From f36817108a7399defbc9a29508d25e1419cae745 Mon Sep 17 00:00:00 2001
From: Josh Goldberg <git@joshuakgoldberg.com>
Date: Thu, 3 Jul 2025 14:55:45 -0400
Subject: [PATCH 01/13] feat(typescript-estree): infer tsconfigRootDir from
 call stack

---
 .../src/getRootDirFromStack.ts                | 16 ++++++++
 packages/typescript-eslint/src/index.ts       | 34 +++++++++++++++-
 .../tests/getRootDirFromStack.test.ts         | 32 +++++++++++++++
 .../typescript-eslint/tsconfig.build.json     |  3 ++
 packages/typescript-eslint/tsconfig.json      |  3 ++
 .../typescript-estree/src/clear-caches.ts     |  2 +
 packages/typescript-estree/src/index.ts       |  1 +
 .../candidateTSConfigRootDirs.ts              | 30 ++++++++++++++
 .../src/parseSettings/createParseSettings.ts  |  3 +-
 .../lib/candidateTSConfigRootDirs.test.ts     | 39 +++++++++++++++++++
 .../tests/lib/createParseSettings.test.ts     | 36 +++++++++++++++++
 11 files changed, 196 insertions(+), 3 deletions(-)
 create mode 100644 packages/typescript-eslint/src/getRootDirFromStack.ts
 create mode 100644 packages/typescript-eslint/tests/getRootDirFromStack.test.ts
 create mode 100644 packages/typescript-estree/src/parseSettings/candidateTSConfigRootDirs.ts
 create mode 100644 packages/typescript-estree/tests/lib/candidateTSConfigRootDirs.test.ts

diff --git a/packages/typescript-eslint/src/getRootDirFromStack.ts b/packages/typescript-eslint/src/getRootDirFromStack.ts
new file mode 100644
index 000000000000..25d87fb4f992
--- /dev/null
+++ b/packages/typescript-eslint/src/getRootDirFromStack.ts
@@ -0,0 +1,16 @@
+import { fileURLToPath } from 'node:url';
+
+export function getRootDirFromStack(stack: string): string | undefined {
+  for (const line of stack.split('\n').map(line => line.trim())) {
+    const candidate = /(\S+)eslint\.config\.(c|m)?(j|t)s/.exec(line)?.[1];
+    if (!candidate) {
+      continue;
+    }
+
+    return candidate.startsWith('file://')
+      ? fileURLToPath(candidate)
+      : candidate;
+  }
+
+  return undefined;
+}
diff --git a/packages/typescript-eslint/src/index.ts b/packages/typescript-eslint/src/index.ts
index 86870c855cd0..2de6143d0b7a 100644
--- a/packages/typescript-eslint/src/index.ts
+++ b/packages/typescript-eslint/src/index.ts
@@ -3,8 +3,10 @@ import type { TSESLint } from '@typescript-eslint/utils';
 
 import pluginBase from '@typescript-eslint/eslint-plugin';
 import rawPlugin from '@typescript-eslint/eslint-plugin/use-at-your-own-risk/raw-plugin';
+import { addCandidateTSConfigRootDir } from '@typescript-eslint/typescript-estree';
 
 import { config } from './config-helper';
+import { getRootDirFromStack } from './getRootDirFromStack';
 
 export const parser: TSESLint.FlatConfig.Parser = rawPlugin.parser;
 
@@ -36,7 +38,7 @@ export const plugin: TSESLint.FlatConfig.Plugin = pluginBase as Omit<
   'configs'
 >;
 
