromStr` impl that can parse colors from their human
-/// readable form. The format is as follows:
-///
-/// 1. Any of the explicitly listed colors in English. They are matched
-///    case insensitively.
-/// 2. A single 8-bit integer, in either decimal or hexadecimal format.
-/// 3. A triple of 8-bit integers separated by a comma, where each integer is
-///    in decimal or hexadecimal format.
-///
-/// Hexadecimal numbers are written with a `0x` prefix.
-#[allow(missing_docs)]
-#[non_exhaustive]
-#[derive(Clone, Debug, Eq, PartialEq)]
-pub enum Color {
-    Black,
-    Blue,
-    Green,
-    Red,
-    Cyan,
-    Magenta,
-    Yellow,
-    White,
-    Ansi256(u8),
-    Rgb(u8, u8, u8),
-}
-
-impl Color {
-    fn into_termcolor(self) -> termcolor::Color {
-        match self {
-            Color::Black => termcolor::Color::Black,
-            Color::Blue => termcolor::Color::Blue,
-            Color::Green => termcolor::Color::Green,
-            Color::Red => termcolor::Color::Red,
-            Color::Cyan => termcolor::Color::Cyan,
-            Color::Magenta => termcolor::Color::Magenta,
-            Color::Yellow => termcolor::Color::Yellow,
-            Color::White => termcolor::Color::White,
-            Color::Ansi256(value) => termcolor::Color::Ansi256(value),
-            Color::Rgb(r, g, b) => termcolor::Color::Rgb(r, g, b),
-        }
-    }
-}
diff --git a/src/fmt/writer/buffer/mod.rs b/src/fmt/writer/buffer/mod.rs
index 4e678b2d..d0dbb5f5 100644
--- a/src/fmt/writer/buffer/mod.rs
+++ b/src/fmt/writer/buffer/mod.rs
@@ -1,15 +1,2 @@
-/*
-This internal module contains the style and terminal writing implementation.
-
-Its public API is available when the `termcolor` crate is available.
-The terminal printing is shimmed when the `termcolor` crate is not available.
-*/
-
-#[cfg(feature = "color")]
-mod termcolor;
-#[cfg(feature = "color")]
-pub(in crate::fmt) use self::termcolor::*;
-#[cfg(not(feature = "color"))]
 mod plain;
-#[cfg(not(feature = "color"))]
 pub(in crate::fmt) use plain::*;
diff --git a/src/fmt/writer/buffer/termcolor.rs b/src/fmt/writer/buffer/termcolor.rs
deleted file mode 100644
index 648ed16f..00000000
--- a/src/fmt/writer/buffer/termcolor.rs
+++ /dev/null
@@ -1,108 +0,0 @@
-use std::io::{self, Write};
-use std::sync::Mutex;
-
-use termcolor::{self, ColorSpec, WriteColor};
-
-use crate::fmt::writer::{WritableTarget, WriteStyle};
-
-pub(in crate::fmt::writer) struct BufferWriter {
-    inner: termcolor::BufferWriter,
-    uncolored_target: Option<WritableTarget>,
-    write_style: WriteStyle,
-}
-
-impl BufferWriter {
-    pub(in crate::fmt::writer) fn stderr(is_test: bool, write_style: WriteStyle) -> Self {
-        BufferWriter {
-            inner: termcolor::BufferWriter::stderr(write_style.into_color_choice()),
-            uncolored_target: if is_test {
-                Some(WritableTarget::PrintStderr)
-            } else {
-                None
-            },
-            write_style,
-        }
-    }
-
-    pub(in crate::fmt::writer) fn stdout(is_test: bool, write_style: WriteStyle) -> Self {
-        BufferWriter {
-            inner: termcolor::BufferWriter::stdout(write_style.into_color_choice()),
-            uncolored_target: if is_test {
-                Some(WritableTarget::PrintStdout)
-            } else {
-                None
-            },
-            write_style,
-        }
-    }
-
-    pub(in crate::fmt::writer) fn pipe(pipe: Box<Mutex<dyn io::Write + Send + 'static>>) -> Self {
-        let write_style = WriteStyle::Never;
-        BufferWriter {
-            // The inner Buffer is never printed from, but it is still needed to handle coloring and other formatting
-            inner: termcolor::BufferWriter::stderr(write_style.into_color_choice()),
-            uncolored_target: Some(WritableTarget::Pipe(pipe)),
-            write_style,
-        }
-    }
-
-    pub(in crate::fmt::writer) fn write_style(&self) -> WriteStyle {
-        self.write_style
-    }
-
-    pub(in crate::fmt::writer) fn buffer(&self) -> Buffer {
-        Buffer {
-            inner: self.inner.buffer(),
-            has_uncolored_target: self.uncolored_target.is_some(),
-        }
-    }
-
-    pub(in crate::fmt::writer) fn print(&self, buf: &Buffer) -> io::Result<()> {
-        if let Some(target) = &self.uncolored_target {
-            target.print(buf)
-        } else {
-            self.inner.print(&buf.inner)
-        }
-    }
-}
-
-pub(in crate::fmt) struct Buffer {
-    inner: termcolor::Buffer,
-    has_uncolored_target: bool,
-}
-
-impl Buffer {
-    pub(in crate::fmt) fn clear(&mut self) {
-        self.inner.clear()
-    }
-
-    pub(in crate::fmt) fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
-        self.inner.write(buf)
-    }
-
-    pub(in crate::fmt) fn flush(&mut self) -> io::Result<()> {
-        self.inner.flush()
-    }
-
-    pub(in crate::fmt) fn as_bytes(&self) -> &[u8] {
-        self.inner.as_slice()
-    }
-
-    pub(in crate::fmt) fn set_color(&mut self, spec: &ColorSpec) -> io::Result<()> {
-        // Ignore styles for test captured logs because they can't be printed
-        if !self.has_uncolored_target {
-            self.inner.set_color(spec)
-        } else {
-            Ok(())
-        }
-    }
-
-    pub(in crate::fmt) fn reset(&mut self) -> io::Result<()> {
-        // Ignore styles for test captured logs because they can't be printed
-        if !self.has_uncolored_target {
-            self.inner.reset()
-        } else {
-            Ok(())
-        }
-    }
-}
diff --git a/src/fmt/writer/mod.rs b/src/fmt/writer/mod.rs
index 4195e788..74ab560d 100644
--- a/src/fmt/writer/mod.rs
+++ b/src/fmt/writer/mod.rs
@@ -26,17 +26,6 @@ pub enum WriteStyle {
 
 
 
-#[cfg(feature = "color")]
-impl WriteStyle {
-    fn into_color_choice(self) -> ::termcolor::ColorChoice {
-        match self {
-            WriteStyle::Always => ::termcolor::ColorChoice::Always,
-            WriteStyle::Auto => ::termcolor::ColorChoice::Auto,
-            WriteStyle::Never => ::termcolor::ColorChoice::Never,
-        }
-    }
-}
-
 /// A terminal target with color awareness.
 pub(crate) struct Writer {
     inner: BufferWriter,
diff --git a/src/fmt/writer/target.rs b/src/fmt/writer/target.rs
index c3fe4825..0b806f9e 100644
--- a/src/fmt/writer/target.rs
+++ b/src/fmt/writer/target.rs
@@ -32,12 +32,10 @@ impl std::fmt::Debug for Target {
 /// Same as `Target`, except the pipe is wrapped in a mutex for interior mutability.
 pub(super) enum WritableTarget {
     /// Logs will be written to standard output.
-    #[allow(dead_code)]
     WriteStdout,
     /// Logs will be printed to standard output.
     PrintStdout,
     /// Logs will be written to standard error.
-    #[allow(dead_code)]
     WriteStderr,
     /// Logs will be printed to standard error.
     PrintStderr,

From 0016e2c51212ea192bec1beaeb5e01fef5285eb9 Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Wed, 17 Jan 2024 20:21:11 -0600
Subject: [PATCH 06/28] refactor(fmt): Flatten mods

---
 src/fmt/writer/{buffer/plain.rs => buffer.rs} | 0
 src/fmt/writer/buffer/mod.rs                  | 2 --
 2 files changed, 2 deletions(-)
 rename src/fmt/writer/{buffer/plain.rs => buffer.rs} (100%)
 delete mode 100644 src/fmt/writer/buffer/mod.rs

diff --git a/src/fmt/writer/buffer/plain.rs b/src/fmt/writer/buffer.rs
similarity index 100%
rename from src/fmt/writer/buffer/plain.rs
rename to src/fmt/writer/buffer.rs
diff --git a/src/fmt/writer/buffer/mod.rs b/src/fmt/writer/buffer/mod.rs
deleted file mode 100644
index d0dbb5f5..00000000
--- a/src/fmt/writer/buffer/mod.rs
+++ /dev/null
@@ -1,2 +0,0 @@
-mod plain;
-pub(in crate::fmt) use plain::*;

From 1c50358db72afd46bf38922279ed7d492f472b29 Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Wed, 17 Jan 2024 21:12:39 -0600
Subject: [PATCH 07/28] refactor(fmt): Inline the print call

---
 src/fmt/writer/buffer.rs | 28 +++++++++++++++++++++++++++-
 src/fmt/writer/target.rs | 32 --------------------------------
 2 files changed, 27 insertions(+), 33 deletions(-)

diff --git a/src/fmt/writer/buffer.rs b/src/fmt/writer/buffer.rs
index 99056783..64f9f087 100644
--- a/src/fmt/writer/buffer.rs
+++ b/src/fmt/writer/buffer.rs
@@ -42,7 +42,33 @@ impl BufferWriter {
     }
 
     pub(in crate::fmt::writer) fn print(&self, buf: &Buffer) -> io::Result<()> {
-        self.target.print(buf)
+        use std::io::Write as _;
+
+        let buf = buf.as_bytes();
+        match &self.target {
+            WritableTarget::WriteStdout => {
+                let stream = std::io::stdout();
+                let mut stream = stream.lock();
+                stream.write_all(buf)?;
+                stream.flush()?;
+            }
+            WritableTarget::PrintStdout => print!("{}", String::from_utf8_lossy(buf)),
+            WritableTarget::WriteStderr => {
+                let stream = std::io::stderr();
+                let mut stream = stream.lock();
+                stream.write_all(buf)?;
+                stream.flush()?;
+            }
+            WritableTarget::PrintStderr => eprint!("{}", String::from_utf8_lossy(buf)),
+            // Safety: If the target type is `Pipe`, `target_pipe` will always be non-empty.
+            WritableTarget::Pipe(pipe) => {
+                let mut stream = pipe.lock().unwrap();
+                stream.write_all(buf)?;
+                stream.flush()?;
+            }
+        }
+
+        Ok(())
     }
 }
 
diff --git a/src/fmt/writer/target.rs b/src/fmt/writer/target.rs
index 0b806f9e..02f69c75 100644
--- a/src/fmt/writer/target.rs
+++ b/src/fmt/writer/target.rs
@@ -43,38 +43,6 @@ pub(super) enum WritableTarget {
     Pipe(Box<std::sync::Mutex<dyn std::io::Write + Send + 'static>>),
 }
 
-impl WritableTarget {
-    pub(super) fn print(&self, buf: &super::Buffer) -> std::io::Result<()> {
-        use std::io::Write as _;
-
-        let buf = buf.as_bytes();
-        match self {
-            WritableTarget::WriteStdout => {
-                let stream = std::io::stdout();
-                let mut stream = stream.lock();
-                stream.write_all(buf)?;
-                stream.flush()?;
-            }
-            WritableTarget::PrintStdout => print!("{}", String::from_utf8_lossy(buf)),
-            WritableTarget::WriteStderr => {
-                let stream = std::io::stderr();
-                let mut stream = stream.lock();
-                stream.write_all(buf)?;
-                stream.flush()?;
-            }
-            WritableTarget::PrintStderr => eprint!("{}", String::from_utf8_lossy(buf)),
-            // Safety: If the target type is `Pipe`, `target_pipe` will always be non-empty.
-            WritableTarget::Pipe(pipe) => {
-                let mut stream = pipe.lock().unwrap();
-                stream.write_all(buf)?;
-                stream.flush()?;
-            }
-        }
-
-        Ok(())
-    }
-}
-
 impl std::fmt::Debug for WritableTarget {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         write!(

From f3de55b9eb44a0da90242961e581bac58817cc9c Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Wed, 17 Jan 2024 21:40:58 -0600
Subject: [PATCH 08/28] refactor(fmt): Pull in Target to its only use

---
 src/fmt/writer/buffer.rs | 34 +++++++++++++++++++++++++++++++++-
 src/fmt/writer/mod.rs    |  1 -
 src/fmt/writer/target.rs | 34 ----------------------------------
 3 files changed, 33 insertions(+), 36 deletions(-)

diff --git a/src/fmt/writer/buffer.rs b/src/fmt/writer/buffer.rs
index 64f9f087..9b7cbf3c 100644
--- a/src/fmt/writer/buffer.rs
+++ b/src/fmt/writer/buffer.rs
@@ -1,6 +1,6 @@
 use std::{io, sync::Mutex};
 
-use crate::fmt::writer::{WritableTarget, WriteStyle};
+use crate::fmt::writer::WriteStyle;
 
 pub(in crate::fmt::writer) struct BufferWriter {
     target: WritableTarget,
@@ -92,3 +92,35 @@ impl Buffer {
         &self.0
     }
 }
+
+/// Log target, either `stdout`, `stderr` or a custom pipe.
+///
+/// Same as `Target`, except the pipe is wrapped in a mutex for interior mutability.
+pub(super) enum WritableTarget {
+    /// Logs will be written to standard output.
+    WriteStdout,
+    /// Logs will be printed to standard output.
+    PrintStdout,
+    /// Logs will be written to standard error.
+    WriteStderr,
+    /// Logs will be printed to standard error.
+    PrintStderr,
+    /// Logs will be sent to a custom pipe.
+    Pipe(Box<std::sync::Mutex<dyn std::io::Write + Send + 'static>>),
+}
+
+impl std::fmt::Debug for WritableTarget {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            "{}",
+            match self {
+                Self::WriteStdout => "stdout",
+                Self::PrintStdout => "stdout",
+                Self::WriteStderr => "stderr",
+                Self::PrintStderr => "stderr",
+                Self::Pipe(_) => "pipe",
+            }
+        )
+    }
+}
diff --git a/src/fmt/writer/mod.rs b/src/fmt/writer/mod.rs
index 74ab560d..f5f7de32 100644
--- a/src/fmt/writer/mod.rs
+++ b/src/fmt/writer/mod.rs
@@ -9,7 +9,6 @@ use std::{fmt, io, mem, sync::Mutex};
 pub(super) use self::buffer::Buffer;
 
 pub use target::Target;
-use target::WritableTarget;
 
 /// Whether or not to print styles to the target.
 #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
diff --git a/src/fmt/writer/target.rs b/src/fmt/writer/target.rs
index 02f69c75..a1220ffe 100644
--- a/src/fmt/writer/target.rs
+++ b/src/fmt/writer/target.rs
@@ -11,8 +11,6 @@ pub enum Target {
     Pipe(Box<dyn std::io::Write + Send + 'static>),
 }
 
-
-
 impl std::fmt::Debug for Target {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         write!(
@@ -26,35 +24,3 @@ impl std::fmt::Debug for Target {
         )
     }
 }
-
-/// Log target, either `stdout`, `stderr` or a custom pipe.
-///
-/// Same as `Target`, except the pipe is wrapped in a mutex for interior mutability.
-pub(super) enum WritableTarget {
-    /// Logs will be written to standard output.
-    WriteStdout,
-    /// Logs will be printed to standard output.
-    PrintStdout,
-    /// Logs will be written to standard error.
-    WriteStderr,
-    /// Logs will be printed to standard error.
-    PrintStderr,
-    /// Logs will be sent to a custom pipe.
-    Pipe(Box<std::sync::Mutex<dyn std::io::Write + Send + 'static>>),
-}
-
-impl std::fmt::Debug for WritableTarget {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        write!(
-            f,
-            "{}",
-            match self {
-                Self::WriteStdout => "stdout",
-                Self::PrintStdout => "stdout",
-                Self::WriteStderr => "stderr",
-                Self::PrintStderr => "stderr",
-                Self::Pipe(_) => "pipe",
-            }
-        )
-    }
-}

From bce8463804c027d2e2aca8a07ef6c4cd29ab98e9 Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Wed, 17 Jan 2024 20:30:39 -0600
Subject: [PATCH 09/28] feat(fmt): Add back color support

