Add back async_trait to GenericClient interface

bikeshedder · bikeshedder · commit d75243341b90 · 2024-06-04T15:35:42.000Z
diff --git a/postgres/CHANGELOG.md b/postgres/CHANGELOG.md
@@ -9,6 +9,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+- Add back `async_trait` to the `GenericClient` trait.
+  The removal of `async_trait` caused some errors for code using
+  the generic client interface. A test was added to ensure future
+  removals of `async_trait` will not cause this code to break.
+
 ## [0.13.2] - 2024-05-07
 
 - Add WASM support
diff --git a/postgres/Cargo.toml b/postgres/Cargo.toml
@@ -20,6 +20,7 @@ rt_async-std_1 = ["deadpool/rt_async-std_1"]
 serde = ["deadpool/serde", "dep:serde"]
 
 [dependencies]
+async-trait = "0.1.80"
 deadpool = { path = "../", version = "0.12.0", default-features = false, features = [
     "managed",
 ] }
diff --git a/postgres/src/generic_client.rs b/postgres/src/generic_client.rs
@@ -3,12 +3,12 @@
 //! - The `client()` method is not available.
 //! - The `prepare_cached()` and `prepare_typed_cached()` are
 //!   added.
-use std::future::Future;
-
 use tokio_postgres::types::{BorrowToSql, ToSql, Type};
 use tokio_postgres::RowStream;
 use tokio_postgres::{Error, Row, Statement, ToStatement};
 
+use async_trait::async_trait;
+
 use crate::{Client, ClientWrapper, Transaction};
 
 mod private {
@@ -18,96 +18,78 @@ mod private {
 /// A trait allowing abstraction over connections and transactions.
 ///
 /// This trait is "sealed", and cannot be implemented outside of this crate.
+#[async_trait]
 pub trait GenericClient: Sync + private::Sealed {
     /// Like `Client::execute`.
-    fn execute<T>(
-        &self,
-        query: &T,
-        params: &[&(dyn ToSql + Sync)],
-    ) -> impl Future<Output = Result<u64, Error>> + Send
+    async fn execute<T>(&self, query: &T, params: &[&(dyn ToSql + Sync)]) -> Result<u64, Error>
     where
         T: ?Sized + ToStatement + Sync + Send;
 
     /// Like `Client::execute_raw`.
-    fn execute_raw<P, I, T>(
-        &self,
-        statement: &T,
-        params: I,
-    ) -> impl Future<Output = Result<u64, Error>> + Send
+    async fn execute_raw<P, I, T>(&self, statement: &T, params: I) -> Result<u64, Error>
     where
         T: ?Sized + ToStatement + Sync + Send,
         P: BorrowToSql,
         I: IntoIterator<Item = P> + Sync + Send,
         I::IntoIter: ExactSizeIterator;
 
     /// Like `Client::query`.
-    fn query<T>(
-        &self,
-        query: &T,
-        params: &[&(dyn ToSql + Sync)],
-    ) -> impl Future<Output = Result<Vec<Row>, Error>> + Send
+    async fn query<T>(&self, query: &T, params: &[&(dyn ToSql + Sync)]) -> Result<Vec<Row>, Error>
     where
         T: ?Sized + ToStatement + Sync + Send;
 
     /// Like `Client::query_one`.
-    fn query_one<T>(
+    async fn query_one<T>(
         &self,
         statement: &T,
         params: &[&(dyn ToSql + Sync)],
-    ) -> impl Future<Output = Result<Row, Error>> + Send
+    ) -> Result<Row, Error>
     where
         T: ?Sized + ToStatement + Sync + Send;
 
     /// Like `Client::query_opt`.
-    fn query_opt<T>(
+    async fn query_opt<T>(
         &self,
         statement: &T,
         params: &[&(dyn ToSql + Sync)],
-    ) -> impl Future<Output = Result<Option<Row>, Error>> + Send
+    ) -> Result<Option<Row>, Error>
     where
         T: ?Sized + ToStatement + Sync + Send;
 
     /// Like `Client::query_raw`.
-    fn query_raw<T, P, I>(
-        &self,
-        statement: &T,
-        params: I,
-    ) -> impl Future<Output = Result<RowStream, Error>> + Send
+    async fn query_raw<T, P, I>(&self, statement: &T, params: I) -> Result<RowStream, Error>
     where
         T: ?Sized + ToStatement + Sync + Send,
         P: BorrowToSql,
         I: IntoIterator<Item = P> + Sync + Send,
         I::IntoIter: ExactSizeIterator;
 
     /// Like `Client::prepare`.
-    fn prepare(&self, query: &str) -> impl Future<Output = Result<Statement, Error>> + Send;
+    async fn prepare(&self, query: &str) -> Result<Statement, Error>;
 
     /// Like `Client::prepare_typed`.
-    fn prepare_typed(
+    async fn prepare_typed(
         &self,
         query: &str,
         parameter_types: &[Type],
-    ) -> impl Future<Output = Result<Statement, Error>> + Send;
+    ) -> Result<Statement, Error>;
 
     /// Like [`Client::prepare_cached`].
-    fn prepare_cached(&self, query: &str) -> impl Future<Output = Result<Statement, Error>> + Send;
+    async fn prepare_cached(&self, query: &str) -> Result<Statement, Error>;
 
     /// Like [`Client::prepare_typed_cached`]
-    fn prepare_typed_cached(
-        &self,
-        query: &str,
-        types: &[Type],
-    ) -> impl Future<Output = Result<Statement, Error>> + Send;
+    async fn prepare_typed_cached(&self, query: &str, types: &[Type]) -> Result<Statement, Error>;
 
     /// Like `Client::transaction`.
-    fn transaction(&mut self) -> impl Future<Output = Result<Transaction<'_>, Error>> + Send;
+    async fn transaction(&mut self) -> Result<Transaction<'_>, Error>;
 
     /// Like `Client::batch_execute`.
-    fn batch_execute(&self, query: &str) -> impl Future<Output = Result<(), Error>> + Send;
+    async fn batch_execute(&self, query: &str) -> Result<(), Error>;
 }
 
 impl private::Sealed for Client {}
 
+#[async_trait]
 impl GenericClient for Client {
     async fn execute<T>(&self, query: &T, params: &[&(dyn ToSql + Sync)]) -> Result<u64, Error>
     where
@@ -196,6 +178,7 @@ impl GenericClient for Client {
 
 impl private::Sealed for Transaction<'_> {}
 
+#[async_trait]
 #[allow(clippy::needless_lifetimes)]
 impl GenericClient for Transaction<'_> {
     async fn execute<T>(&self, query: &T, params: &[&(dyn ToSql + Sync)]) -> Result<u64, Error>