-export const configs = {
+export const configs = createConfigsGetters({
   /**
    * Enables each the rules provided as a part of typescript-eslint. Note that many rules are not applicable in all codebases, or are meant to be configured.
    * @see {@link https://typescript-eslint.io/users/configs#all}
@@ -120,7 +122,35 @@ export const configs = {
    */
   stylisticTypeCheckedOnly:
     rawPlugin.flatConfigs['flat/stylistic-type-checked-only'],
-};
+});
+
+function createConfigsGetters<T extends object>(values: T): T {
+  const configs = {};
+
+  Object.defineProperties(
+    configs,
+    Object.fromEntries(
+      Object.entries(values).map(([key, value]: [string, unknown]) => [
+        key,
+        {
+          get: () => {
+            const candidateRootDir = getRootDirFromStack(
+              // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+              new Error().stack!,
+            );
+            if (candidateRootDir) {
+              addCandidateTSConfigRootDir(candidateRootDir);
+            }
+
+            return value;
+          },
+        },
+      ]),
+    ),
+  );
+
+  return configs as T;
+}
 
 export type Config = TSESLint.FlatConfig.ConfigFile;
 
diff --git a/packages/typescript-eslint/tests/getRootDirFromStack.test.ts b/packages/typescript-eslint/tests/getRootDirFromStack.test.ts
new file mode 100644
index 000000000000..293a0cfa27a0
--- /dev/null
+++ b/packages/typescript-eslint/tests/getRootDirFromStack.test.ts
@@ -0,0 +1,32 @@
+import { getRootDirFromStack } from '../src/getRootDirFromStack';
+
+describe(getRootDirFromStack, () => {
+  it('returns undefined when no file path seems to be an ESLint config', () => {
+    const actual = getRootDirFromStack(
+      [
+        `Error`,
+        ' at file:///index.js',
+        ' at ModuleJob.run',
+        'at async NodeHfs.walk(...)',
+      ].join('\n'),
+    );
+
+    expect(actual).toBeUndefined();
+  });
+
+  it.each(['cjs', 'cts', 'js', 'mjs', 'mts', 'ts'])(
+    'returns the path to the config file when in a Unix system and its extension is %s',
+    extension => {
+      const actual = getRootDirFromStack(
+        [
+          `Error`,
+          ` at file:///path/to/file/eslint.config.${extension}`,
+          ' at ModuleJob.run',
+          'at async NodeHfs.walk(...)',
+        ].join('\n'),
+      );
+
+      expect(actual).toBe('/path/to/file/');
+    },
+  );
+});
diff --git a/packages/typescript-eslint/tsconfig.build.json b/packages/typescript-eslint/tsconfig.build.json
index c41d1d4c30ed..8f377becd3cd 100644
--- a/packages/typescript-eslint/tsconfig.build.json
+++ b/packages/typescript-eslint/tsconfig.build.json
@@ -2,6 +2,9 @@
   "extends": "../../tsconfig.build.json",
   "compilerOptions": {},
   "references": [
+    {
+      "path": "../typescript-estree/tsconfig.build.json"
+    },
     {
       "path": "../utils/tsconfig.build.json"
     },
diff --git a/packages/typescript-eslint/tsconfig.json b/packages/typescript-eslint/tsconfig.json
index d12794a533bf..f94f467e0b00 100644
--- a/packages/typescript-eslint/tsconfig.json
+++ b/packages/typescript-eslint/tsconfig.json
@@ -3,6 +3,9 @@
   "files": [],
   "include": [],
   "references": [
+    {
+      "path": "../typescript-estree"
+    },
     {
       "path": "../utils"
     },
diff --git a/packages/typescript-estree/src/clear-caches.ts b/packages/typescript-estree/src/clear-caches.ts
index 5e9867d3beab..3d5897953b70 100644
--- a/packages/typescript-estree/src/clear-caches.ts
+++ b/packages/typescript-estree/src/clear-caches.ts
@@ -3,6 +3,7 @@ import {
   clearDefaultProjectMatchedFiles,
   clearProgramCache as clearProgramCacheOriginal,
 } from './parser';
+import { clearCandidateTSConfigRootDirs } from './parseSettings/candidateTSConfigRootDirs';
 import {
   clearTSConfigMatchCache,
   clearTSServerProjectService,
@@ -17,6 +18,7 @@ import { clearGlobCache } from './parseSettings/resolveProjectList';
  * - In custom lint tooling that iteratively lints one project at a time to prevent OOMs.
  */
 export function clearCaches(): void {
+  clearCandidateTSConfigRootDirs();
   clearDefaultProjectMatchedFiles();
   clearProgramCacheOriginal();
   clearWatchCaches();
diff --git a/packages/typescript-estree/src/index.ts b/packages/typescript-estree/src/index.ts
index 39e921e8762a..a3beef50759c 100644
--- a/packages/typescript-estree/src/index.ts
+++ b/packages/typescript-estree/src/index.ts
@@ -16,6 +16,7 @@ export type {
   ParserServicesWithTypeInformation,
   TSESTreeOptions,
 } from './parser-options';
+export { addCandidateTSConfigRootDir } from './parseSettings/candidateTSConfigRootDirs';