This also adds support for `NO_COLOR` and `CLICOLOR_FORCE`, see https://bixense.com/clicolors/
---
 Cargo.lock               | 127 +++++++++++++++++++++++++++++++++++++++
 Cargo.toml               |   5 +-
 src/fmt/writer/atty.rs   |  17 ------
 src/fmt/writer/buffer.rs |  44 ++++++++++++--
 src/fmt/writer/mod.rs    |  59 ++++++++++++------
 src/logger.rs            |   3 +
 6 files changed, 213 insertions(+), 42 deletions(-)
 delete mode 100644 src/fmt/writer/atty.rs

diff --git a/Cargo.lock b/Cargo.lock
index 80a265e7..ac42c663 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -11,16 +11,71 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "anstream"
+version = "0.6.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6e2e1ebcb11de5c03c67de28a7df593d32191b44939c482e97702baaaa6ab6a5"
+dependencies = [
+ "anstyle",
+ "anstyle-parse",
+ "anstyle-query",
+ "anstyle-wincon",
+ "colorchoice",
+ "utf8parse",
+]
+
+[[package]]
+name = "anstyle"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7079075b41f533b8c61d2a4d073c4676e1f8b249ff94a393b0595db304e0dd87"
+
+[[package]]
+name = "anstyle-parse"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c75ac65da39e5fe5ab759307499ddad880d724eed2f6ce5b5e8a26f4f387928c"
+dependencies = [
+ "utf8parse",
+]
+
+[[package]]
+name = "anstyle-query"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e28923312444cdd728e4738b3f9c9cac739500909bb3d3c94b43551b16517648"
+dependencies = [
+ "windows-sys",
+]
+
+[[package]]
+name = "anstyle-wincon"
+version = "3.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1cd54b81ec8d6180e24654d0b371ad22fc3dd083b6ff8ba325b72e00c87660a7"
+dependencies = [
+ "anstyle",
+ "windows-sys",
+]
+
 [[package]]
 name = "cfg-if"
 version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
+[[package]]
+name = "colorchoice"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "acbf1af155f9b9ef647e42cdc158db4b64a1b61f743629225fde6f3e0be2a7c7"
+
 [[package]]
 name = "env_logger"
 version = "0.10.2"
 dependencies = [
+ "anstream",
  "humantime",
  "log",
  "regex",
@@ -63,3 +118,75 @@ name = "regex-syntax"
 version = "0.6.28"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "456c603be3e8d448b072f410900c09faf164fbce2d480456f50eea6e25f9c848"
+
+[[package]]
+name = "utf8parse"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "711b9620af191e0cdc7468a8d14e709c3dcdb115b36f838e601583af800a370a"
+
+[[package]]
+name = "windows-sys"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "282be5f36a8ce781fad8c8ae18fa3f9beff57ec1b52cb3de0789201425d9a33d"
+dependencies = [
+ "windows-targets",
+]
+
+[[package]]
+name = "windows-targets"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8a18201040b24831fbb9e4eb208f8892e1f50a37feb53cc7ff887feb8f50e7cd"
+dependencies = [
+ "windows_aarch64_gnullvm",
+ "windows_aarch64_msvc",
+ "windows_i686_gnu",
+ "windows_i686_msvc",
+ "windows_x86_64_gnu",
+ "windows_x86_64_gnullvm",
+ "windows_x86_64_msvc",
+]
+
+[[package]]
+name = "windows_aarch64_gnullvm"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cb7764e35d4db8a7921e09562a0304bf2f93e0a51bfccee0bd0bb0b666b015ea"
+
+[[package]]
+name = "windows_aarch64_msvc"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bbaa0368d4f1d2aaefc55b6fcfee13f41544ddf36801e793edbbfd7d7df075ef"
+
+[[package]]
+name = "windows_i686_gnu"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a28637cb1fa3560a16915793afb20081aba2c92ee8af57b4d5f28e4b3e7df313"
+
+[[package]]
+name = "windows_i686_msvc"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ffe5e8e31046ce6230cc7215707b816e339ff4d4d67c65dffa206fd0f7aa7b9a"
+
+[[package]]
+name = "windows_x86_64_gnu"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3d6fa32db2bc4a2f5abeacf2b69f7992cd09dca97498da74a151a3132c26befd"
+
+[[package]]
+name = "windows_x86_64_gnullvm"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1a657e1e9d3f514745a572a6846d3c7aa7dbe1658c056ed9c3344c4109a6949e"
+
+[[package]]
+name = "windows_x86_64_msvc"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dff9641d1cd4be8d1a070daf9e3773c5f67e78b4d9d42263020c057706765c04"
diff --git a/Cargo.toml b/Cargo.toml
index 499fbbb9..06871c62 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -38,8 +38,8 @@ pre-release-replacements = [
 
 [features]
 default = ["auto-color", "humantime", "regex"]
-color = []
-auto-color = ["color"]
+color = ["dep:anstream"]
+auto-color = ["color", "anstream/auto"]
 humantime = ["dep:humantime"]
 regex = ["dep:regex"]
 
@@ -47,6 +47,7 @@ regex = ["dep:regex"]
 log = { version = "0.4.8", features = ["std"] }
 regex = { version = "1.0.3", optional = true, default-features=false, features=["std", "perf"] }
 humantime = { version = "2.0.0", optional = true }
+anstream = { version = "0.6.11", default-features = false, features = ["wincon"], optional = true }
 
 [[test]]
 name = "regexp_filter"
diff --git a/src/fmt/writer/atty.rs b/src/fmt/writer/atty.rs
deleted file mode 100644
index 13c994f5..00000000
--- a/src/fmt/writer/atty.rs
+++ /dev/null
@@ -1,17 +0,0 @@
-/*
-This internal module contains the terminal detection implementation.
-
-If the `auto-color` feature is enabled then we detect whether we're attached to a particular TTY.
-Otherwise, assume we're not attached to anything. This effectively prevents styles from being
-printed.
-*/
-
-use std::io::IsTerminal;
-
-pub(in crate::fmt) fn is_stdout() -> bool {
-    cfg!(feature = "auto-color") && std::io::stdout().is_terminal()
-}
-
-pub(in crate::fmt) fn is_stderr() -> bool {
-    cfg!(feature = "auto-color") && std::io::stderr().is_terminal()
-}
diff --git a/src/fmt/writer/buffer.rs b/src/fmt/writer/buffer.rs
index 9b7cbf3c..aeffde05 100644
--- a/src/fmt/writer/buffer.rs
+++ b/src/fmt/writer/buffer.rs
@@ -4,37 +4,41 @@ use crate::fmt::writer::WriteStyle;
 
 pub(in crate::fmt::writer) struct BufferWriter {
     target: WritableTarget,
+    write_style: WriteStyle,
 }
 
 impl BufferWriter {
-    pub(in crate::fmt::writer) fn stderr(is_test: bool, _write_style: WriteStyle) -> Self {
+    pub(in crate::fmt::writer) fn stderr(is_test: bool, write_style: WriteStyle) -> Self {
         BufferWriter {
             target: if is_test {
                 WritableTarget::PrintStderr
             } else {
                 WritableTarget::WriteStderr
             },
+            write_style,
         }
     }
 
-    pub(in crate::fmt::writer) fn stdout(is_test: bool, _write_style: WriteStyle) -> Self {
+    pub(in crate::fmt::writer) fn stdout(is_test: bool, write_style: WriteStyle) -> Self {
         BufferWriter {
             target: if is_test {
                 WritableTarget::PrintStdout
             } else {
                 WritableTarget::WriteStdout
             },
+            write_style,
         }
     }
 
     pub(in crate::fmt::writer) fn pipe(pipe: Box<Mutex<dyn io::Write + Send + 'static>>) -> Self {
         BufferWriter {
             target: WritableTarget::Pipe(pipe),
+            write_style: WriteStyle::Never,
         }
     }
 
     pub(in crate::fmt::writer) fn write_style(&self) -> WriteStyle {
-        WriteStyle::Never
+        self.write_style
     }
 
     pub(in crate::fmt::writer) fn buffer(&self) -> Buffer {
@@ -48,19 +52,36 @@ impl BufferWriter {
         match &self.target {
             WritableTarget::WriteStdout => {
                 let stream = std::io::stdout();
+                #[cfg(feature = "color")]
+                let stream = anstream::AutoStream::new(stream, self.write_style.into());
                 let mut stream = stream.lock();
                 stream.write_all(buf)?;
                 stream.flush()?;
             }
-            WritableTarget::PrintStdout => print!("{}", String::from_utf8_lossy(buf)),
+            WritableTarget::PrintStdout => {
+                #[cfg(feature = "color")]
+                let buf = adapt(buf, self.write_style)?;
+                #[cfg(feature = "color")]
+                let buf = &buf;
+                let buf = String::from_utf8_lossy(buf);
+                print!("{}", buf);
+            }
             WritableTarget::WriteStderr => {
                 let stream = std::io::stderr();
+                #[cfg(feature = "color")]
+                let stream = anstream::AutoStream::new(stream, self.write_style.into());
                 let mut stream = stream.lock();
                 stream.write_all(buf)?;
                 stream.flush()?;
             }
-            WritableTarget::PrintStderr => eprint!("{}", String::from_utf8_lossy(buf)),
-            // Safety: If the target type is `Pipe`, `target_pipe` will always be non-empty.
+            WritableTarget::PrintStderr => {
+                #[cfg(feature = "color")]
+                let buf = adapt(buf, self.write_style)?;
+                #[cfg(feature = "color")]
+                let buf = &buf;
+                let buf = String::from_utf8_lossy(buf);
+                eprint!("{}", buf);
+            }
             WritableTarget::Pipe(pipe) => {
                 let mut stream = pipe.lock().unwrap();
                 stream.write_all(buf)?;
@@ -72,6 +93,17 @@ impl BufferWriter {
     }
 }
 
+#[cfg(feature = "color")]
+fn adapt(buf: &[u8], _write_style: WriteStyle) -> std::io::Result<Vec<u8>> {
+    use std::io::Write as _;
+
+    let adapted = Vec::with_capacity(buf.len());
+    let mut stream = anstream::StripStream::new(adapted);
+    stream.write_all(buf)?;
+    let adapted = stream.into_inner();
+    Ok(adapted)
+}
+
 pub(in crate::fmt) struct Buffer(Vec<u8>);
 
 impl Buffer {
diff --git a/src/fmt/writer/mod.rs b/src/fmt/writer/mod.rs
index f5f7de32..65f3445e 100644
--- a/src/fmt/writer/mod.rs
+++ b/src/fmt/writer/mod.rs
@@ -1,8 +1,6 @@
-mod atty;
 mod buffer;
 mod target;
 
-use self::atty::{is_stderr, is_stdout};
 use self::buffer::BufferWriter;
 use std::{fmt, io, mem, sync::Mutex};
 
@@ -11,8 +9,7 @@ pub(super) use self::buffer::Buffer;
 pub use target::Target;
 
 /// Whether or not to print styles to the target.
-#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
-#[derive(Default)]
+#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq, Default)]
 pub enum WriteStyle {
     /// Try to print styles, but don't force the issue.
     #[default]
@@ -23,7 +20,28 @@ pub enum WriteStyle {
     Never,
 }
 
+#[cfg(feature = "color")]
+impl From<anstream::ColorChoice> for WriteStyle {
+    fn from(choice: anstream::ColorChoice) -> Self {
+        match choice {
+            anstream::ColorChoice::Auto => Self::Auto,
+            anstream::ColorChoice::Always => Self::Always,
+            anstream::ColorChoice::AlwaysAnsi => Self::Always,
+            anstream::ColorChoice::Never => Self::Never,
+        }
+    }
+}
 
+#[cfg(feature = "color")]
+impl From<WriteStyle> for anstream::ColorChoice {
+    fn from(choice: WriteStyle) -> Self {
+        match choice {
+            WriteStyle::Auto => anstream::ColorChoice::Auto,
+            WriteStyle::Always => anstream::ColorChoice::Always,
+            WriteStyle::Never => anstream::ColorChoice::Never,
+        }
+    }
+}
 
 /// A terminal target with color awareness.
 pub(crate) struct Writer {
@@ -105,29 +123,36 @@ impl Builder {
         assert!(!self.built, "attempt to re-use consumed builder");
         self.built = true;
 
-        let color_choice = match self.write_style {
-            WriteStyle::Auto => {
-                if match &self.target {
-                    Target::Stderr => is_stderr(),
-                    Target::Stdout => is_stdout(),
-                    Target::Pipe(_) => false,
-                } {
-                    WriteStyle::Auto
-                } else {
-                    WriteStyle::Never
-                }
+        let color_choice = self.write_style;
+        #[cfg(feature = "auto-color")]
+        let color_choice = if color_choice == WriteStyle::Auto {
+            match &self.target {
+                Target::Stdout => anstream::AutoStream::choice(&std::io::stdout()).into(),
+                Target::Stderr => anstream::AutoStream::choice(&std::io::stderr()).into(),
+                Target::Pipe(_) => WriteStyle::Never,
             }
-            color_choice => color_choice,
+        } else {
+            color_choice
+        };
+        let color_choice = match &self.target {
+            Target::Stdout => color_choice,
+            Target::Stderr => color_choice,
+            Target::Pipe(_) => WriteStyle::Never,
         };
         let color_choice = if self.is_test {
             WriteStyle::Never
         } else {
             color_choice
         };
+        let color_choice = if color_choice == WriteStyle::Auto {
+            WriteStyle::Never
+        } else {
+            color_choice
+        };
 
         let writer = match mem::take(&mut self.target) {
-            Target::Stderr => BufferWriter::stderr(self.is_test, color_choice),
             Target::Stdout => BufferWriter::stdout(self.is_test, color_choice),
+            Target::Stderr => BufferWriter::stderr(self.is_test, color_choice),
             Target::Pipe(pipe) => BufferWriter::pipe(Box::new(Mutex::new(pipe))),
         };
 
diff --git a/src/logger.rs b/src/logger.rs
index 6c8a00d4..1e7d5894 100644
--- a/src/logger.rs
+++ b/src/logger.rs
@@ -223,6 +223,9 @@ impl Builder {
     /// to format and output without intermediate heap allocations. The default
     /// `env_logger` formatter takes advantage of this.
     ///
+    /// When the `color` feature is enabled, styling via ANSI escape codes is supported and the
+    /// output will automatically respect [`Builder::write_style`].
+    ///
     /// # Examples
     ///
     /// Use a custom format to write only the log message:

From 7d5b72a76e62616a4d3328bde084a95af052ba8b Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Thu, 18 Jan 2024 10:29:49 -0600
Subject: [PATCH 10/28] feat(fmt): Add back in Formatter::default_level_style

---
 Cargo.lock     |  1 +
 Cargo.toml     |  3 ++-
 src/fmt/mod.rs | 27 +++++++++++++++++++++++++++
 3 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/Cargo.lock b/Cargo.lock
index ac42c663..69452d28 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -76,6 +76,7 @@ name = "env_logger"
 version = "0.10.2"
 dependencies = [
  "anstream",
+ "anstyle",
  "humantime",
  "log",
  "regex",
diff --git a/Cargo.toml b/Cargo.toml
index 06871c62..a4ccec85 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -38,7 +38,7 @@ pre-release-replacements = [
 
 [features]
 default = ["auto-color", "humantime", "regex"]
-color = ["dep:anstream"]
+color = ["dep:anstream", "dep:anstyle"]
 auto-color = ["color", "anstream/auto"]
 humantime = ["dep:humantime"]
 regex = ["dep:regex"]
@@ -48,6 +48,7 @@ log = { version = "0.4.8", features = ["std"] }
 regex = { version = "1.0.3", optional = true, default-features=false, features=["std", "perf"] }
 humantime = { version = "2.0.0", optional = true }
 anstream = { version = "0.6.11", default-features = false, features = ["wincon"], optional = true }
+anstyle = { version = "1.0.4", optional = true }
 
 [[test]]
 name = "regexp_filter"
diff --git a/src/fmt/mod.rs b/src/fmt/mod.rs
index dd78402f..bc5e6134 100644
--- a/src/fmt/mod.rs
+++ b/src/fmt/mod.rs
@@ -35,12 +35,17 @@ use std::io::prelude::*;
 use std::rc::Rc;
 use std::{fmt, io, mem};
 
+#[cfg(feature = "color")]
+use log::Level;
 use log::Record;
 
 #[cfg(feature = "humantime")]
 mod humantime;
 pub(crate) mod writer;
 
+#[cfg(feature = "color")]
+pub use anstyle as style;
+
 #[cfg(feature = "humantime")]
 pub use self::humantime::Timestamp;
 pub use self::writer::Target;
@@ -119,6 +124,28 @@ impl Formatter {
     }
 }
 
+#[cfg(feature = "color")]
+impl Formatter {
+    /// Get the default [`style::Style`] for the given level.
+    ///
+    /// The style can be used to print other values besides the level.
+    pub fn default_level_style(&self, level: Level) -> style::Style {
+        if self.write_style == WriteStyle::Never {
+            style::Style::new()
+        } else {
+            match level {
+                Level::Trace => style::AnsiColor::Cyan.on_default(),
+                Level::Debug => style::AnsiColor::Blue.on_default(),
+                Level::Info => style::AnsiColor::Green.on_default(),
+                Level::Warn => style::AnsiColor::Yellow.on_default(),
+                Level::Error => style::AnsiColor::Red
+                    .on_default()
+                    .effects(style::Effects::BOLD),
+            }
+        }
+    }
+}
+
 impl Write for Formatter {
     fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
         self.buf.borrow_mut().write(buf)

From 2f3ca7d6956fa014927bf1a7316e6981e3829309 Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Thu, 18 Jan 2024 10:36:03 -0600
Subject: [PATCH 11/28] docs: Add back in custom colors

---
 examples/custom_format.rs | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/examples/custom_format.rs b/examples/custom_format.rs
index 1cc4bdec..8f575fd4 100644
--- a/examples/custom_format.rs
+++ b/examples/custom_format.rs
@@ -30,9 +30,18 @@ fn main() {
 
         Builder::from_env(env)
             .format(|buf, record| {
+                // We are reusing `anstyle` but there are `anstyle-*` crates to adapt it to your
+                // preferred styling crate.
+                let warn_style = buf.default_level_style(log::Level::Warn);
+                let reset = warn_style.render_reset();
+                let warn_style = warn_style.render();
                 let timestamp = buf.timestamp();
 
-                writeln!(buf, "My formatted log ({}): {}", timestamp, record.args())
+                writeln!(
+                    buf,
+                    "My formatted log ({timestamp}): {warn_style}{}{reset}",
+                    record.args()
+                )
             })
             .init();
     }

From 303a9c0ed288c5c7c15b6a74e29bfc1467bf9eab Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Thu, 18 Jan 2024 10:56:55 -0600
Subject: [PATCH 12/28] feat(fmt): Add back in level styling

---
 src/fmt/mod.rs | 52 +++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 51 insertions(+), 1 deletion(-)

diff --git a/src/fmt/mod.rs b/src/fmt/mod.rs
index bc5e6134..771fd5cd 100644
--- a/src/fmt/mod.rs
+++ b/src/fmt/mod.rs
@@ -228,8 +228,37 @@ impl Default for Builder {
     }
 }
 
+#[cfg(feature = "color")]
+type SubtleStyle = StyledValue<&'static str>;
+#[cfg(not(feature = "color"))]
 type SubtleStyle = &'static str;
 
+/// A value that can be printed using the given styles.
+///
+/// It is the result of calling [`Style::value`].
+///
+/// [`Style::value`]: struct.Style.html#method.value
+#[cfg(feature = "color")]
+struct StyledValue<T> {
+    style: style::Style,
+    value: T,
+}
+
+#[cfg(feature = "color")]
+impl<T: std::fmt::Display> std::fmt::Display for StyledValue<T> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let style = self.style.render();
+        let reset = self.style.render_reset();
+
+        // We need to make sure `f`s settings don't get passed onto the styling but do get passed
+        // to the value
+        write!(f, "{style}")?;
+        self.value.fmt(f)?;
+        write!(f, "{reset}")?;
+        Ok(())
+    }
+}
+
 /// The default format.
 ///
 /// This format needs to work with any combination of crate features.
@@ -256,6 +285,18 @@ impl<'a> DefaultFormat<'a> {
     }
 
     fn subtle_style(&self, text: &'static str) -> SubtleStyle {
+        #[cfg(feature = "color")]
+        {
+            StyledValue {
+                style: if self.buf.write_style == WriteStyle::Never {
+                    style::Style::new()
+                } else {
+                    style::AnsiColor::BrightBlack.on_default()
+                },
+                value: text,
+            }
+        }
+        #[cfg(not(feature = "color"))]
         {
             text
         }
@@ -281,8 +322,17 @@ impl<'a> DefaultFormat<'a> {
         }
 
         let level = {
+            let level = record.level();
+            #[cfg(feature = "color")]
+            {
+                StyledValue {
+                    style: self.buf.default_level_style(level),
+                    value: level,
+                }
+            }
+            #[cfg(not(feature = "color"))]
             {
-                record.level()
+                level
             }
         };
 

From 4276f5fa7efc08408e1c2f6dcd9cc8b042afd6c1 Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Thu, 18 Jan 2024 11:14:10 -0600
Subject: [PATCH 13/28] fix(fmt): Print colors for tests

This was discussed in #225 but no dedicated issue for it.
---
 src/fmt/writer/buffer.rs | 4 ++--
 src/fmt/writer/mod.rs    | 5 -----
 2 files changed, 2 insertions(+), 7 deletions(-)

diff --git a/src/fmt/writer/buffer.rs b/src/fmt/writer/buffer.rs
index aeffde05..fe983a00 100644
--- a/src/fmt/writer/buffer.rs
+++ b/src/fmt/writer/buffer.rs
@@ -94,11 +94,11 @@ impl BufferWriter {
 }
 
 #[cfg(feature = "color")]
-fn adapt(buf: &[u8], _write_style: WriteStyle) -> std::io::Result<Vec<u8>> {
+fn adapt(buf: &[u8], write_style: WriteStyle) -> std::io::Result<Vec<u8>> {
     use std::io::Write as _;
 
     let adapted = Vec::with_capacity(buf.len());
-    let mut stream = anstream::StripStream::new(adapted);
+    let mut stream = anstream::AutoStream::new(adapted, write_style.into());
     stream.write_all(buf)?;
     let adapted = stream.into_inner();
     Ok(adapted)
diff --git a/src/fmt/writer/mod.rs b/src/fmt/writer/mod.rs
index 65f3445e..545d642d 100644
--- a/src/fmt/writer/mod.rs
+++ b/src/fmt/writer/mod.rs
@@ -139,11 +139,6 @@ impl Builder {
             Target::Stderr => color_choice,
             Target::Pipe(_) => WriteStyle::Never,
         };
-        let color_choice = if self.is_test {
-            WriteStyle::Never
-        } else {
-            color_choice
-        };
         let color_choice = if color_choice == WriteStyle::Auto {
             WriteStyle::Never
         } else {

From 730b0a096b121e4732f9e69a0132f1ccd4dbd9ed Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Thu, 18 Jan 2024 11:15:32 -0600
Subject: [PATCH 14/28] fix(fmt): Allow styling on the `Pipe`

Fixes #274
---
 src/fmt/writer/buffer.rs | 4 ++++
 src/fmt/writer/mod.rs    | 7 +------
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/src/fmt/writer/buffer.rs b/src/fmt/writer/buffer.rs
index fe983a00..89ad9125 100644
--- a/src/fmt/writer/buffer.rs
+++ b/src/fmt/writer/buffer.rs
@@ -83,6 +83,10 @@ impl BufferWriter {
                 eprint!("{}", buf);
             }
             WritableTarget::Pipe(pipe) => {
+                #[cfg(feature = "color")]
+                let buf = adapt(buf, self.write_style)?;
+                #[cfg(feature = "color")]
+                let buf = &buf;
                 let mut stream = pipe.lock().unwrap();
                 stream.write_all(buf)?;
                 stream.flush()?;
diff --git a/src/fmt/writer/mod.rs b/src/fmt/writer/mod.rs
index 545d642d..a3e66065 100644
--- a/src/fmt/writer/mod.rs
+++ b/src/fmt/writer/mod.rs
@@ -129,16 +129,11 @@ impl Builder {
             match &self.target {
                 Target::Stdout => anstream::AutoStream::choice(&std::io::stdout()).into(),
                 Target::Stderr => anstream::AutoStream::choice(&std::io::stderr()).into(),
-                Target::Pipe(_) => WriteStyle::Never,
+                Target::Pipe(_) => color_choice,
             }
         } else {
             color_choice
         };
-        let color_choice = match &self.target {
-            Target::Stdout => color_choice,
-            Target::Stderr => color_choice,
-            Target::Pipe(_) => WriteStyle::Never,
-        };
         let color_choice = if color_choice == WriteStyle::Auto {
             WriteStyle::Never
         } else {

From ea464099b79fd5038d77e318bb46237868473b3d Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Thu, 18 Jan 2024 12:21:39 -0600
Subject: [PATCH 15/28] chore(fmt): Add debug impls

---
 src/fmt/mod.rs           | 6 +++++-
 src/fmt/writer/buffer.rs | 7 +++++++
 src/fmt/writer/mod.rs    | 9 ++-------
 3 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/src/fmt/mod.rs b/src/fmt/mod.rs
index 771fd5cd..faee69bb 100644
--- a/src/fmt/mod.rs
+++ b/src/fmt/mod.rs
@@ -158,7 +158,11 @@ impl Write for Formatter {
 
 impl fmt::Debug for Formatter {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        f.debug_struct("Formatter").finish()
+        let buf = self.buf.borrow();
+        f.debug_struct("Formatter")
+            .field("buf", &buf)
+            .field("write_style", &self.write_style)
+            .finish()
     }
 }
 
diff --git a/src/fmt/writer/buffer.rs b/src/fmt/writer/buffer.rs
index 89ad9125..a7ea25bf 100644
--- a/src/fmt/writer/buffer.rs
+++ b/src/fmt/writer/buffer.rs
@@ -2,6 +2,7 @@ use std::{io, sync::Mutex};
 
 use crate::fmt::writer::WriteStyle;
 
+#[derive(Debug)]
 pub(in crate::fmt::writer) struct BufferWriter {
     target: WritableTarget,
     write_style: WriteStyle,
@@ -129,6 +130,12 @@ impl Buffer {
     }
 }
 
+impl std::fmt::Debug for Buffer {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        String::from_utf8_lossy(self.as_bytes()).fmt(f)
+    }
+}
+
 /// Log target, either `stdout`, `stderr` or a custom pipe.
 ///
 /// Same as `Target`, except the pipe is wrapped in a mutex for interior mutability.
diff --git a/src/fmt/writer/mod.rs b/src/fmt/writer/mod.rs
index a3e66065..dbcf45b6 100644
--- a/src/fmt/writer/mod.rs
+++ b/src/fmt/writer/mod.rs
@@ -2,7 +2,7 @@ mod buffer;
 mod target;
 
 use self::buffer::BufferWriter;
-use std::{fmt, io, mem, sync::Mutex};
+use std::{io, mem, sync::Mutex};
 
 pub(super) use self::buffer::Buffer;
 
@@ -44,6 +44,7 @@ impl From<WriteStyle> for anstream::ColorChoice {
 }
 
 /// A terminal target with color awareness.
+#[derive(Debug)]
 pub(crate) struct Writer {
     inner: BufferWriter,
 }
@@ -62,12 +63,6 @@ impl Writer {
     }
 }
 
-impl fmt::Debug for Writer {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        f.debug_struct("Writer").finish()
-    }
-}
-
 /// A builder for a terminal writer.
 ///
 /// The target and style choice can be configured before building.

From b4a2c304c16d1db4a2998f24c00e00c0f776113b Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Fri, 19 Jan 2024 10:56:23 -0600
Subject: [PATCH 16/28] chore: Add a workspace

---
 Cargo.toml | 29 +++++++++++++++++++----------
 1 file changed, 19 insertions(+), 10 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index a4ccec85..9c17f7c7 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,13 +1,7 @@
-[package]
-name = "env_logger"
-version = "0.10.2"
-description = """
-A logging implementation for `log` which is configured via an environment
-variable.
-"""
-repository = "https://github.com/rust-cli/env_logger"
-categories = ["development-tools::debugging"]
-keywords = ["logging", "log", "logger"]
+[workspace]
+resolver = "2"
+
+[workspace.package]
 license = "MIT OR Apache-2.0"
 edition = "2021"
 rust-version = "1.71"  # MSRV
@@ -23,6 +17,21 @@ include = [
   "tests/**/*",
 ]
 
+[package]
+name = "env_logger"
+version = "0.10.2"
+description = """
+A logging implementation for `log` which is configured via an environment
+variable.
+"""
+repository = "https://github.com/rust-cli/env_logger"
+categories = ["development-tools::debugging"]
+keywords = ["logging", "log", "logger"]
+license.workspace = true
+edition.workspace = true
+rust-version.workspace = true
+include.workspace = true
+
 [package.metadata.docs.rs]
 all-features = true
 rustdoc-args = ["--cfg", "docsrs"]

From f1877824da51e8b79bcd8747e168b610b4a64cb3 Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Fri, 19 Jan 2024 11:12:17 -0600
Subject: [PATCH 17/28] refactor: Split out env_filter package

Fixes #193
---
 Cargo.lock                                    | 10 +++++-
 Cargo.toml                                    |  5 +--
 crates/env_filter/CHANGELOG.md                | 11 ++++++
 crates/env_filter/Cargo.toml                  | 34 +++++++++++++++++++
 crates/env_filter/LICENSE-APACHE              |  1 +
 crates/env_filter/LICENSE-MIT                 |  1 +
 crates/env_filter/README.md                   |  6 ++++
 .../mod.rs => crates/env_filter/src/lib.rs    | 27 +++++----------
 .../filter => crates/env_filter/src}/regex.rs |  4 +--
 .../env_filter/src}/string.rs                 |  0
 src/lib.rs                                    |  3 +-
 11 files changed, 76 insertions(+), 26 deletions(-)
 create mode 100644 crates/env_filter/CHANGELOG.md
 create mode 100644 crates/env_filter/Cargo.toml
 create mode 120000 crates/env_filter/LICENSE-APACHE
 create mode 120000 crates/env_filter/LICENSE-MIT
 create mode 100644 crates/env_filter/README.md
 rename src/filter/mod.rs => crates/env_filter/src/lib.rs (97%)
 rename {src/filter => crates/env_filter/src}/regex.rs (91%)
 rename {src/filter => crates/env_filter/src}/string.rs (100%)

diff --git a/Cargo.lock b/Cargo.lock
index 69452d28..776d3400 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -71,15 +71,23 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "acbf1af155f9b9ef647e42cdc158db4b64a1b61f743629225fde6f3e0be2a7c7"
 
+[[package]]
+name = "env_filter"
+version = "0.1.0"
+dependencies = [
+ "log",
+ "regex",
+]
+
 [[package]]
 name = "env_logger"
 version = "0.10.2"
 dependencies = [
  "anstream",
  "anstyle",
+ "env_filter",
  "humantime",
  "log",
- "regex",
 ]
 
 [[package]]
diff --git a/Cargo.toml b/Cargo.toml
index 9c17f7c7..b669cef6 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,5 +1,6 @@
 [workspace]
 resolver = "2"
+members = ["crates/*"]
 
 [workspace.package]
 license = "MIT OR Apache-2.0"
@@ -50,11 +51,11 @@ default = ["auto-color", "humantime", "regex"]
 color = ["dep:anstream", "dep:anstyle"]
 auto-color = ["color", "anstream/auto"]
 humantime = ["dep:humantime"]
-regex = ["dep:regex"]
+regex = ["env_filter/regex"]
 
 [dependencies]
 log = { version = "0.4.8", features = ["std"] }
-regex = { version = "1.0.3", optional = true, default-features=false, features=["std", "perf"] }
+env_filter = { version = "0.1.0", path = "crates/env_filter", default-features = false }
 humantime = { version = "2.0.0", optional = true }
 anstream = { version = "0.6.11", default-features = false, features = ["wincon"], optional = true }
 anstyle = { version = "1.0.4", optional = true }
diff --git a/crates/env_filter/CHANGELOG.md b/crates/env_filter/CHANGELOG.md
new file mode 100644
index 00000000..78e2e120
--- /dev/null
+++ b/crates/env_filter/CHANGELOG.md
@@ -0,0 +1,11 @@
+# Change Log
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](http://keepachangelog.com/)
+and this project adheres to [Semantic Versioning](http://semver.org/).
+
+<!-- next-header -->
+## [Unreleased] - ReleaseDate
+
+<!-- next-url -->
+[Unreleased]: https://github.com/rust-cli/env_logger/compare/b4a2c304c16d1db4a2998f24c00e00c0f776113b...HEAD
diff --git a/crates/env_filter/Cargo.toml b/crates/env_filter/Cargo.toml
new file mode 100644
index 00000000..9ac0fa47
--- /dev/null
+++ b/crates/env_filter/Cargo.toml
@@ -0,0 +1,34 @@
+[package]
+name = "env_filter"
+version = "0.1.0"
+description = """
+Filter log events using environment variables
+"""
+repository = "https://github.com/rust-cli/env_logger"
+categories = ["development-tools::debugging"]
+keywords = ["logging", "log", "logger"]
+license.workspace = true
+edition.workspace = true
+rust-version.workspace = true
+include.workspace = true
+
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs"]
+
+[package.metadata.release]
+pre-release-replacements = [
+  {file="CHANGELOG.md", search="Unreleased", replace="{{version}}", min=1},
+  {file="CHANGELOG.md", search="\\.\\.\\.HEAD", replace="...{{tag_name}}", exactly=1},
+  {file="CHANGELOG.md", search="ReleaseDate", replace="{{date}}", min=1},
+  {file="CHANGELOG.md", search="<!-- next-header -->", replace="<!-- next-header -->\n## [Unreleased] - ReleaseDate\n", exactly=1},
+  {file="CHANGELOG.md", search="<!-- next-url -->", replace="<!-- next-url -->\n[Unreleased]: https://github.com/rust-cli/env_logger/compare/{{tag_name}}...HEAD", exactly=1},
+]
+
+[features]
+default = ["regex"]
+regex = ["dep:regex"]
+
+[dependencies]
+log = { version = "0.4.8", features = ["std"] }
+regex = { version = "1.0.3", optional = true, default-features=false, features=["std", "perf"] }
diff --git a/crates/env_filter/LICENSE-APACHE b/crates/env_filter/LICENSE-APACHE
new file mode 120000
index 00000000..1cd601d0
--- /dev/null
+++ b/crates/env_filter/LICENSE-APACHE
@@ -0,0 +1 @@
+../../LICENSE-APACHE
\ No newline at end of file
diff --git a/crates/env_filter/LICENSE-MIT b/crates/env_filter/LICENSE-MIT
new file mode 120000
index 00000000..b2cfbdc7
--- /dev/null
+++ b/crates/env_filter/LICENSE-MIT
@@ -0,0 +1 @@
+../../LICENSE-MIT
\ No newline at end of file
diff --git a/crates/env_filter/README.md b/crates/env_filter/README.md
new file mode 100644
index 00000000..9e5164fb
--- /dev/null
+++ b/crates/env_filter/README.md
@@ -0,0 +1,6 @@
+# env_filter
+
+[![crates.io](https://img.shields.io/crates/v/env_filter.svg)](https://crates.io/crates/env_filter)
+[![Documentation](https://docs.rs/env_filter/badge.svg)](https://docs.rs/env_filter)
+
+> Filter log events using environment variables
diff --git a/src/filter/mod.rs b/crates/env_filter/src/lib.rs
similarity index 97%
rename from src/filter/mod.rs
rename to crates/env_filter/src/lib.rs
index d4acf632..5d7d60b0 100644
--- a/src/filter/mod.rs
+++ b/crates/env_filter/src/lib.rs
@@ -1,21 +1,17 @@
 //! Filtering for log records.
 //!
-//! This module contains the log filtering used by `env_logger` to match records.
-//! You can use the `Filter` type in your own logger implementation to use the same
-//! filter parsing and matching as `env_logger`. For more details about the format
-//! for directive strings see [Enabling Logging].
+//! You can use the [`Filter`] type in your own logger implementation to use the same
+//! filter parsing and matching as `env_logger`.
 //!
-//! ## Using `env_logger` in your own logger
+//! ## Using `env_filter` in your own logger
 //!
-//! You can use `env_logger`'s filtering functionality with your own logger.
+//! You can use `env_filter`'s filtering functionality with your own logger.
 //! Call [`Builder::parse`] to parse directives from a string when constructing
 //! your logger. Call [`Filter::matches`] to check whether a record should be
 //! logged based on the parsed filters when log records are received.
 //!
 //! ```
-//! extern crate log;
-//! extern crate env_logger;
-//! use env_logger::filter::Filter;
+//! use env_filter::Filter;
 //! use log::{Log, Metadata, Record};
 //!
 //! struct MyLogger {
@@ -24,7 +20,7 @@
 //!
 //! impl MyLogger {
 //!     fn new() -> MyLogger {
-//!         use env_logger::filter::Builder;
+//!         use env_filter::Builder;
 //!         let mut builder = Builder::new();
 //!
 //!         // Parse a directives string from an environment variable
@@ -53,10 +49,6 @@
 //!     fn flush(&self) {}
 //! }
 //! ```
-//!
-//! [Enabling Logging]: ../index.html#enabling-logging
-//! [`Builder::parse`]: struct.Builder.html#method.parse
-//! [`Filter::matches`]: struct.Filter.html#method.matches
 
 use log::{Level, LevelFilter, Metadata, Record};
 use std::env;
@@ -79,9 +71,8 @@ mod inner;
 /// ## Example
 ///
 /// ```
-/// # #[macro_use] extern crate log;
 /// # use std::env;
-/// use env_logger::filter::Builder;
+/// use env_filter::Builder;
 ///
 /// let mut builder = Builder::new();
 ///
@@ -92,8 +83,6 @@ mod inner;
 ///
 /// let filter = builder.build();
 /// ```
-///
-/// [`Filter`]: struct.Filter.html
 pub struct Builder {
     directives: Vec<Directive>,
     filter: Option<inner::Filter>,
@@ -248,7 +237,7 @@ impl Filter {
     ///
     /// ```rust
     /// use log::LevelFilter;
-    /// use env_logger::filter::Builder;
+    /// use env_filter::Builder;
     ///
     /// let mut builder = Builder::new();
     /// builder.filter(Some("module1"), LevelFilter::Info);
diff --git a/src/filter/regex.rs b/crates/env_filter/src/regex.rs
similarity index 91%
rename from src/filter/regex.rs
rename to crates/env_filter/src/regex.rs
index fb21528a..d56355af 100644
--- a/src/filter/regex.rs
+++ b/crates/env_filter/src/regex.rs
@@ -1,8 +1,6 @@
-extern crate regex;
-
 use std::fmt;
 