 export { simpleTraverse } from './simple-traverse';
 export * from './ts-estree';
 export { typescriptVersionIsAtLeast } from './version-check';
diff --git a/packages/typescript-estree/src/parseSettings/candidateTSConfigRootDirs.ts b/packages/typescript-estree/src/parseSettings/candidateTSConfigRootDirs.ts
new file mode 100644
index 000000000000..37b38dc1b435
--- /dev/null
+++ b/packages/typescript-estree/src/parseSettings/candidateTSConfigRootDirs.ts
@@ -0,0 +1,30 @@
+const candidateTSConfigRootDirs = new Set<string>();
+
+export function addCandidateTSConfigRootDir(candidate: string): void {
+  candidateTSConfigRootDirs.add(candidate);
+}
+
+export function clearCandidateTSConfigRootDirs(): void {
+  candidateTSConfigRootDirs.clear();
+}
+
+export function getInferredTSConfigRootDir(): string {
+  const entries = [...candidateTSConfigRootDirs];
+
+  switch (entries.length) {
+    case 0:
+      return process.cwd();
+
+    case 1:
+      return entries[0];
+
+    default:
+      throw new Error(
+        [
+          'No tsconfigRootDir was set, and multiple candidate TSConfigRootDirs are present:',
+          ...entries.map(candidate => ` - ${candidate}`),
+          "You'll need to explicitly set tsconfigRootDir in your parser options.",
+        ].join('\n'),
+      );
+  }
+}
diff --git a/packages/typescript-estree/src/parseSettings/createParseSettings.ts b/packages/typescript-estree/src/parseSettings/createParseSettings.ts
index 678b771ac3a5..6710e36b870f 100644
--- a/packages/typescript-estree/src/parseSettings/createParseSettings.ts
+++ b/packages/typescript-estree/src/parseSettings/createParseSettings.ts
@@ -15,6 +15,7 @@ import type { MutableParseSettings } from './index';
 import { ensureAbsolutePath } from '../create-program/shared';
 import { validateDefaultProjectForFilesGlob } from '../create-program/validateDefaultProjectForFilesGlob';
 import { isSourceFile } from '../source-files';
+import { getInferredTSConfigRootDir } from './candidateTSConfigRootDirs';
 import {
   DEFAULT_TSCONFIG_CACHE_DURATION_SECONDS,
   ExpiringCache,
@@ -52,7 +53,7 @@ export function createParseSettings(
   const tsconfigRootDir =
     typeof tsestreeOptions.tsconfigRootDir === 'string'
       ? tsestreeOptions.tsconfigRootDir
-      : process.cwd();
+      : getInferredTSConfigRootDir();
   const passedLoggerFn = typeof tsestreeOptions.loggerFn === 'function';
   const filePath = ensureAbsolutePath(
     typeof tsestreeOptions.filePath === 'string' &&
diff --git a/packages/typescript-estree/tests/lib/candidateTSConfigRootDirs.test.ts b/packages/typescript-estree/tests/lib/candidateTSConfigRootDirs.test.ts
new file mode 100644
index 000000000000..9f59d6f507f9
--- /dev/null
+++ b/packages/typescript-estree/tests/lib/candidateTSConfigRootDirs.test.ts
@@ -0,0 +1,39 @@
+import { addCandidateTSConfigRootDir } from '../../src';
+import {
+  clearCandidateTSConfigRootDirs,
+  getInferredTSConfigRootDir,
+} from '../../src/parseSettings/candidateTSConfigRootDirs';
+
+describe(getInferredTSConfigRootDir, () => {
+  beforeEach(() => {
+    clearCandidateTSConfigRootDirs();
+  });
+
+  it('returns process.cwd() when there are no candidates', () => {
+    const actual = getInferredTSConfigRootDir();
+
+    expect(actual).toBe(process.cwd());
+  });
+
+  it('returns the candidate when there is one candidate', () => {
+    const candidate = 'a/b/c';
+    addCandidateTSConfigRootDir(candidate);
+
+    const actual = getInferredTSConfigRootDir();
+
+    expect(actual).toBe(candidate);
+  });
+
+  it('throws an error when there are multiple candidates', () => {
+    addCandidateTSConfigRootDir('a');
+    addCandidateTSConfigRootDir('b');
+
+    expect(() => getInferredTSConfigRootDir())
+      .toThrowErrorMatchingInlineSnapshot(`
+      [Error: No tsconfigRootDir was set, and multiple candidate TSConfigRootDirs are present:
+       - a
+       - b
+      You'll need to explicitly set tsconfigRootDir in your parser options.]
+    `);
+  });
+});
diff --git a/packages/typescript-estree/tests/lib/createParseSettings.test.ts b/packages/typescript-estree/tests/lib/createParseSettings.test.ts
index ccb210fd8dbd..d3f5fea99819 100644
--- a/packages/typescript-estree/tests/lib/createParseSettings.test.ts
+++ b/packages/typescript-estree/tests/lib/createParseSettings.test.ts
@@ -1,3 +1,7 @@
+import {
+  addCandidateTSConfigRootDir,
+  clearCandidateTSConfigRootDirs,
+} from '../../src/parseSettings/candidateTSConfigRootDirs';
 import { createParseSettings } from '../../src/parseSettings/createParseSettings';
 