-use self::regex::Regex;
+use regex::Regex;
 
 #[derive(Debug)]
 pub struct Filter {
diff --git a/src/filter/string.rs b/crates/env_filter/src/string.rs
similarity index 100%
rename from src/filter/string.rs
rename to crates/env_filter/src/string.rs
diff --git a/src/lib.rs b/src/lib.rs
index 93eba6ce..76cbf3a5 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -277,7 +277,8 @@
 
 mod logger;
 
-pub mod filter;
+#[doc(inline)]
+pub use ::env_filter as filter;
 pub mod fmt;
 
 pub use self::fmt::{Target, TimestampPrecision, WriteStyle};

From 57d938c7c75f07f927e8969a8013c65873f8fce0 Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Fri, 19 Jan 2024 11:28:41 -0600
Subject: [PATCH 18/28] refactor(filter): Clean up op mod

---
 crates/env_filter/src/lib.rs    | 16 ++++---------
 crates/env_filter/src/op.rs     | 42 +++++++++++++++++++++++++++++++++
 crates/env_filter/src/regex.rs  | 27 ---------------------
 crates/env_filter/src/string.rs | 24 -------------------
 4 files changed, 47 insertions(+), 62 deletions(-)
 create mode 100644 crates/env_filter/src/op.rs
 delete mode 100644 crates/env_filter/src/regex.rs
 delete mode 100644 crates/env_filter/src/string.rs

diff --git a/crates/env_filter/src/lib.rs b/crates/env_filter/src/lib.rs
index 5d7d60b0..609654a4 100644
--- a/crates/env_filter/src/lib.rs
+++ b/crates/env_filter/src/lib.rs
@@ -55,13 +55,7 @@ use std::env;
 use std::fmt;
 use std::mem;
 
-#[cfg(feature = "regex")]
-#[path = "regex.rs"]
-mod inner;
-
-#[cfg(not(feature = "regex"))]
-#[path = "string.rs"]
-mod inner;
+mod op;
 
 /// A builder for a log filter.
 ///
@@ -85,7 +79,7 @@ mod inner;
 /// ```
 pub struct Builder {
     directives: Vec<Directive>,
-    filter: Option<inner::Filter>,
+    filter: Option<op::FilterOp>,
     built: bool,
 }
 
@@ -226,7 +220,7 @@ struct Directive {
 /// [`Builder`]: struct.Builder.html
 pub struct Filter {
     directives: Vec<Directive>,
-    filter: Option<inner::Filter>,
+    filter: Option<op::FilterOp>,
 }
 
 impl Filter {
@@ -289,7 +283,7 @@ impl fmt::Debug for Filter {
 
 /// Parse a logging specification string (e.g: "crate1,crate2::mod3,crate3::x=error/foo")
 /// and return a vector with log directives.
-fn parse_spec(spec: &str) -> (Vec<Directive>, Option<inner::Filter>) {
+fn parse_spec(spec: &str) -> (Vec<Directive>, Option<op::FilterOp>) {
     let mut dirs = Vec::new();
 
     let mut parts = spec.split('/');
@@ -347,7 +341,7 @@ fn parse_spec(spec: &str) -> (Vec<Directive>, Option<inner::Filter>) {
         }
     }
 
-    let filter = filter.and_then(|filter| match inner::Filter::new(filter) {
+    let filter = filter.and_then(|filter| match op::FilterOp::new(filter) {
         Ok(re) => Some(re),
         Err(e) => {
             eprintln!("warning: invalid regex filter - {}", e);
diff --git a/crates/env_filter/src/op.rs b/crates/env_filter/src/op.rs
new file mode 100644
index 00000000..e018e540
--- /dev/null
+++ b/crates/env_filter/src/op.rs
@@ -0,0 +1,42 @@
+use std::fmt;
+
+#[derive(Debug)]
+pub struct FilterOp {
+    #[cfg(feature = "regex")]
+    inner: regex::Regex,
+    #[cfg(not(feature = "regex"))]
+    inner: String,
+}
+
+#[cfg(feature = "regex")]
+impl FilterOp {
+    pub fn new(spec: &str) -> Result<Self, String> {
+        match regex::Regex::new(spec) {
+            Ok(r) => Ok(Self { inner: r }),
+            Err(e) => Err(e.to_string()),
+        }
+    }
+
+    pub fn is_match(&self, s: &str) -> bool {
+        self.inner.is_match(s)
+    }
+}
+
+#[cfg(not(feature = "regex"))]
+impl FilterOp {
+    pub fn new(spec: &str) -> Result<Self, String> {
+        Ok(Self {
+            inner: spec.to_string(),
+        })
+    }
+
+    pub fn is_match(&self, s: &str) -> bool {
+        s.contains(&self.inner)
+    }
+}
+
+impl fmt::Display for FilterOp {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        self.inner.fmt(f)
+    }
+}
diff --git a/crates/env_filter/src/regex.rs b/crates/env_filter/src/regex.rs
deleted file mode 100644
index d56355af..00000000
--- a/crates/env_filter/src/regex.rs
+++ /dev/null
@@ -1,27 +0,0 @@
-use std::fmt;
-
-use regex::Regex;
-
-#[derive(Debug)]
-pub struct Filter {
-    inner: Regex,
-}
-
-impl Filter {
-    pub fn new(spec: &str) -> Result<Filter, String> {
-        match Regex::new(spec) {
-            Ok(r) => Ok(Filter { inner: r }),
-            Err(e) => Err(e.to_string()),
-        }
-    }
-
-    pub fn is_match(&self, s: &str) -> bool {
-        self.inner.is_match(s)
-    }
-}
-
-impl fmt::Display for Filter {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        self.inner.fmt(f)
-    }
-}
diff --git a/crates/env_filter/src/string.rs b/crates/env_filter/src/string.rs
deleted file mode 100644
index ea476e42..00000000
--- a/crates/env_filter/src/string.rs
+++ /dev/null
@@ -1,24 +0,0 @@
-use std::fmt;
-
-#[derive(Debug)]
-pub struct Filter {
-    inner: String,
-}
-
-impl Filter {
-    pub fn new(spec: &str) -> Result<Filter, String> {
-        Ok(Filter {
-            inner: spec.to_string(),
-        })
-    }
-
-    pub fn is_match(&self, s: &str) -> bool {
-        s.contains(&self.inner)
-    }
-}
-
-impl fmt::Display for Filter {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        self.inner.fmt(f)
-    }
-}

From 3b45c6ffc11d0952dc67ebc9aadf8a990905d44b Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Fri, 19 Jan 2024 11:32:01 -0600
Subject: [PATCH 19/28] refactor(filter): Pull out parser mod

---
 crates/env_filter/src/lib.rs    | 255 +------------------------------
 crates/env_filter/src/parser.rs | 261 ++++++++++++++++++++++++++++++++
 2 files changed, 264 insertions(+), 252 deletions(-)
 create mode 100644 crates/env_filter/src/parser.rs

diff --git a/crates/env_filter/src/lib.rs b/crates/env_filter/src/lib.rs
index 609654a4..a90342e7 100644
--- a/crates/env_filter/src/lib.rs
+++ b/crates/env_filter/src/lib.rs
@@ -56,6 +56,7 @@ use std::fmt;
 use std::mem;
 
 mod op;
+mod parser;
 
 /// A builder for a log filter.
 ///
@@ -145,7 +146,7 @@ impl Builder {
     ///
     /// [Enabling Logging]: ../index.html#enabling-logging
     pub fn parse(&mut self, filters: &str) -> &mut Self {
-        let (directives, filter) = parse_spec(filters);
+        let (directives, filter) = parser::parse_spec(filters);
 
         self.filter = filter;
 
@@ -281,77 +282,6 @@ impl fmt::Debug for Filter {
     }
 }
 
-/// Parse a logging specification string (e.g: "crate1,crate2::mod3,crate3::x=error/foo")
-/// and return a vector with log directives.
-fn parse_spec(spec: &str) -> (Vec<Directive>, Option<op::FilterOp>) {
-    let mut dirs = Vec::new();
-
-    let mut parts = spec.split('/');
-    let mods = parts.next();
-    let filter = parts.next();
-    if parts.next().is_some() {
-        eprintln!(
-            "warning: invalid logging spec '{}', \
-             ignoring it (too many '/'s)",
-            spec
-        );
-        return (dirs, None);
-    }
-    if let Some(m) = mods {
-        for s in m.split(',').map(|ss| ss.trim()) {
-            if s.is_empty() {
-                continue;
-            }
-            let mut parts = s.split('=');
-            let (log_level, name) =
-                match (parts.next(), parts.next().map(|s| s.trim()), parts.next()) {
-                    (Some(part0), None, None) => {
-                        // if the single argument is a log-level string or number,
-                        // treat that as a global fallback
-                        match part0.parse() {
-                            Ok(num) => (num, None),
-                            Err(_) => (LevelFilter::max(), Some(part0)),
-                        }
-                    }
-                    (Some(part0), Some(""), None) => (LevelFilter::max(), Some(part0)),
-                    (Some(part0), Some(part1), None) => match part1.parse() {
-                        Ok(num) => (num, Some(part0)),
-                        _ => {
-                            eprintln!(
-                                "warning: invalid logging spec '{}', \
-                                 ignoring it",
-                                part1
-                            );
-                            continue;
-                        }
-                    },
-                    _ => {
-                        eprintln!(
-                            "warning: invalid logging spec '{}', \
-                             ignoring it",
-                            s
-                        );
-                        continue;
-                    }
-                };
-            dirs.push(Directive {
-                name: name.map(|s| s.to_string()),
-                level: log_level,
-            });
-        }
-    }
-
-    let filter = filter.and_then(|filter| match op::FilterOp::new(filter) {
-        Ok(re) => Some(re),
-        Err(e) => {
-            eprintln!("warning: invalid regex filter - {}", e);
-            None
-        }
-    });
-
-    (dirs, filter)
-}
-
 // Check whether a level and target are enabled by the set of directives.
 fn enabled(directives: &[Directive], level: Level, target: &str) -> bool {
     // Search for the longest match, the vector is assumed to be pre-sorted.
@@ -368,7 +298,7 @@ fn enabled(directives: &[Directive], level: Level, target: &str) -> bool {
 mod tests {
     use log::{Level, LevelFilter};
 
-    use super::{enabled, parse_spec, Builder, Directive, Filter};
+    use super::{enabled, Builder, Directive, Filter};
 