 const projectService = { service: true };
@@ -61,4 +65,36 @@ describe(createParseSettings, () => {
       );
     });
   });
+
+  describe('tsconfigRootDir', () => {
+    beforeEach(() => {
+      clearCandidateTSConfigRootDirs();
+    });
+
+    it('uses the provided tsconfigRootDir when it exists and no candidates exist', () => {
+      const tsconfigRootDir = 'a/b/c';
+
+      const parseSettings = createParseSettings('', { tsconfigRootDir });
+
+      expect(parseSettings.tsconfigRootDir).toBe(tsconfigRootDir);
+    });
+
+    it('uses the provided tsconfigRootDir when it exists and a candidate exists', () => {
+      addCandidateTSConfigRootDir('candidate');
+      const tsconfigRootDir = 'a/b/c';
+
+      const parseSettings = createParseSettings('', { tsconfigRootDir });
+
+      expect(parseSettings.tsconfigRootDir).toBe(tsconfigRootDir);
+    });
+
+    it('uses the inferred candidate when no tsconfigRootDir is provided and a candidate exists', () => {
+      const tsconfigRootDir = 'a/b/c';
+      addCandidateTSConfigRootDir(tsconfigRootDir);
+
+      const parseSettings = createParseSettings('');
+
+      expect(parseSettings.tsconfigRootDir).toBe(tsconfigRootDir);
+    });
+  });
 });

From 88edcc3fcbd81301d7d143251e9285715de6df3d Mon Sep 17 00:00:00 2001
From: Josh Goldberg <git@joshuakgoldberg.com>
Date: Thu, 3 Jul 2025 15:41:01 -0400
Subject: [PATCH 02/13] rename

---
 ...RootDirFromStack.ts => getTsconfigRootDirFromStack.ts} | 2 +-
 packages/typescript-eslint/src/index.ts                   | 4 ++--
 ...mStack.test.ts => getTsconfigRootDirFromStack.test.ts} | 8 ++++----
 3 files changed, 7 insertions(+), 7 deletions(-)
 rename packages/typescript-eslint/src/{getRootDirFromStack.ts => getTsconfigRootDirFromStack.ts} (81%)
 rename packages/typescript-eslint/tests/{getRootDirFromStack.test.ts => getTsconfigRootDirFromStack.test.ts} (75%)

diff --git a/packages/typescript-eslint/src/getRootDirFromStack.ts b/packages/typescript-eslint/src/getTsconfigRootDirFromStack.ts
similarity index 81%
rename from packages/typescript-eslint/src/getRootDirFromStack.ts
rename to packages/typescript-eslint/src/getTsconfigRootDirFromStack.ts
index 25d87fb4f992..7cc4e87a66fd 100644
--- a/packages/typescript-eslint/src/getRootDirFromStack.ts
+++ b/packages/typescript-eslint/src/getTsconfigRootDirFromStack.ts
@@ -1,6 +1,6 @@
 import { fileURLToPath } from 'node:url';
 