     fn make_logger_filter(dirs: Vec<Directive>) -> Filter {
         let mut logger = Builder::new().build();
@@ -680,183 +610,4 @@ mod tests {
         assert!(!enabled(&logger.directives, Level::Error, "crate1::mod1"));
         assert!(enabled(&logger.directives, Level::Info, "crate2::mod2"));
     }
-
-    #[test]
-    fn parse_spec_valid() {
-        let (dirs, filter) = parse_spec("crate1::mod1=error,crate1::mod2,crate2=debug");
-        assert_eq!(dirs.len(), 3);
-        assert_eq!(dirs[0].name, Some("crate1::mod1".to_string()));
-        assert_eq!(dirs[0].level, LevelFilter::Error);
-
-        assert_eq!(dirs[1].name, Some("crate1::mod2".to_string()));
-        assert_eq!(dirs[1].level, LevelFilter::max());
-
-        assert_eq!(dirs[2].name, Some("crate2".to_string()));
-        assert_eq!(dirs[2].level, LevelFilter::Debug);
-        assert!(filter.is_none());
-    }
-
-    #[test]
-    fn parse_spec_invalid_crate() {
-        // test parse_spec with multiple = in specification
-        let (dirs, filter) = parse_spec("crate1::mod1=warn=info,crate2=debug");
-        assert_eq!(dirs.len(), 1);
-        assert_eq!(dirs[0].name, Some("crate2".to_string()));
-        assert_eq!(dirs[0].level, LevelFilter::Debug);
-        assert!(filter.is_none());
-    }
-
-    #[test]
-    fn parse_spec_invalid_level() {
-        // test parse_spec with 'noNumber' as log level
-        let (dirs, filter) = parse_spec("crate1::mod1=noNumber,crate2=debug");
-        assert_eq!(dirs.len(), 1);
-        assert_eq!(dirs[0].name, Some("crate2".to_string()));
-        assert_eq!(dirs[0].level, LevelFilter::Debug);
-        assert!(filter.is_none());
-    }
-
-    #[test]
-    fn parse_spec_string_level() {
-        // test parse_spec with 'warn' as log level
-        let (dirs, filter) = parse_spec("crate1::mod1=wrong,crate2=warn");
-        assert_eq!(dirs.len(), 1);
-        assert_eq!(dirs[0].name, Some("crate2".to_string()));
-        assert_eq!(dirs[0].level, LevelFilter::Warn);
-        assert!(filter.is_none());
-    }
-
-    #[test]
-    fn parse_spec_empty_level() {
-        // test parse_spec with '' as log level
-        let (dirs, filter) = parse_spec("crate1::mod1=wrong,crate2=");
-        assert_eq!(dirs.len(), 1);
-        assert_eq!(dirs[0].name, Some("crate2".to_string()));
-        assert_eq!(dirs[0].level, LevelFilter::max());
-        assert!(filter.is_none());
-    }
-
-    #[test]
-    fn parse_spec_empty_level_isolated() {
-        // test parse_spec with "" as log level (and the entire spec str)
-        let (dirs, filter) = parse_spec(""); // should be ignored
-        assert_eq!(dirs.len(), 0);
-        assert!(filter.is_none());
-    }
-
-    #[test]
-    fn parse_spec_blank_level_isolated() {
-        // test parse_spec with a white-space-only string specified as the log
-        // level (and the entire spec str)
-        let (dirs, filter) = parse_spec("     "); // should be ignored
-        assert_eq!(dirs.len(), 0);
-        assert!(filter.is_none());
-    }
-
-    #[test]
-    fn parse_spec_blank_level_isolated_comma_only() {
-        // The spec should contain zero or more comma-separated string slices,
-        // so a comma-only string should be interpreted as two empty strings
-        // (which should both be treated as invalid, so ignored).
-        let (dirs, filter) = parse_spec(","); // should be ignored
-        assert_eq!(dirs.len(), 0);
-        assert!(filter.is_none());
-    }
-
-    #[test]
-    fn parse_spec_blank_level_isolated_comma_blank() {
-        // The spec should contain zero or more comma-separated string slices,
-        // so this bogus spec should be interpreted as containing one empty
-        // string and one blank string. Both should both be treated as
-        // invalid, so ignored.
-        let (dirs, filter) = parse_spec(",     "); // should be ignored
-        assert_eq!(dirs.len(), 0);
-        assert!(filter.is_none());
-    }
-
-    #[test]
-    fn parse_spec_blank_level_isolated_blank_comma() {
-        // The spec should contain zero or more comma-separated string slices,
-        // so this bogus spec should be interpreted as containing one blank
-        // string and one empty string. Both should both be treated as
-        // invalid, so ignored.
-        let (dirs, filter) = parse_spec("     ,"); // should be ignored
-        assert_eq!(dirs.len(), 0);
-        assert!(filter.is_none());
-    }
-
-    #[test]
-    fn parse_spec_global() {
-        // test parse_spec with no crate
-        let (dirs, filter) = parse_spec("warn,crate2=debug");
-        assert_eq!(dirs.len(), 2);
-        assert_eq!(dirs[0].name, None);
-        assert_eq!(dirs[0].level, LevelFilter::Warn);
-        assert_eq!(dirs[1].name, Some("crate2".to_string()));
-        assert_eq!(dirs[1].level, LevelFilter::Debug);
-        assert!(filter.is_none());
-    }
-
-    #[test]
-    fn parse_spec_global_bare_warn_lc() {
-        // test parse_spec with no crate, in isolation, all lowercase
-        let (dirs, filter) = parse_spec("warn");
-        assert_eq!(dirs.len(), 1);
-        assert_eq!(dirs[0].name, None);
-        assert_eq!(dirs[0].level, LevelFilter::Warn);
-        assert!(filter.is_none());
-    }
-
-    #[test]
-    fn parse_spec_global_bare_warn_uc() {
-        // test parse_spec with no crate, in isolation, all uppercase
-        let (dirs, filter) = parse_spec("WARN");
-        assert_eq!(dirs.len(), 1);
-        assert_eq!(dirs[0].name, None);
-        assert_eq!(dirs[0].level, LevelFilter::Warn);
-        assert!(filter.is_none());
-    }
-
-    #[test]
-    fn parse_spec_global_bare_warn_mixed() {
-        // test parse_spec with no crate, in isolation, mixed case
-        let (dirs, filter) = parse_spec("wArN");
-        assert_eq!(dirs.len(), 1);
-        assert_eq!(dirs[0].name, None);
-        assert_eq!(dirs[0].level, LevelFilter::Warn);
-        assert!(filter.is_none());
-    }
-
-    #[test]
-    fn parse_spec_valid_filter() {
-        let (dirs, filter) = parse_spec("crate1::mod1=error,crate1::mod2,crate2=debug/abc");
-        assert_eq!(dirs.len(), 3);
-        assert_eq!(dirs[0].name, Some("crate1::mod1".to_string()));
-        assert_eq!(dirs[0].level, LevelFilter::Error);
-
-        assert_eq!(dirs[1].name, Some("crate1::mod2".to_string()));
-        assert_eq!(dirs[1].level, LevelFilter::max());
-
-        assert_eq!(dirs[2].name, Some("crate2".to_string()));
-        assert_eq!(dirs[2].level, LevelFilter::Debug);
-        assert!(filter.is_some() && filter.unwrap().to_string() == "abc");
-    }
-
-    #[test]
-    fn parse_spec_invalid_crate_filter() {
-        let (dirs, filter) = parse_spec("crate1::mod1=error=warn,crate2=debug/a.c");
-        assert_eq!(dirs.len(), 1);
-        assert_eq!(dirs[0].name, Some("crate2".to_string()));
-        assert_eq!(dirs[0].level, LevelFilter::Debug);
-        assert!(filter.is_some() && filter.unwrap().to_string() == "a.c");
-    }
-
-    #[test]
-    fn parse_spec_empty_with_filter() {
-        let (dirs, filter) = parse_spec("crate1/a*c");
-        assert_eq!(dirs.len(), 1);
-        assert_eq!(dirs[0].name, Some("crate1".to_string()));
-        assert_eq!(dirs[0].level, LevelFilter::max());
-        assert!(filter.is_some() && filter.unwrap().to_string() == "a*c");
-    }
 }
diff --git a/crates/env_filter/src/parser.rs b/crates/env_filter/src/parser.rs
new file mode 100644
index 00000000..d9158fab
--- /dev/null
+++ b/crates/env_filter/src/parser.rs
@@ -0,0 +1,261 @@
+use log::LevelFilter;
+
+use crate::op;
+use crate::Directive;
+
+/// Parse a logging specification string (e.g: "crate1,crate2::mod3,crate3::x=error/foo")
+/// and return a vector with log directives.
+pub(crate) fn parse_spec(spec: &str) -> (Vec<Directive>, Option<op::FilterOp>) {
+    let mut dirs = Vec::new();
+
+    let mut parts = spec.split('/');
+    let mods = parts.next();
+    let filter = parts.next();
+    if parts.next().is_some() {
+        eprintln!(
+            "warning: invalid logging spec '{}', \
+             ignoring it (too many '/'s)",
+            spec
+        );
+        return (dirs, None);
+    }
+    if let Some(m) = mods {
+        for s in m.split(',').map(|ss| ss.trim()) {
+            if s.is_empty() {
+                continue;
+            }
+            let mut parts = s.split('=');
+            let (log_level, name) =
+                match (parts.next(), parts.next().map(|s| s.trim()), parts.next()) {
+                    (Some(part0), None, None) => {
+                        // if the single argument is a log-level string or number,
+                        // treat that as a global fallback
+                        match part0.parse() {
+                            Ok(num) => (num, None),
+                            Err(_) => (LevelFilter::max(), Some(part0)),
+                        }
+                    }
+                    (Some(part0), Some(""), None) => (LevelFilter::max(), Some(part0)),
+                    (Some(part0), Some(part1), None) => match part1.parse() {
+                        Ok(num) => (num, Some(part0)),
+                        _ => {
+                            eprintln!(
+                                "warning: invalid logging spec '{}', \
+                                 ignoring it",
+                                part1
+                            );
+                            continue;
+                        }
+                    },
+                    _ => {
+                        eprintln!(
+                            "warning: invalid logging spec '{}', \
+                             ignoring it",
+                            s
+                        );
+                        continue;
+                    }
+                };
+            dirs.push(Directive {
+                name: name.map(|s| s.to_string()),
+                level: log_level,
+            });
+        }
+    }
+
+    let filter = filter.and_then(|filter| match op::FilterOp::new(filter) {
+        Ok(re) => Some(re),
+        Err(e) => {
+            eprintln!("warning: invalid regex filter - {}", e);
+            None
+        }
+    });
+
+    (dirs, filter)
+}
+
+#[cfg(test)]
+mod tests {
+    use log::LevelFilter;
+
+    use super::parse_spec;
+
+    #[test]
+    fn parse_spec_valid() {
+        let (dirs, filter) = parse_spec("crate1::mod1=error,crate1::mod2,crate2=debug");
+        assert_eq!(dirs.len(), 3);
+        assert_eq!(dirs[0].name, Some("crate1::mod1".to_string()));
+        assert_eq!(dirs[0].level, LevelFilter::Error);
+
+        assert_eq!(dirs[1].name, Some("crate1::mod2".to_string()));
+        assert_eq!(dirs[1].level, LevelFilter::max());
+
+        assert_eq!(dirs[2].name, Some("crate2".to_string()));
+        assert_eq!(dirs[2].level, LevelFilter::Debug);
+        assert!(filter.is_none());
+    }
+
+    #[test]
+    fn parse_spec_invalid_crate() {
+        // test parse_spec with multiple = in specification
+        let (dirs, filter) = parse_spec("crate1::mod1=warn=info,crate2=debug");
+        assert_eq!(dirs.len(), 1);
+        assert_eq!(dirs[0].name, Some("crate2".to_string()));
+        assert_eq!(dirs[0].level, LevelFilter::Debug);
+        assert!(filter.is_none());
+    }
+
+    #[test]
+    fn parse_spec_invalid_level() {
+        // test parse_spec with 'noNumber' as log level
+        let (dirs, filter) = parse_spec("crate1::mod1=noNumber,crate2=debug");
+        assert_eq!(dirs.len(), 1);
+        assert_eq!(dirs[0].name, Some("crate2".to_string()));
+        assert_eq!(dirs[0].level, LevelFilter::Debug);
+        assert!(filter.is_none());
+    }
+
+    #[test]
+    fn parse_spec_string_level() {
+        // test parse_spec with 'warn' as log level
+        let (dirs, filter) = parse_spec("crate1::mod1=wrong,crate2=warn");
+        assert_eq!(dirs.len(), 1);
+        assert_eq!(dirs[0].name, Some("crate2".to_string()));
+        assert_eq!(dirs[0].level, LevelFilter::Warn);
+        assert!(filter.is_none());
+    }
+
+    #[test]
+    fn parse_spec_empty_level() {
+        // test parse_spec with '' as log level
+        let (dirs, filter) = parse_spec("crate1::mod1=wrong,crate2=");
+        assert_eq!(dirs.len(), 1);
+        assert_eq!(dirs[0].name, Some("crate2".to_string()));
+        assert_eq!(dirs[0].level, LevelFilter::max());
+        assert!(filter.is_none());
+    }
+
+    #[test]
+    fn parse_spec_empty_level_isolated() {
+        // test parse_spec with "" as log level (and the entire spec str)
+        let (dirs, filter) = parse_spec(""); // should be ignored
+        assert_eq!(dirs.len(), 0);
+        assert!(filter.is_none());
+    }
+
+    #[test]
+    fn parse_spec_blank_level_isolated() {
+        // test parse_spec with a white-space-only string specified as the log
+        // level (and the entire spec str)
+        let (dirs, filter) = parse_spec("     "); // should be ignored
+        assert_eq!(dirs.len(), 0);
+        assert!(filter.is_none());
+    }
+
+    #[test]
+    fn parse_spec_blank_level_isolated_comma_only() {
+        // The spec should contain zero or more comma-separated string slices,
+        // so a comma-only string should be interpreted as two empty strings
+        // (which should both be treated as invalid, so ignored).
+        let (dirs, filter) = parse_spec(","); // should be ignored
+        assert_eq!(dirs.len(), 0);
+        assert!(filter.is_none());
+    }
+
+    #[test]
+    fn parse_spec_blank_level_isolated_comma_blank() {
+        // The spec should contain zero or more comma-separated string slices,
+        // so this bogus spec should be interpreted as containing one empty
+        // string and one blank string. Both should both be treated as
+        // invalid, so ignored.
+        let (dirs, filter) = parse_spec(",     "); // should be ignored
+        assert_eq!(dirs.len(), 0);
+        assert!(filter.is_none());
+    }
+
+    #[test]
+    fn parse_spec_blank_level_isolated_blank_comma() {
+        // The spec should contain zero or more comma-separated string slices,
+        // so this bogus spec should be interpreted as containing one blank
+        // string and one empty string. Both should both be treated as
+        // invalid, so ignored.
+        let (dirs, filter) = parse_spec("     ,"); // should be ignored
+        assert_eq!(dirs.len(), 0);
+        assert!(filter.is_none());
+    }
+
+    #[test]
+    fn parse_spec_global() {
+        // test parse_spec with no crate
+        let (dirs, filter) = parse_spec("warn,crate2=debug");
+        assert_eq!(dirs.len(), 2);
+        assert_eq!(dirs[0].name, None);
+        assert_eq!(dirs[0].level, LevelFilter::Warn);
+        assert_eq!(dirs[1].name, Some("crate2".to_string()));
+        assert_eq!(dirs[1].level, LevelFilter::Debug);
+        assert!(filter.is_none());
+    }
+
+    #[test]
+    fn parse_spec_global_bare_warn_lc() {
+        // test parse_spec with no crate, in isolation, all lowercase
+        let (dirs, filter) = parse_spec("warn");
+        assert_eq!(dirs.len(), 1);
+        assert_eq!(dirs[0].name, None);
+        assert_eq!(dirs[0].level, LevelFilter::Warn);
+        assert!(filter.is_none());
+    }
+
+    #[test]
+    fn parse_spec_global_bare_warn_uc() {
+        // test parse_spec with no crate, in isolation, all uppercase
+        let (dirs, filter) = parse_spec("WARN");
+        assert_eq!(dirs.len(), 1);
+        assert_eq!(dirs[0].name, None);
+        assert_eq!(dirs[0].level, LevelFilter::Warn);
+        assert!(filter.is_none());
+    }
+
+    #[test]
+    fn parse_spec_global_bare_warn_mixed() {
+        // test parse_spec with no crate, in isolation, mixed case
+        let (dirs, filter) = parse_spec("wArN");
+        assert_eq!(dirs.len(), 1);
+        assert_eq!(dirs[0].name, None);
+        assert_eq!(dirs[0].level, LevelFilter::Warn);
+        assert!(filter.is_none());
+    }
+
+    #[test]
+    fn parse_spec_valid_filter() {
+        let (dirs, filter) = parse_spec("crate1::mod1=error,crate1::mod2,crate2=debug/abc");
+        assert_eq!(dirs.len(), 3);
+        assert_eq!(dirs[0].name, Some("crate1::mod1".to_string()));
+        assert_eq!(dirs[0].level, LevelFilter::Error);
+
+        assert_eq!(dirs[1].name, Some("crate1::mod2".to_string()));
+        assert_eq!(dirs[1].level, LevelFilter::max());
+
+        assert_eq!(dirs[2].name, Some("crate2".to_string()));
+        assert_eq!(dirs[2].level, LevelFilter::Debug);
+        assert!(filter.is_some() && filter.unwrap().to_string() == "abc");
+    }
+
+    #[test]
+    fn parse_spec_invalid_crate_filter() {
+        let (dirs, filter) = parse_spec("crate1::mod1=error=warn,crate2=debug/a.c");
+        assert_eq!(dirs.len(), 1);
+        assert_eq!(dirs[0].name, Some("crate2".to_string()));
+        assert_eq!(dirs[0].level, LevelFilter::Debug);
+        assert!(filter.is_some() && filter.unwrap().to_string() == "a.c");
+    }
+
+    #[test]
+    fn parse_spec_empty_with_filter() {
+        let (dirs, filter) = parse_spec("crate1/a*c");
+        assert_eq!(dirs.len(), 1);
+        assert_eq!(dirs[0].name, Some("crate1".to_string()));
+        assert_eq!(dirs[0].level, LevelFilter::max());
+        assert!(filter.is_some() && filter.unwrap().to_string() == "a*c");
+    }
+}

From c769e03f40e03e83b972c334195014eddf8b2c9a Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Fri, 19 Jan 2024 11:34:45 -0600
Subject: [PATCH 20/28] refactor(filter): Flatten the mod

---
 crates/env_filter/src/lib.rs    | 16 ++++++++++------
 crates/env_filter/src/parser.rs |  6 +++---
 2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/crates/env_filter/src/lib.rs b/crates/env_filter/src/lib.rs
index a90342e7..3d97d387 100644
--- a/crates/env_filter/src/lib.rs
+++ b/crates/env_filter/src/lib.rs
@@ -50,13 +50,17 @@
 //! }
 //! ```
 
-use log::{Level, LevelFilter, Metadata, Record};
+mod op;
+mod parser;
+
 use std::env;
 use std::fmt;
 use std::mem;
 
-mod op;
-mod parser;
+use log::{Level, LevelFilter, Metadata, Record};
+
+use op::FilterOp;
+use parser::parse_spec;
 
 /// A builder for a log filter.
 ///
@@ -80,7 +84,7 @@ mod parser;
 /// ```
 pub struct Builder {
     directives: Vec<Directive>,
-    filter: Option<op::FilterOp>,
+    filter: Option<FilterOp>,
     built: bool,
 }
 
@@ -146,7 +150,7 @@ impl Builder {
     ///
     /// [Enabling Logging]: ../index.html#enabling-logging
     pub fn parse(&mut self, filters: &str) -> &mut Self {
-        let (directives, filter) = parser::parse_spec(filters);
+        let (directives, filter) = parse_spec(filters);
 
         self.filter = filter;
 
@@ -221,7 +225,7 @@ struct Directive {
 /// [`Builder`]: struct.Builder.html
 pub struct Filter {
     directives: Vec<Directive>,
-    filter: Option<op::FilterOp>,
+    filter: Option<FilterOp>,
 }
 
 impl Filter {
diff --git a/crates/env_filter/src/parser.rs b/crates/env_filter/src/parser.rs
index d9158fab..2d0f90b0 100644
--- a/crates/env_filter/src/parser.rs
+++ b/crates/env_filter/src/parser.rs
@@ -1,11 +1,11 @@
 use log::LevelFilter;
 
-use crate::op;
 use crate::Directive;
+use crate::FilterOp;
 
 /// Parse a logging specification string (e.g: "crate1,crate2::mod3,crate3::x=error/foo")
 /// and return a vector with log directives.
-pub(crate) fn parse_spec(spec: &str) -> (Vec<Directive>, Option<op::FilterOp>) {
+pub(crate) fn parse_spec(spec: &str) -> (Vec<Directive>, Option<FilterOp>) {
     let mut dirs = Vec::new();
 
     let mut parts = spec.split('/');
@@ -63,7 +63,7 @@ pub(crate) fn parse_spec(spec: &str) -> (Vec<Directive>, Option<op::FilterOp>) {
         }
     }
 
-    let filter = filter.and_then(|filter| match op::FilterOp::new(filter) {
+    let filter = filter.and_then(|filter| match FilterOp::new(filter) {
         Ok(re) => Some(re),
         Err(e) => {
             eprintln!("warning: invalid regex filter - {}", e);

From 98c450f85b95779b60be37d847e176856305b6fd Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Fri, 19 Jan 2024 11:36:37 -0600
Subject: [PATCH 21/28] refactor(filter): Pull out directive mod

---
 crates/env_filter/src/directive.rs | 20 ++++++++++++++++++++
 crates/env_filter/src/lib.rs       | 23 ++++-------------------
 2 files changed, 24 insertions(+), 19 deletions(-)
 create mode 100644 crates/env_filter/src/directive.rs

diff --git a/crates/env_filter/src/directive.rs b/crates/env_filter/src/directive.rs
new file mode 100644
index 00000000..3721ef7f
--- /dev/null
+++ b/crates/env_filter/src/directive.rs
@@ -0,0 +1,20 @@
+use log::Level;
+use log::LevelFilter;
+
+#[derive(Debug)]
+pub(crate) struct Directive {
+    pub(crate) name: Option<String>,
+    pub(crate) level: LevelFilter,
+}
+
+// Check whether a level and target are enabled by the set of directives.
+pub(crate) fn enabled(directives: &[Directive], level: Level, target: &str) -> bool {
+    // Search for the longest match, the vector is assumed to be pre-sorted.
+    for directive in directives.iter().rev() {
+        match directive.name {
+            Some(ref name) if !target.starts_with(&**name) => {}
+            Some(..) | None => return level <= directive.level,
+        }
+    }
+    false
+}
diff --git a/crates/env_filter/src/lib.rs b/crates/env_filter/src/lib.rs
index 3d97d387..41b71f8c 100644
--- a/crates/env_filter/src/lib.rs
+++ b/crates/env_filter/src/lib.rs
@@ -50,6 +50,7 @@
 //! }
 //! ```
 
+mod directive;
 mod op;
 mod parser;
 
@@ -57,8 +58,10 @@ use std::env;
 use std::fmt;
 use std::mem;
 
-use log::{Level, LevelFilter, Metadata, Record};
+use log::{LevelFilter, Metadata, Record};
 
+use directive::enabled;
+use directive::Directive;
 use op::FilterOp;
 use parser::parse_spec;
 
@@ -210,12 +213,6 @@ impl fmt::Debug for Builder {
     }
 }
 
-#[derive(Debug)]
-struct Directive {
-    name: Option<String>,
-    level: LevelFilter,
-}
-
 /// A log filter.
 ///
 /// This struct can be used to determine whether or not a log record
@@ -286,18 +283,6 @@ impl fmt::Debug for Filter {
     }
 }
 
-// Check whether a level and target are enabled by the set of directives.
-fn enabled(directives: &[Directive], level: Level, target: &str) -> bool {
-    // Search for the longest match, the vector is assumed to be pre-sorted.
-    for directive in directives.iter().rev() {
-        match directive.name {
-            Some(ref name) if !target.starts_with(&**name) => {}
-            Some(..) | None => return level <= directive.level,
-        }
-    }
-    false
-}
-
 #[cfg(test)]
 mod tests {
     use log::{Level, LevelFilter};

From 841eba41feb44317facc586745b28707590d11fd Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Fri, 19 Jan 2024 11:38:22 -0600
Subject: [PATCH 22/28] refactor(filter): Pull out filter mod

---
 crates/env_filter/src/filter.rs | 546 ++++++++++++++++++++++++++++++++
 crates/env_filter/src/lib.rs    | 544 +------------------------------
 2 files changed, 549 insertions(+), 541 deletions(-)
 create mode 100644 crates/env_filter/src/filter.rs

diff --git a/crates/env_filter/src/filter.rs b/crates/env_filter/src/filter.rs
new file mode 100644
index 00000000..7a052720
--- /dev/null
+++ b/crates/env_filter/src/filter.rs
@@ -0,0 +1,546 @@
+use std::env;
+use std::fmt;
+use std::mem;
+
+use log::{LevelFilter, Metadata, Record};
+
+use crate::enabled;
+use crate::Directive;
+use crate::FilterOp;
+use crate::parse_spec;
+
+/// A builder for a log filter.
+///
+/// It can be used to parse a set of directives from a string before building
+/// a [`Filter`] instance.
+///
+/// ## Example
+///
+/// ```
+/// # use std::env;
+/// use env_filter::Builder;
+///
+/// let mut builder = Builder::new();
+///
+/// // Parse a logging filter from an environment variable.
+/// if let Ok(rust_log) = env::var("RUST_LOG") {
+///     builder.parse(&rust_log);
+/// }
+///
+/// let filter = builder.build();
+/// ```
+pub struct Builder {
+    directives: Vec<Directive>,
+    filter: Option<FilterOp>,
+    built: bool,
+}
+
+impl Builder {
+    /// Initializes the filter builder with defaults.
+    pub fn new() -> Builder {
+        Builder {
+            directives: Vec::new(),
+            filter: None,
+            built: false,
+        }
+    }
+
+    /// Initializes the filter builder from an environment.
+    pub fn from_env(env: &str) -> Builder {
+        let mut builder = Builder::new();
+
+        if let Ok(s) = env::var(env) {
+            builder.parse(&s);
+        }
+
+        builder
+    }
+
+    /// Insert the directive replacing any directive with the same name.
+    fn insert_directive(&mut self, mut directive: Directive) {
+        if let Some(pos) = self
+            .directives
+            .iter()
+            .position(|d| d.name == directive.name)
+        {
+            mem::swap(&mut self.directives[pos], &mut directive);
+        } else {
+            self.directives.push(directive);
+        }
+    }
+
+    /// Adds a directive to the filter for a specific module.
+    pub fn filter_module(&mut self, module: &str, level: LevelFilter) -> &mut Self {
+        self.filter(Some(module), level)
+    }
+
+    /// Adds a directive to the filter for all modules.
+    pub fn filter_level(&mut self, level: LevelFilter) -> &mut Self {
+        self.filter(None, level)
+    }
+
+    /// Adds a directive to the filter.
+    ///
+    /// The given module (if any) will log at most the specified level provided.
+    /// If no module is provided then the filter will apply to all log messages.
+    pub fn filter(&mut self, module: Option<&str>, level: LevelFilter) -> &mut Self {
+        self.insert_directive(Directive {
+            name: module.map(|s| s.to_string()),
+            level,
+        });
+        self
+    }
+
+    /// Parses the directives string.
+    ///
+    /// See the [Enabling Logging] section for more details.
+    ///
+    /// [Enabling Logging]: ../index.html#enabling-logging
+    pub fn parse(&mut self, filters: &str) -> &mut Self {
+        let (directives, filter) = parse_spec(filters);
+
+        self.filter = filter;
+
+        for directive in directives {
+            self.insert_directive(directive);
+        }
+        self
+    }
+
+    /// Build a log filter.
+    pub fn build(&mut self) -> Filter {
+        assert!(!self.built, "attempt to re-use consumed builder");
+        self.built = true;
+
+        let mut directives = Vec::new();
+        if self.directives.is_empty() {
+            // Adds the default filter if none exist
+            directives.push(Directive {
+                name: None,
+                level: LevelFilter::Error,
+            });
+        } else {
+            // Consume directives.
+            directives = mem::take(&mut self.directives);
+            // Sort the directives by length of their name, this allows a
+            // little more efficient lookup at runtime.
+            directives.sort_by(|a, b| {
+                let alen = a.name.as_ref().map(|a| a.len()).unwrap_or(0);
+                let blen = b.name.as_ref().map(|b| b.len()).unwrap_or(0);
+                alen.cmp(&blen)
+            });
+        }
+
+        Filter {
+            directives: mem::take(&mut directives),
+            filter: mem::take(&mut self.filter),
+        }
+    }
+}
+
+impl Default for Builder {
+    fn default() -> Self {
+        Builder::new()
+    }
+}
+
+impl fmt::Debug for Builder {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        if self.built {
+            f.debug_struct("Filter").field("built", &true).finish()
+        } else {
+            f.debug_struct("Filter")
+                .field("filter", &self.filter)
+                .field("directives", &self.directives)
+                .finish()
+        }
+    }
+}
+
+/// A log filter.
+///
+/// This struct can be used to determine whether or not a log record
+/// should be written to the output.
+/// Use the [`Builder`] type to parse and construct a `Filter`.
+///
+/// [`Builder`]: struct.Builder.html
+pub struct Filter {
+    directives: Vec<Directive>,
+    filter: Option<FilterOp>,
+}
+
+impl Filter {
+    /// Returns the maximum `LevelFilter` that this filter instance is
+    /// configured to output.
+    ///
+    /// # Example
+    ///
+    /// ```rust
+    /// use log::LevelFilter;
+    /// use env_filter::Builder;
+    ///
+    /// let mut builder = Builder::new();
+    /// builder.filter(Some("module1"), LevelFilter::Info);
+    /// builder.filter(Some("module2"), LevelFilter::Error);
+    ///
+    /// let filter = builder.build();
+    /// assert_eq!(filter.filter(), LevelFilter::Info);
+    /// ```
+    pub fn filter(&self) -> LevelFilter {
+        self.directives
+            .iter()
+            .map(|d| d.level)
+            .max()
+            .unwrap_or(LevelFilter::Off)
+    }
+
+    /// Checks if this record matches the configured filter.
+    pub fn matches(&self, record: &Record) -> bool {
+        if !self.enabled(record.metadata()) {
+            return false;
+        }
+
+        if let Some(filter) = self.filter.as_ref() {
+            if !filter.is_match(&record.args().to_string()) {
+                return false;
+            }
+        }
+
+        true
+    }
+
+    /// Determines if a log message with the specified metadata would be logged.
+    pub fn enabled(&self, metadata: &Metadata) -> bool {
+        let level = metadata.level();
+        let target = metadata.target();
+
+        enabled(&self.directives, level, target)
+    }
+}
+
+impl fmt::Debug for Filter {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_struct("Filter")
+            .field("filter", &self.filter)
+            .field("directives", &self.directives)
+            .finish()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use log::{Level, LevelFilter};
+
+    use super::{enabled, Builder, Directive, Filter};
+
+    fn make_logger_filter(dirs: Vec<Directive>) -> Filter {
+        let mut logger = Builder::new().build();
+        logger.directives = dirs;
+        logger
+    }
+
+    #[test]
+    fn filter_info() {
+        let logger = Builder::new().filter(None, LevelFilter::Info).build();
+        assert!(enabled(&logger.directives, Level::Info, "crate1"));
+        assert!(!enabled(&logger.directives, Level::Debug, "crate1"));
+    }
+
+    #[test]
+    fn filter_beginning_longest_match() {
+        let logger = Builder::new()
+            .filter(Some("crate2"), LevelFilter::Info)
+            .filter(Some("crate2::mod"), LevelFilter::Debug)
+            .filter(Some("crate1::mod1"), LevelFilter::Warn)
+            .build();
+        assert!(enabled(&logger.directives, Level::Debug, "crate2::mod1"));
+        assert!(!enabled(&logger.directives, Level::Debug, "crate2"));
+    }
+
+    // Some of our tests are only correct or complete when they cover the full
+    // universe of variants for log::Level. In the unlikely event that a new
+    // variant is added in the future, this test will detect the scenario and
+    // alert us to the need to review and update the tests. In such a
+    // situation, this test will fail to compile, and the error message will
+    // look something like this:
+    //
+    //     error[E0004]: non-exhaustive patterns: `NewVariant` not covered
+    //        --> src/filter/mod.rs:413:15
+    //         |
+    //     413 |         match level_universe {
+    //         |               ^^^^^^^^^^^^^^ pattern `NewVariant` not covered
+    #[test]
+    fn ensure_tests_cover_level_universe() {
+        let level_universe: Level = Level::Trace; // use of trace variant is arbitrary
+        match level_universe {
+            Level::Error | Level::Warn | Level::Info | Level::Debug | Level::Trace => (),
+        }
+    }
+
+    #[test]
+    fn parse_default() {
+        let logger = Builder::new().parse("info,crate1::mod1=warn").build();
+        assert!(enabled(&logger.directives, Level::Warn, "crate1::mod1"));
+        assert!(enabled(&logger.directives, Level::Info, "crate2::mod2"));
+    }
+
+    #[test]
+    fn parse_default_bare_level_off_lc() {
+        let logger = Builder::new().parse("off").build();
+        assert!(!enabled(&logger.directives, Level::Error, ""));
+        assert!(!enabled(&logger.directives, Level::Warn, ""));
+        assert!(!enabled(&logger.directives, Level::Info, ""));
+        assert!(!enabled(&logger.directives, Level::Debug, ""));
+        assert!(!enabled(&logger.directives, Level::Trace, ""));
+    }
+
+    #[test]
+    fn parse_default_bare_level_off_uc() {
+        let logger = Builder::new().parse("OFF").build();
+        assert!(!enabled(&logger.directives, Level::Error, ""));
+        assert!(!enabled(&logger.directives, Level::Warn, ""));
+        assert!(!enabled(&logger.directives, Level::Info, ""));
+        assert!(!enabled(&logger.directives, Level::Debug, ""));
+        assert!(!enabled(&logger.directives, Level::Trace, ""));
+    }
+
+    #[test]
+    fn parse_default_bare_level_error_lc() {
+        let logger = Builder::new().parse("error").build();
+        assert!(enabled(&logger.directives, Level::Error, ""));
+        assert!(!enabled(&logger.directives, Level::Warn, ""));
+        assert!(!enabled(&logger.directives, Level::Info, ""));
+        assert!(!enabled(&logger.directives, Level::Debug, ""));
+        assert!(!enabled(&logger.directives, Level::Trace, ""));
+    }
+
+    #[test]
+    fn parse_default_bare_level_error_uc() {
+        let logger = Builder::new().parse("ERROR").build();
+        assert!(enabled(&logger.directives, Level::Error, ""));
+        assert!(!enabled(&logger.directives, Level::Warn, ""));
+        assert!(!enabled(&logger.directives, Level::Info, ""));
+        assert!(!enabled(&logger.directives, Level::Debug, ""));
+        assert!(!enabled(&logger.directives, Level::Trace, ""));
+    }
+
+    #[test]
+    fn parse_default_bare_level_warn_lc() {
+        let logger = Builder::new().parse("warn").build();
+        assert!(enabled(&logger.directives, Level::Error, ""));
+        assert!(enabled(&logger.directives, Level::Warn, ""));
+        assert!(!enabled(&logger.directives, Level::Info, ""));
+        assert!(!enabled(&logger.directives, Level::Debug, ""));
+        assert!(!enabled(&logger.directives, Level::Trace, ""));
+    }
+
+    #[test]
+    fn parse_default_bare_level_warn_uc() {
+        let logger = Builder::new().parse("WARN").build();
+        assert!(enabled(&logger.directives, Level::Error, ""));
+        assert!(enabled(&logger.directives, Level::Warn, ""));
+        assert!(!enabled(&logger.directives, Level::Info, ""));
+        assert!(!enabled(&logger.directives, Level::Debug, ""));
+        assert!(!enabled(&logger.directives, Level::Trace, ""));
+    }
+
+    #[test]
+    fn parse_default_bare_level_info_lc() {
+        let logger = Builder::new().parse("info").build();
+        assert!(enabled(&logger.directives, Level::Error, ""));
+        assert!(enabled(&logger.directives, Level::Warn, ""));
+        assert!(enabled(&logger.directives, Level::Info, ""));
+        assert!(!enabled(&logger.directives, Level::Debug, ""));
+        assert!(!enabled(&logger.directives, Level::Trace, ""));
+    }
+
+    #[test]
+    fn parse_default_bare_level_info_uc() {
+        let logger = Builder::new().parse("INFO").build();
+        assert!(enabled(&logger.directives, Level::Error, ""));
+        assert!(enabled(&logger.directives, Level::Warn, ""));
+        assert!(enabled(&logger.directives, Level::Info, ""));
+        assert!(!enabled(&logger.directives, Level::Debug, ""));
+        assert!(!enabled(&logger.directives, Level::Trace, ""));
+    }
+
+    #[test]
+    fn parse_default_bare_level_debug_lc() {
+        let logger = Builder::new().parse("debug").build();
+        assert!(enabled(&logger.directives, Level::Error, ""));
+        assert!(enabled(&logger.directives, Level::Warn, ""));
+        assert!(enabled(&logger.directives, Level::Info, ""));
+        assert!(enabled(&logger.directives, Level::Debug, ""));
+        assert!(!enabled(&logger.directives, Level::Trace, ""));
+    }
+
+    #[test]
+    fn parse_default_bare_level_debug_uc() {
+        let logger = Builder::new().parse("DEBUG").build();
+        assert!(enabled(&logger.directives, Level::Error, ""));
+        assert!(enabled(&logger.directives, Level::Warn, ""));
+        assert!(enabled(&logger.directives, Level::Info, ""));
+        assert!(enabled(&logger.directives, Level::Debug, ""));
+        assert!(!enabled(&logger.directives, Level::Trace, ""));
+    }
+
+    #[test]
+    fn parse_default_bare_level_trace_lc() {
+        let logger = Builder::new().parse("trace").build();
+        assert!(enabled(&logger.directives, Level::Error, ""));
+        assert!(enabled(&logger.directives, Level::Warn, ""));
+        assert!(enabled(&logger.directives, Level::Info, ""));
+        assert!(enabled(&logger.directives, Level::Debug, ""));
+        assert!(enabled(&logger.directives, Level::Trace, ""));
+    }
+
+    #[test]
+    fn parse_default_bare_level_trace_uc() {
+        let logger = Builder::new().parse("TRACE").build();
+        assert!(enabled(&logger.directives, Level::Error, ""));
+        assert!(enabled(&logger.directives, Level::Warn, ""));
+        assert!(enabled(&logger.directives, Level::Info, ""));
+        assert!(enabled(&logger.directives, Level::Debug, ""));
+        assert!(enabled(&logger.directives, Level::Trace, ""));
+    }
+
+    // In practice, the desired log level is typically specified by a token
+    // that is either all lowercase (e.g., 'trace') or all uppercase (.e.g,
+    // 'TRACE'), but this tests serves as a reminder that
+    // log::Level::from_str() ignores all case variants.
+    #[test]
+    fn parse_default_bare_level_debug_mixed() {
+        {
+            let logger = Builder::new().parse("Debug").build();
+            assert!(enabled(&logger.directives, Level::Error, ""));
+            assert!(enabled(&logger.directives, Level::Warn, ""));
+            assert!(enabled(&logger.directives, Level::Info, ""));
+            assert!(enabled(&logger.directives, Level::Debug, ""));
+            assert!(!enabled(&logger.directives, Level::Trace, ""));
+        }
+        {
+            let logger = Builder::new().parse("debuG").build();
+            assert!(enabled(&logger.directives, Level::Error, ""));
+            assert!(enabled(&logger.directives, Level::Warn, ""));
+            assert!(enabled(&logger.directives, Level::Info, ""));
+            assert!(enabled(&logger.directives, Level::Debug, ""));
+            assert!(!enabled(&logger.directives, Level::Trace, ""));
+        }
+        {
+            let logger = Builder::new().parse("deBug").build();
+            assert!(enabled(&logger.directives, Level::Error, ""));
+            assert!(enabled(&logger.directives, Level::Warn, ""));
+            assert!(enabled(&logger.directives, Level::Info, ""));
+            assert!(enabled(&logger.directives, Level::Debug, ""));
+            assert!(!enabled(&logger.directives, Level::Trace, ""));
+        }
+        {
+            let logger = Builder::new().parse("DeBuG").build(); // LaTeX flavor!
+            assert!(enabled(&logger.directives, Level::Error, ""));
+            assert!(enabled(&logger.directives, Level::Warn, ""));
+            assert!(enabled(&logger.directives, Level::Info, ""));
+            assert!(enabled(&logger.directives, Level::Debug, ""));
+            assert!(!enabled(&logger.directives, Level::Trace, ""));
+        }
+    }
+
+    #[test]
+    fn match_full_path() {
+        let logger = make_logger_filter(vec![
+            Directive {
+                name: Some("crate2".to_string()),
+                level: LevelFilter::Info,
+            },
+            Directive {
+                name: Some("crate1::mod1".to_string()),
+                level: LevelFilter::Warn,
+            },
+        ]);
+        assert!(enabled(&logger.directives, Level::Warn, "crate1::mod1"));
+        assert!(!enabled(&logger.directives, Level::Info, "crate1::mod1"));
+        assert!(enabled(&logger.directives, Level::Info, "crate2"));
+        assert!(!enabled(&logger.directives, Level::Debug, "crate2"));
+    }
+
+    #[test]
+    fn no_match() {
+        let logger = make_logger_filter(vec![
+            Directive {
+                name: Some("crate2".to_string()),
+                level: LevelFilter::Info,
+            },
+            Directive {
+                name: Some("crate1::mod1".to_string()),
+                level: LevelFilter::Warn,
+            },
+        ]);
+        assert!(!enabled(&logger.directives, Level::Warn, "crate3"));
+    }
+
+    #[test]
+    fn match_beginning() {
+        let logger = make_logger_filter(vec![
+            Directive {
+                name: Some("crate2".to_string()),
+                level: LevelFilter::Info,
+            },
+            Directive {
+                name: Some("crate1::mod1".to_string()),
+                level: LevelFilter::Warn,
+            },
+        ]);
+        assert!(enabled(&logger.directives, Level::Info, "crate2::mod1"));
+    }
+
+    #[test]
+    fn match_beginning_longest_match() {
+        let logger = make_logger_filter(vec![
+            Directive {
+                name: Some("crate2".to_string()),
+                level: LevelFilter::Info,
+            },
+            Directive {
+                name: Some("crate2::mod".to_string()),
+                level: LevelFilter::Debug,
+            },
+            Directive {
+                name: Some("crate1::mod1".to_string()),
+                level: LevelFilter::Warn,
+            },
+        ]);
+        assert!(enabled(&logger.directives, Level::Debug, "crate2::mod1"));
+        assert!(!enabled(&logger.directives, Level::Debug, "crate2"));
+    }
+
+    #[test]
+    fn match_default() {
+        let logger = make_logger_filter(vec![
+            Directive {
+                name: None,
+                level: LevelFilter::Info,
+            },
+            Directive {
+                name: Some("crate1::mod1".to_string()),
+                level: LevelFilter::Warn,
+            },
+        ]);
+        assert!(enabled(&logger.directives, Level::Warn, "crate1::mod1"));
+        assert!(enabled(&logger.directives, Level::Info, "crate2::mod2"));
+    }
+
+    #[test]
+    fn zero_level() {
+        let logger = make_logger_filter(vec![
+            Directive {
+                name: None,
+                level: LevelFilter::Info,
+            },
+            Directive {
+                name: Some("crate1::mod1".to_string()),
+                level: LevelFilter::Off,
+            },
+        ]);
+        assert!(!enabled(&logger.directives, Level::Error, "crate1::mod1"));
+        assert!(enabled(&logger.directives, Level::Info, "crate2::mod2"));
+    }
+}
diff --git a/crates/env_filter/src/lib.rs b/crates/env_filter/src/lib.rs
index 41b71f8c..494b82da 100644
--- a/crates/env_filter/src/lib.rs
+++ b/crates/env_filter/src/lib.rs
@@ -51,552 +51,14 @@
 //! ```
 