-export function getRootDirFromStack(stack: string): string | undefined {
+export function getTsconfigRootDirFromStack(stack: string): string | undefined {
   for (const line of stack.split('\n').map(line => line.trim())) {
     const candidate = /(\S+)eslint\.config\.(c|m)?(j|t)s/.exec(line)?.[1];
     if (!candidate) {
diff --git a/packages/typescript-eslint/src/index.ts b/packages/typescript-eslint/src/index.ts
index 2de6143d0b7a..91ac90534ccb 100644
--- a/packages/typescript-eslint/src/index.ts
+++ b/packages/typescript-eslint/src/index.ts
@@ -6,7 +6,7 @@ import rawPlugin from '@typescript-eslint/eslint-plugin/use-at-your-own-risk/raw
 import { addCandidateTSConfigRootDir } from '@typescript-eslint/typescript-estree';
 
 import { config } from './config-helper';
-import { getRootDirFromStack } from './getRootDirFromStack';
+import { getTsconfigRootDirFromStack } from './getTsconfigRootDirFromStack';
 
 export const parser: TSESLint.FlatConfig.Parser = rawPlugin.parser;
 
@@ -134,7 +134,7 @@ function createConfigsGetters<T extends object>(values: T): T {
         key,
         {
           get: () => {
-            const candidateRootDir = getRootDirFromStack(
+            const candidateRootDir = getTsconfigRootDirFromStack(
               // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
               new Error().stack!,
             );
diff --git a/packages/typescript-eslint/tests/getRootDirFromStack.test.ts b/packages/typescript-eslint/tests/getTsconfigRootDirFromStack.test.ts
similarity index 75%
rename from packages/typescript-eslint/tests/getRootDirFromStack.test.ts
rename to packages/typescript-eslint/tests/getTsconfigRootDirFromStack.test.ts
index 293a0cfa27a0..63766760984e 100644
--- a/packages/typescript-eslint/tests/getRootDirFromStack.test.ts
+++ b/packages/typescript-eslint/tests/getTsconfigRootDirFromStack.test.ts
@@ -1,8 +1,8 @@
-import { getRootDirFromStack } from '../src/getRootDirFromStack';
+import { getTsconfigRootDirFromStack } from '../src/getTsconfigRootDirFromStack';
 
-describe(getRootDirFromStack, () => {
+describe(getTsconfigRootDirFromStack, () => {
   it('returns undefined when no file path seems to be an ESLint config', () => {
-    const actual = getRootDirFromStack(
+    const actual = getTsconfigRootDirFromStack(
       [
         `Error`,
         ' at file:///index.js',
@@ -17,7 +17,7 @@ describe(getRootDirFromStack, () => {
   it.each(['cjs', 'cts', 'js', 'mjs', 'mts', 'ts'])(
     'returns the path to the config file when in a Unix system and its extension is %s',
     extension => {
-      const actual = getRootDirFromStack(
+      const actual = getTsconfigRootDirFromStack(
         [
           `Error`,
           ` at file:///path/to/file/eslint.config.${extension}`,

From c42ce4ca985ef53dd501fb8e21e5881610908af8 Mon Sep 17 00:00:00 2001
From: Josh Goldberg <git@joshuakgoldberg.com>
Date: Fri, 4 Jul 2025 07:45:48 -0500
Subject: [PATCH 03/13] Adjust for Windows

---
 .../tests/getTsconfigRootDirFromStack.test.ts        | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/packages/typescript-eslint/tests/getTsconfigRootDirFromStack.test.ts b/packages/typescript-eslint/tests/getTsconfigRootDirFromStack.test.ts
index 63766760984e..ffbbd94e3448 100644
--- a/packages/typescript-eslint/tests/getTsconfigRootDirFromStack.test.ts
+++ b/packages/typescript-eslint/tests/getTsconfigRootDirFromStack.test.ts
@@ -1,3 +1,4 @@
+import path from 'node:path';
 import { getTsconfigRootDirFromStack } from '../src/getTsconfigRootDirFromStack';
 
 describe(getTsconfigRootDirFromStack, () => {
@@ -15,18 +16,23 @@ describe(getTsconfigRootDirFromStack, () => {
   });
 
   it.each(['cjs', 'cts', 'js', 'mjs', 'mts', 'ts'])(
-    'returns the path to the config file when in a Unix system and its extension is %s',
+    'returns the path to the config file when in a Posix system and its extension is %s',
     extension => {
+      const expected =
+        process.platform === 'win32'
+          ? 'C:\\path\\to\\file\\'
+          : '/path/to/file/';
+
       const actual = getTsconfigRootDirFromStack(
         [
           `Error`,
-          ` at file:///path/to/file/eslint.config.${extension}`,
+          ` at ${path.join(expected, `eslint.config.${extension}`)}`,
           ' at ModuleJob.run',
           'at async NodeHfs.walk(...)',
         ].join('\n'),
       );
 
-      expect(actual).toBe('/path/to/file/');
+      expect(actual).toBe(expected);
     },
   );
 });

From 2856485cf14ee9b9d43570f73b2117ac7d6b5dc4 Mon Sep 17 00:00:00 2001
From: Josh Goldberg <git@joshuakgoldberg.com>
Date: Fri, 4 Jul 2025 09:02:49 -0400
Subject: [PATCH 04/13] lint

---
 .../tests/getTsconfigRootDirFromStack.test.ts |  1 +
 packages/website/data/recent-blog-posts.json  | 23 +++++++++++++++++++
 2 files changed, 24 insertions(+)
 create mode 100644 packages/website/data/recent-blog-posts.json

diff --git a/packages/typescript-eslint/tests/getTsconfigRootDirFromStack.test.ts b/packages/typescript-eslint/tests/getTsconfigRootDirFromStack.test.ts
index ffbbd94e3448..3f1ca139b301 100644
--- a/packages/typescript-eslint/tests/getTsconfigRootDirFromStack.test.ts
+++ b/packages/typescript-eslint/tests/getTsconfigRootDirFromStack.test.ts
@@ -1,4 +1,5 @@
 import path from 'node:path';
+
 import { getTsconfigRootDirFromStack } from '../src/getTsconfigRootDirFromStack';
 
 describe(getTsconfigRootDirFromStack, () => {
diff --git a/packages/website/data/recent-blog-posts.json b/packages/website/data/recent-blog-posts.json
new file mode 100644
index 000000000000..9bc0ece682e5
--- /dev/null
+++ b/packages/website/data/recent-blog-posts.json
@@ -0,0 +1,23 @@
+[
+  {
+    "date": "2025-05-29T00:00:00.000Z",
+    "description": "How typescript-eslint's new \"Project Service\" makes typed linting easier to configure, especially for large projects.",
+    "readingTime": 7,
+    "slug": "project-service",
+    "title": "Typed Linting with Project Service"
+  },
+  {
+    "date": "2025-01-21T00:00:00.000Z",
+    "description": "How typescript-eslint expands on TypeScript's type safety to catch explicit and implicit `any`s.",
+    "readingTime": 9,
+    "slug": "avoiding-anys",
+    "title": "Avoiding `any`s with Linting and TypeScript"
+  },
+  {
+    "date": "2024-09-30T00:00:00.000Z",
+    "description": "Explaining what linting with type information means, why it's so powerful, and some of the useful rules you can enable that use it.",
+    "readingTime": 8,
+    "slug": "typed-linting",
+    "title": "Typed Linting: The Most Powerful TypeScript Linting Ever"
+  }
+]

From 5474282cd4186d153e90c6261fa6db17ad986a6d Mon Sep 17 00:00:00 2001
From: Josh Goldberg <git@joshuakgoldberg.com>
Date: Fri, 4 Jul 2025 09:27:45 -0400
Subject: [PATCH 05/13] Unit tested the candidate detection