 mod directive;
+mod filter;
 mod op;
 mod parser;
 
-use std::env;
-use std::fmt;
-use std::mem;
-
-use log::{LevelFilter, Metadata, Record};
-
 use directive::enabled;
 use directive::Directive;
 use op::FilterOp;
 use parser::parse_spec;
 
-/// A builder for a log filter.
-///
-/// It can be used to parse a set of directives from a string before building
-/// a [`Filter`] instance.
-///
-/// ## Example
-///
-/// ```
-/// # use std::env;
-/// use env_filter::Builder;
-///
-/// let mut builder = Builder::new();
-///
-/// // Parse a logging filter from an environment variable.
-/// if let Ok(rust_log) = env::var("RUST_LOG") {
-///     builder.parse(&rust_log);
-/// }
-///
-/// let filter = builder.build();
-/// ```
-pub struct Builder {
-    directives: Vec<Directive>,
-    filter: Option<FilterOp>,
-    built: bool,
-}
-
-impl Builder {
-    /// Initializes the filter builder with defaults.
-    pub fn new() -> Builder {
-        Builder {
-            directives: Vec::new(),
-            filter: None,
-            built: false,
-        }
-    }
-
-    /// Initializes the filter builder from an environment.
-    pub fn from_env(env: &str) -> Builder {
-        let mut builder = Builder::new();
-
-        if let Ok(s) = env::var(env) {
-            builder.parse(&s);
-        }
-
-        builder
-    }
-
-    /// Insert the directive replacing any directive with the same name.
-    fn insert_directive(&mut self, mut directive: Directive) {
-        if let Some(pos) = self
-            .directives
-            .iter()
-            .position(|d| d.name == directive.name)
-        {
-            mem::swap(&mut self.directives[pos], &mut directive);
-        } else {
-            self.directives.push(directive);
-        }
-    }
-
-    /// Adds a directive to the filter for a specific module.
-    pub fn filter_module(&mut self, module: &str, level: LevelFilter) -> &mut Self {
-        self.filter(Some(module), level)
-    }
-
-    /// Adds a directive to the filter for all modules.
-    pub fn filter_level(&mut self, level: LevelFilter) -> &mut Self {
-        self.filter(None, level)
-    }
-
-    /// Adds a directive to the filter.
-    ///
-    /// The given module (if any) will log at most the specified level provided.
-    /// If no module is provided then the filter will apply to all log messages.
-    pub fn filter(&mut self, module: Option<&str>, level: LevelFilter) -> &mut Self {
-        self.insert_directive(Directive {
-            name: module.map(|s| s.to_string()),
-            level,
-        });
-        self
-    }
-
-    /// Parses the directives string.
-    ///
-    /// See the [Enabling Logging] section for more details.
-    ///
-    /// [Enabling Logging]: ../index.html#enabling-logging
-    pub fn parse(&mut self, filters: &str) -> &mut Self {
-        let (directives, filter) = parse_spec(filters);
-
-        self.filter = filter;
-
-        for directive in directives {
-            self.insert_directive(directive);
-        }
-        self
-    }
-
-    /// Build a log filter.
-    pub fn build(&mut self) -> Filter {
-        assert!(!self.built, "attempt to re-use consumed builder");
-        self.built = true;
-
-        let mut directives = Vec::new();
-        if self.directives.is_empty() {
-            // Adds the default filter if none exist
-            directives.push(Directive {
-                name: None,
-                level: LevelFilter::Error,
-            });
-        } else {
-            // Consume directives.
-            directives = mem::take(&mut self.directives);
-            // Sort the directives by length of their name, this allows a
-            // little more efficient lookup at runtime.
-            directives.sort_by(|a, b| {
-                let alen = a.name.as_ref().map(|a| a.len()).unwrap_or(0);
-                let blen = b.name.as_ref().map(|b| b.len()).unwrap_or(0);
-                alen.cmp(&blen)
-            });
-        }
-
-        Filter {
-            directives: mem::take(&mut directives),
-            filter: mem::take(&mut self.filter),
-        }
-    }
-}
-
-impl Default for Builder {
-    fn default() -> Self {
-        Builder::new()
-    }
-}
-
-impl fmt::Debug for Builder {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        if self.built {
-            f.debug_struct("Filter").field("built", &true).finish()
-        } else {
-            f.debug_struct("Filter")
-                .field("filter", &self.filter)
-                .field("directives", &self.directives)
-                .finish()
-        }
-    }
-}
-
-/// A log filter.
-///
-/// This struct can be used to determine whether or not a log record
-/// should be written to the output.
-/// Use the [`Builder`] type to parse and construct a `Filter`.
-///
-/// [`Builder`]: struct.Builder.html
-pub struct Filter {
-    directives: Vec<Directive>,
-    filter: Option<FilterOp>,
-}
-
-impl Filter {
-    /// Returns the maximum `LevelFilter` that this filter instance is
-    /// configured to output.
-    ///
-    /// # Example
-    ///
-    /// ```rust
-    /// use log::LevelFilter;
-    /// use env_filter::Builder;
-    ///
-    /// let mut builder = Builder::new();
-    /// builder.filter(Some("module1"), LevelFilter::Info);
-    /// builder.filter(Some("module2"), LevelFilter::Error);
-    ///
-    /// let filter = builder.build();
-    /// assert_eq!(filter.filter(), LevelFilter::Info);
-    /// ```
-    pub fn filter(&self) -> LevelFilter {
-        self.directives
-            .iter()
-            .map(|d| d.level)
-            .max()
-            .unwrap_or(LevelFilter::Off)
-    }
-
-    /// Checks if this record matches the configured filter.
-    pub fn matches(&self, record: &Record) -> bool {
-        if !self.enabled(record.metadata()) {
-            return false;
-        }
-
-        if let Some(filter) = self.filter.as_ref() {
-            if !filter.is_match(&record.args().to_string()) {
-                return false;
-            }
-        }
-
-        true
-    }
-
-    /// Determines if a log message with the specified metadata would be logged.
-    pub fn enabled(&self, metadata: &Metadata) -> bool {
-        let level = metadata.level();
-        let target = metadata.target();
-
-        enabled(&self.directives, level, target)
-    }
-}
-
-impl fmt::Debug for Filter {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        f.debug_struct("Filter")
-            .field("filter", &self.filter)
-            .field("directives", &self.directives)
-            .finish()
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use log::{Level, LevelFilter};
-
-    use super::{enabled, Builder, Directive, Filter};
-
-    fn make_logger_filter(dirs: Vec<Directive>) -> Filter {
-        let mut logger = Builder::new().build();
-        logger.directives = dirs;
-        logger
-    }
-
-    #[test]
-    fn filter_info() {
-        let logger = Builder::new().filter(None, LevelFilter::Info).build();
-        assert!(enabled(&logger.directives, Level::Info, "crate1"));
-        assert!(!enabled(&logger.directives, Level::Debug, "crate1"));
-    }
-
-    #[test]
-    fn filter_beginning_longest_match() {
-        let logger = Builder::new()
-            .filter(Some("crate2"), LevelFilter::Info)
-            .filter(Some("crate2::mod"), LevelFilter::Debug)
-            .filter(Some("crate1::mod1"), LevelFilter::Warn)
-            .build();
-        assert!(enabled(&logger.directives, Level::Debug, "crate2::mod1"));
-        assert!(!enabled(&logger.directives, Level::Debug, "crate2"));
-    }
-
-    // Some of our tests are only correct or complete when they cover the full
-    // universe of variants for log::Level. In the unlikely event that a new
-    // variant is added in the future, this test will detect the scenario and
-    // alert us to the need to review and update the tests. In such a
-    // situation, this test will fail to compile, and the error message will
-    // look something like this:
-    //
-    //     error[E0004]: non-exhaustive patterns: `NewVariant` not covered
-    //        --> src/filter/mod.rs:413:15
-    //         |
-    //     413 |         match level_universe {
-    //         |               ^^^^^^^^^^^^^^ pattern `NewVariant` not covered
-    #[test]
-    fn ensure_tests_cover_level_universe() {
-        let level_universe: Level = Level::Trace; // use of trace variant is arbitrary
-        match level_universe {
-            Level::Error | Level::Warn | Level::Info | Level::Debug | Level::Trace => (),
-        }
-    }
-
-    #[test]
-    fn parse_default() {
-        let logger = Builder::new().parse("info,crate1::mod1=warn").build();
-        assert!(enabled(&logger.directives, Level::Warn, "crate1::mod1"));
-        assert!(enabled(&logger.directives, Level::Info, "crate2::mod2"));
-    }
-
-    #[test]
-    fn parse_default_bare_level_off_lc() {
-        let logger = Builder::new().parse("off").build();
-        assert!(!enabled(&logger.directives, Level::Error, ""));
-        assert!(!enabled(&logger.directives, Level::Warn, ""));
-        assert!(!enabled(&logger.directives, Level::Info, ""));
-        assert!(!enabled(&logger.directives, Level::Debug, ""));
-        assert!(!enabled(&logger.directives, Level::Trace, ""));
-    }
-
-    #[test]
-    fn parse_default_bare_level_off_uc() {
-        let logger = Builder::new().parse("OFF").build();
-        assert!(!enabled(&logger.directives, Level::Error, ""));
-        assert!(!enabled(&logger.directives, Level::Warn, ""));
-        assert!(!enabled(&logger.directives, Level::Info, ""));
-        assert!(!enabled(&logger.directives, Level::Debug, ""));
-        assert!(!enabled(&logger.directives, Level::Trace, ""));
-    }
-
-    #[test]
-    fn parse_default_bare_level_error_lc() {
-        let logger = Builder::new().parse("error").build();
-        assert!(enabled(&logger.directives, Level::Error, ""));
-        assert!(!enabled(&logger.directives, Level::Warn, ""));
-        assert!(!enabled(&logger.directives, Level::Info, ""));
-        assert!(!enabled(&logger.directives, Level::Debug, ""));
-        assert!(!enabled(&logger.directives, Level::Trace, ""));
-    }
-
-    #[test]
-    fn parse_default_bare_level_error_uc() {
-        let logger = Builder::new().parse("ERROR").build();
-        assert!(enabled(&logger.directives, Level::Error, ""));
-        assert!(!enabled(&logger.directives, Level::Warn, ""));
-        assert!(!enabled(&logger.directives, Level::Info, ""));
-        assert!(!enabled(&logger.directives, Level::Debug, ""));
-        assert!(!enabled(&logger.directives, Level::Trace, ""));
-    }
-
-    #[test]
-    fn parse_default_bare_level_warn_lc() {
-        let logger = Builder::new().parse("warn").build();
-        assert!(enabled(&logger.directives, Level::Error, ""));
-        assert!(enabled(&logger.directives, Level::Warn, ""));
-        assert!(!enabled(&logger.directives, Level::Info, ""));
-        assert!(!enabled(&logger.directives, Level::Debug, ""));
-        assert!(!enabled(&logger.directives, Level::Trace, ""));
-    }
-
-    #[test]
-    fn parse_default_bare_level_warn_uc() {
-        let logger = Builder::new().parse("WARN").build();
-        assert!(enabled(&logger.directives, Level::Error, ""));
-        assert!(enabled(&logger.directives, Level::Warn, ""));
-        assert!(!enabled(&logger.directives, Level::Info, ""));
-        assert!(!enabled(&logger.directives, Level::Debug, ""));
-        assert!(!enabled(&logger.directives, Level::Trace, ""));
-    }
-
-    #[test]
-    fn parse_default_bare_level_info_lc() {
-        let logger = Builder::new().parse("info").build();
-        assert!(enabled(&logger.directives, Level::Error, ""));
-        assert!(enabled(&logger.directives, Level::Warn, ""));
-        assert!(enabled(&logger.directives, Level::Info, ""));
-        assert!(!enabled(&logger.directives, Level::Debug, ""));
-        assert!(!enabled(&logger.directives, Level::Trace, ""));
-    }
-
-    #[test]
-    fn parse_default_bare_level_info_uc() {
-        let logger = Builder::new().parse("INFO").build();
-        assert!(enabled(&logger.directives, Level::Error, ""));
-        assert!(enabled(&logger.directives, Level::Warn, ""));
-        assert!(enabled(&logger.directives, Level::Info, ""));
-        assert!(!enabled(&logger.directives, Level::Debug, ""));
-        assert!(!enabled(&logger.directives, Level::Trace, ""));
-    }
-
-    #[test]
-    fn parse_default_bare_level_debug_lc() {
-        let logger = Builder::new().parse("debug").build();
-        assert!(enabled(&logger.directives, Level::Error, ""));
-        assert!(enabled(&logger.directives, Level::Warn, ""));
-        assert!(enabled(&logger.directives, Level::Info, ""));
-        assert!(enabled(&logger.directives, Level::Debug, ""));
-        assert!(!enabled(&logger.directives, Level::Trace, ""));
-    }
-
-    #[test]
-    fn parse_default_bare_level_debug_uc() {
-        let logger = Builder::new().parse("DEBUG").build();
-        assert!(enabled(&logger.directives, Level::Error, ""));
-        assert!(enabled(&logger.directives, Level::Warn, ""));
-        assert!(enabled(&logger.directives, Level::Info, ""));
-        assert!(enabled(&logger.directives, Level::Debug, ""));
-        assert!(!enabled(&logger.directives, Level::Trace, ""));
-    }
-
-    #[test]
-    fn parse_default_bare_level_trace_lc() {
-        let logger = Builder::new().parse("trace").build();
-        assert!(enabled(&logger.directives, Level::Error, ""));
-        assert!(enabled(&logger.directives, Level::Warn, ""));
-        assert!(enabled(&logger.directives, Level::Info, ""));
-        assert!(enabled(&logger.directives, Level::Debug, ""));
-        assert!(enabled(&logger.directives, Level::Trace, ""));
-    }
-
-    #[test]
-    fn parse_default_bare_level_trace_uc() {
-        let logger = Builder::new().parse("TRACE").build();
-        assert!(enabled(&logger.directives, Level::Error, ""));
-        assert!(enabled(&logger.directives, Level::Warn, ""));
-        assert!(enabled(&logger.directives, Level::Info, ""));
-        assert!(enabled(&logger.directives, Level::Debug, ""));
-        assert!(enabled(&logger.directives, Level::Trace, ""));
-    }
-
-    // In practice, the desired log level is typically specified by a token
-    // that is either all lowercase (e.g., 'trace') or all uppercase (.e.g,
-    // 'TRACE'), but this tests serves as a reminder that
-    // log::Level::from_str() ignores all case variants.
-    #[test]
-    fn parse_default_bare_level_debug_mixed() {
-        {
-            let logger = Builder::new().parse("Debug").build();
-            assert!(enabled(&logger.directives, Level::Error, ""));
-            assert!(enabled(&logger.directives, Level::Warn, ""));
-            assert!(enabled(&logger.directives, Level::Info, ""));
-            assert!(enabled(&logger.directives, Level::Debug, ""));
-            assert!(!enabled(&logger.directives, Level::Trace, ""));
-        }
-        {
-            let logger = Builder::new().parse("debuG").build();
-            assert!(enabled(&logger.directives, Level::Error, ""));
-            assert!(enabled(&logger.directives, Level::Warn, ""));
-            assert!(enabled(&logger.directives, Level::Info, ""));
-            assert!(enabled(&logger.directives, Level::Debug, ""));
-            assert!(!enabled(&logger.directives, Level::Trace, ""));
-        }
-        {
-            let logger = Builder::new().parse("deBug").build();
-            assert!(enabled(&logger.directives, Level::Error, ""));
-            assert!(enabled(&logger.directives, Level::Warn, ""));
-            assert!(enabled(&logger.directives, Level::Info, ""));
-            assert!(enabled(&logger.directives, Level::Debug, ""));
-            assert!(!enabled(&logger.directives, Level::Trace, ""));
-        }
-        {
-            let logger = Builder::new().parse("DeBuG").build(); // LaTeX flavor!
-            assert!(enabled(&logger.directives, Level::Error, ""));
-            assert!(enabled(&logger.directives, Level::Warn, ""));
-            assert!(enabled(&logger.directives, Level::Info, ""));
-            assert!(enabled(&logger.directives, Level::Debug, ""));
-            assert!(!enabled(&logger.directives, Level::Trace, ""));
-        }
-    }
-
-    #[test]
-    fn match_full_path() {
-        let logger = make_logger_filter(vec![
-            Directive {
-                name: Some("crate2".to_string()),
-                level: LevelFilter::Info,
-            },
-            Directive {
-                name: Some("crate1::mod1".to_string()),
-                level: LevelFilter::Warn,
-            },
-        ]);
-        assert!(enabled(&logger.directives, Level::Warn, "crate1::mod1"));
-        assert!(!enabled(&logger.directives, Level::Info, "crate1::mod1"));
-        assert!(enabled(&logger.directives, Level::Info, "crate2"));
-        assert!(!enabled(&logger.directives, Level::Debug, "crate2"));
-    }
-
-    #[test]
-    fn no_match() {
-        let logger = make_logger_filter(vec![
-            Directive {
-                name: Some("crate2".to_string()),
-                level: LevelFilter::Info,
-            },
-            Directive {
-                name: Some("crate1::mod1".to_string()),
-                level: LevelFilter::Warn,
-            },
-        ]);
-        assert!(!enabled(&logger.directives, Level::Warn, "crate3"));
-    }
-
-    #[test]
-    fn match_beginning() {
-        let logger = make_logger_filter(vec![
-            Directive {
-                name: Some("crate2".to_string()),
-                level: LevelFilter::Info,
-            },
-            Directive {
-                name: Some("crate1::mod1".to_string()),
-                level: LevelFilter::Warn,
-            },
-        ]);
-        assert!(enabled(&logger.directives, Level::Info, "crate2::mod1"));
-    }
-
-    #[test]
-    fn match_beginning_longest_match() {
-        let logger = make_logger_filter(vec![
-            Directive {
-                name: Some("crate2".to_string()),
-                level: LevelFilter::Info,
-            },
-            Directive {
-                name: Some("crate2::mod".to_string()),
-                level: LevelFilter::Debug,
-            },
-            Directive {
-                name: Some("crate1::mod1".to_string()),
-                level: LevelFilter::Warn,
-            },
-        ]);
-        assert!(enabled(&logger.directives, Level::Debug, "crate2::mod1"));
-        assert!(!enabled(&logger.directives, Level::Debug, "crate2"));
-    }
-
-    #[test]
-    fn match_default() {
-        let logger = make_logger_filter(vec![
-            Directive {
-                name: None,
-                level: LevelFilter::Info,
-            },
-            Directive {
-                name: Some("crate1::mod1".to_string()),
-                level: LevelFilter::Warn,
-            },
-        ]);
-        assert!(enabled(&logger.directives, Level::Warn, "crate1::mod1"));
-        assert!(enabled(&logger.directives, Level::Info, "crate2::mod2"));
-    }
-
-    #[test]
-    fn zero_level() {
-        let logger = make_logger_filter(vec![
-            Directive {
-                name: None,
-                level: LevelFilter::Info,
-            },
-            Directive {
-                name: Some("crate1::mod1".to_string()),
-                level: LevelFilter::Off,
-            },
-        ]);
-        assert!(!enabled(&logger.directives, Level::Error, "crate1::mod1"));
-        assert!(enabled(&logger.directives, Level::Info, "crate2::mod2"));
-    }
-}
+pub use filter::Builder;
+pub use filter::Filter;

From e6e2b633688a56a53ad718b3b498243cb3893d52 Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Fri, 19 Jan 2024 11:44:39 -0600
Subject: [PATCH 23/28] fix(log)!: Dont re-export env_filter

This lets us shrink our public API
---
 examples/custom_logger.rs | 59 ---------------------------------------
 src/lib.rs                |  2 --
 src/logger.rs             |  6 ++--
 3 files changed, 2 insertions(+), 65 deletions(-)
 delete mode 100644 examples/custom_logger.rs

diff --git a/examples/custom_logger.rs b/examples/custom_logger.rs
deleted file mode 100644
index e924faee..00000000
--- a/examples/custom_logger.rs
+++ /dev/null
@@ -1,59 +0,0 @@
-/*!
-Using `env_logger` to drive a custom logger.
-
-Before running this example, try setting the `MY_LOG_LEVEL` environment variable to `info`:
-
-```no_run,shell
-$ export MY_LOG_LEVEL='info'
-```
-
-If you only want to change the way logs are formatted, look at the `custom_format` example.
-*/
-
-use env_logger::filter::{Builder, Filter};
-
-use log::{info, Log, Metadata, Record, SetLoggerError};
-
-const FILTER_ENV: &str = "MY_LOG_LEVEL";
-
-struct MyLogger {
-    inner: Filter,
-}
-
-impl MyLogger {
-    fn new() -> MyLogger {
-        let mut builder = Builder::from_env(FILTER_ENV);
-
-        MyLogger {
-            inner: builder.build(),
-        }
-    }
-
-    fn init() -> Result<(), SetLoggerError> {
-        let logger = Self::new();
-
-        log::set_max_level(logger.inner.filter());
-        log::set_boxed_logger(Box::new(logger))
-    }
-}
-
-impl Log for MyLogger {
-    fn enabled(&self, metadata: &Metadata) -> bool {
-        self.inner.enabled(metadata)
-    }
-
-    fn log(&self, record: &Record) {
-        // Check if the record is matched by the logger before logging
-        if self.inner.matches(record) {
-            println!("{} - {}", record.level(), record.args());
-        }
-    }
-
-    fn flush(&self) {}
-}
-
-fn main() {
-    MyLogger::init().unwrap();
-
-    info!("a log from `MyLogger`");
-}
diff --git a/src/lib.rs b/src/lib.rs
index 76cbf3a5..26f25b85 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -277,8 +277,6 @@
 
 mod logger;
 
-#[doc(inline)]
-pub use ::env_filter as filter;
 pub mod fmt;
 
 pub use self::fmt::{Target, TimestampPrecision, WriteStyle};
diff --git a/src/logger.rs b/src/logger.rs
index 1e7d5894..18bfe9fa 100644
--- a/src/logger.rs
+++ b/src/logger.rs
@@ -2,8 +2,6 @@ use std::{borrow::Cow, cell::RefCell, env, io};
 
 use log::{LevelFilter, Log, Metadata, Record, SetLoggerError};
 
-use crate::filter;
-use crate::filter::Filter;
 use crate::fmt;
 use crate::fmt::writer::{self, Writer};
 use crate::fmt::{FormatFn, Formatter};
@@ -38,7 +36,7 @@ pub const DEFAULT_WRITE_STYLE_ENV: &str = "RUST_LOG_STYLE";
 /// ```
 #[derive(Default)]
 pub struct Builder {
-    filter: filter::Builder,
+    filter: env_filter::Builder,
     writer: writer::Builder,
     format: fmt::Builder,
     built: bool,
@@ -532,7 +530,7 @@ impl std::fmt::Debug for Builder {
 /// [`Builder`]: struct.Builder.html
 pub struct Logger {
     writer: Writer,
-    filter: Filter,
+    filter: env_filter::Filter,
     format: FormatFn,
 }
 

From 2d3526001061bacbf4a4c47767a318986c2c61b0 Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Fri, 19 Jan 2024 11:48:20 -0600
Subject: [PATCH 24/28] feat(filter): Add a Logger decorator

---
 crates/env_filter/src/filtered_log.rs | 45 +++++++++++++++++++++++++++
 crates/env_filter/src/lib.rs          | 39 +++++++++--------------
 2 files changed, 59 insertions(+), 25 deletions(-)
 create mode 100644 crates/env_filter/src/filtered_log.rs

diff --git a/crates/env_filter/src/filtered_log.rs b/crates/env_filter/src/filtered_log.rs
new file mode 100644
index 00000000..f707bcc3
--- /dev/null
+++ b/crates/env_filter/src/filtered_log.rs
@@ -0,0 +1,45 @@
+use log::Log;
+
+use crate::Filter;
+
+/// Decorate a [`log::Log`] with record [`Filter`]ing.
+///
+/// Records that match the filter will be forwarded to the wrapped log.
+/// Other records will be ignored.
+#[derive(Debug)]
+pub struct FilteredLog<T> {
+    log: T,
+    filter: Filter,
+}
+
+impl<T: Log> FilteredLog<T> {
+    /// Create a new filtered log.
+    pub fn new(log: T, filter: Filter) -> Self {
+        Self { log, filter }
+    }
+}
+
+impl<T: Log> Log for FilteredLog<T> {
+    /// Determines if a log message with the specified metadata would be logged.
+    ///
+    /// For the wrapped log, this returns `true` only if both the filter and the wrapped log return `true`.
+    fn enabled(&self, metadata: &log::Metadata) -> bool {
+        self.filter.enabled(metadata) && self.log.enabled(metadata)
+    }
+
+    /// Logs the record.
+    ///
+    /// Forwards the record to the wrapped log, but only if the record matches the filter.
+    fn log(&self, record: &log::Record) {
+        if self.filter.matches(record) {
+            self.log.log(record)
+        }
+    }
+
+    /// Flushes any buffered records.
+    ///
+    /// Forwards directly to the wrapped log.
+    fn flush(&self) {
+        self.log.flush()
+    }
+}
diff --git a/crates/env_filter/src/lib.rs b/crates/env_filter/src/lib.rs
index 494b82da..dad06817 100644
--- a/crates/env_filter/src/lib.rs
+++ b/crates/env_filter/src/lib.rs
@@ -14,44 +14,32 @@
 //! use env_filter::Filter;
 //! use log::{Log, Metadata, Record};
 //!
-//! struct MyLogger {
-//!     filter: Filter
-//! }
-//!
-//! impl MyLogger {
-//!     fn new() -> MyLogger {
-//!         use env_filter::Builder;
-//!         let mut builder = Builder::new();
-//!
-//!         // Parse a directives string from an environment variable
-//!         if let Ok(ref filter) = std::env::var("MY_LOG_LEVEL") {
-//!            builder.parse(filter);
-//!         }
+//! struct PrintLogger;
 //!
-//!         MyLogger {
-//!             filter: builder.build()
-//!         }
-//!     }
-//! }
-//!
-//! impl Log for MyLogger {
+//! impl Log for PrintLogger {
 //!     fn enabled(&self, metadata: &Metadata) -> bool {
-//!         self.filter.enabled(metadata)
+//!         true
 //!     }
 //!
 //!     fn log(&self, record: &Record) {
-//!         // Check if the record is matched by the filter
-//!         if self.filter.matches(record) {
-//!             println!("{:?}", record);
-//!         }
+//!         println!("{:?}", record);
 //!     }
 //!
 //!     fn flush(&self) {}
 //! }
+//!
+//! let mut builder = env_filter::Builder::new();
+//! // Parse a directives string from an environment variable
+//! if let Ok(ref filter) = std::env::var("MY_LOG_LEVEL") {
+//!     builder.parse(filter);
+//! }
+//!
+//! let logger = env_filter::FilteredLog::new(PrintLogger, builder.build());
 //! ```
 
 mod directive;
 mod filter;
+mod filtered_log;
 mod op;
 mod parser;
 
@@ -62,3 +50,4 @@ use parser::parse_spec;
 
 pub use filter::Builder;
 pub use filter::Filter;
+pub use filtered_log::FilteredLog;

From 6c2ea8028236fe80c1da0a354b19808bf440858d Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Fri, 19 Jan 2024 11:50:52 -0600
Subject: [PATCH 25/28] style(filter): Clean up

---
 crates/env_filter/src/filter.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crates/env_filter/src/filter.rs b/crates/env_filter/src/filter.rs
index 7a052720..c5d107da 100644
--- a/crates/env_filter/src/filter.rs
+++ b/crates/env_filter/src/filter.rs
@@ -5,9 +5,9 @@ use std::mem;
 use log::{LevelFilter, Metadata, Record};
 
 use crate::enabled;
+use crate::parse_spec;
 use crate::Directive;
 use crate::FilterOp;
-use crate::parse_spec;
 
 /// A builder for a log filter.
 ///

From 5e226cb2b73d6c9f1b21886a4b504afdea1ebfcf Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Fri, 19 Jan 2024 11:59:56 -0600
Subject: [PATCH 26/28] chore: Release

---
 crates/env_filter/CHANGELOG.md | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/crates/env_filter/CHANGELOG.md b/crates/env_filter/CHANGELOG.md
index 78e2e120..b9a276ca 100644
--- a/crates/env_filter/CHANGELOG.md
+++ b/crates/env_filter/CHANGELOG.md
@@ -7,5 +7,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 <!-- next-header -->
 ## [Unreleased] - ReleaseDate
 
+## [0.1.0] - 2024-01-19
+
 <!-- next-url -->
-[Unreleased]: https://github.com/rust-cli/env_logger/compare/b4a2c304c16d1db4a2998f24c00e00c0f776113b...HEAD
+[Unreleased]: https://github.com/rust-cli/env_logger/compare/env_filter-v0.1.0...HEAD
+[0.1.0]: https://github.com/rust-cli/env_logger/compare/b4a2c304c16d1db4a2998f24c00e00c0f776113b...env_filter-v0.1.0

From ba41ebb6d2d726403560cd987b1c5b3c6797f817 Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Fri, 19 Jan 2024 12:07:14 -0600
Subject: [PATCH 27/28] docs: Update changelog

---
 CHANGELOG.md | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6b911e5e..93b9369e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,30 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 <!-- next-header -->
 ## [Unreleased] - ReleaseDate
 
+### Breaking Change
+
+- Removed bespoke styling API
+  - `env_logger::fmt::Formatter::style`
+  - `env_logger::fmt::Formatter::default_styled_level`
+  - `env_logger::fmt::Style`
+  - `env_logger::fmt::Color`
+  - `env_logger::fmt::StyledValue`
+- Removed `env_logger::filter` in favor of `env_filter`
+
+### Compatibility
+
+MSRV changed to 1.71
+
+### Features
+
+- Automatically adapt ANSI escape codes in logged messages to the current terminal's capabilities
+- Add support for `NO_COLOR` and `CLICOLOR_FORCE`, see https://bixense.com/clicolors/
+
+### Fixes
+
+- Print colors when `is_test(true)`
+- Allow styling with `Target::Pipe`
+
 ## [0.10.2] - 2024-01-18
 
 ### Performance

From 8f4361ba4439acb69068be0e181d2d1300b7218d Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Fri, 19 Jan 2024 12:08:36 -0600
Subject: [PATCH 28/28] chore: Release

---
 CHANGELOG.md | 5 ++++-
 Cargo.lock   | 2 +-
 Cargo.toml   | 2 +-
 3 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 93b9369e..e3f20a27 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 <!-- next-header -->
 ## [Unreleased] - ReleaseDate
 
+## [0.11.0] - 2024-01-19
+
 ### Breaking Change
 
 - Removed bespoke styling API
@@ -85,7 +87,8 @@ To open room for changing dependencies:
 - Added a method to print the module instead of the target
 
 <!-- next-url -->
-[Unreleased]: https://github.com/rust-cli/env_logger/compare/v0.10.2...HEAD
+[Unreleased]: https://github.com/rust-cli/env_logger/compare/v0.11.0...HEAD
+[0.11.0]: https://github.com/rust-cli/env_logger/compare/v0.10.2...v0.11.0
 [0.10.2]: https://github.com/rust-cli/env_logger/compare/v0.10.1...v0.10.2
 [0.10.1]: https://github.com/rust-cli/env_logger/compare/v0.10.0...v0.10.1
 [0.10.0]: https://github.com/rust-cli/env_logger/compare/v0.9.3...v0.10.0
diff --git a/Cargo.lock b/Cargo.lock
index 776d3400..204d2c4c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -81,7 +81,7 @@ dependencies = [
 
 [[package]]
 name = "env_logger"
-version = "0.10.2"
+version = "0.11.0"
 dependencies = [
  "anstream",
  "anstyle",
diff --git a/Cargo.toml b/Cargo.toml
index b669cef6..224c6659 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -20,7 +20,7 @@ include = [
 
 [package]
 name = "env_logger"
-version = "0.10.2"
+version = "0.11.0"
 description = """
 A logging implementation for `log` which is configured via an environment
 variable.

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