---
 .../src/getTsconfigRootDirFromStack.ts        |  2 +-
 packages/typescript-eslint/src/index.ts       |  5 +-
 .../typescript-eslint/tests/configs.test.ts   | 49 +++++++++++++++++++
 .../tests/getTsconfigRootDirFromStack.test.ts |  8 +--
 packages/typescript-estree/src/index.ts       |  5 +-
 5 files changed, 61 insertions(+), 8 deletions(-)

diff --git a/packages/typescript-eslint/src/getTsconfigRootDirFromStack.ts b/packages/typescript-eslint/src/getTsconfigRootDirFromStack.ts
index 7cc4e87a66fd..01378b1618f3 100644
--- a/packages/typescript-eslint/src/getTsconfigRootDirFromStack.ts
+++ b/packages/typescript-eslint/src/getTsconfigRootDirFromStack.ts
@@ -1,6 +1,6 @@
 import { fileURLToPath } from 'node:url';
 
-export function getTsconfigRootDirFromStack(stack: string): string | undefined {
+export function getTSConfigRootDirFromStack(stack: string): string | undefined {
   for (const line of stack.split('\n').map(line => line.trim())) {
     const candidate = /(\S+)eslint\.config\.(c|m)?(j|t)s/.exec(line)?.[1];
     if (!candidate) {
diff --git a/packages/typescript-eslint/src/index.ts b/packages/typescript-eslint/src/index.ts
index 91ac90534ccb..9892ede6065a 100644
--- a/packages/typescript-eslint/src/index.ts
+++ b/packages/typescript-eslint/src/index.ts
@@ -6,7 +6,7 @@ import rawPlugin from '@typescript-eslint/eslint-plugin/use-at-your-own-risk/raw
 import { addCandidateTSConfigRootDir } from '@typescript-eslint/typescript-estree';
 
 import { config } from './config-helper';
-import { getTsconfigRootDirFromStack } from './getTsconfigRootDirFromStack';
+import { getTSConfigRootDirFromStack } from './getTSConfigRootDirFromStack';
 
 export const parser: TSESLint.FlatConfig.Parser = rawPlugin.parser;
 
@@ -133,8 +133,9 @@ function createConfigsGetters<T extends object>(values: T): T {
       Object.entries(values).map(([key, value]: [string, unknown]) => [
         key,
         {
+          enumerable: true,
           get: () => {
-            const candidateRootDir = getTsconfigRootDirFromStack(
+            const candidateRootDir = getTSConfigRootDirFromStack(
               // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
               new Error().stack!,
             );
diff --git a/packages/typescript-eslint/tests/configs.test.ts b/packages/typescript-eslint/tests/configs.test.ts
index fea7a41196f4..cac7e4f46bd6 100644
--- a/packages/typescript-eslint/tests/configs.test.ts
+++ b/packages/typescript-eslint/tests/configs.test.ts
@@ -4,9 +4,25 @@ import type {
 } from '@typescript-eslint/utils/ts-eslint';
 
 import rules from '@typescript-eslint/eslint-plugin/use-at-your-own-risk/rules';
+import { clearCandidateTSConfigRootDirs } from '@typescript-eslint/typescript-estree';
 
 import tseslint from '../src/index.js';
 
+vi.mock('@typescript-eslint/typescript-estree', async () => ({
+  ...(await vi.importActual('@typescript-eslint/typescript-estree')),
+  get addCandidateTSConfigRootDir() {
+    return mockAddCandidateTSConfigRootDir;
+  },
+}));
+
+const mockGetTSConfigRootDirFromStack = vi.fn();
+
+vi.mock('../src/getTSConfigRootDirFromStack', () => ({
+  get getTSConfigRootDirFromStack() {
+    return mockGetTSConfigRootDirFromStack;
+  },
+}));
+
 const RULE_NAME_PREFIX = '@typescript-eslint/';
 const EXTENSION_RULES = Object.entries(rules)
   .filter(([, rule]) => rule.meta.docs.extendsBaseRule)
@@ -384,3 +400,36 @@ describe('stylistic-type-checked-only.ts', () => {
     },
   );
 });
+
+const mockAddCandidateTSConfigRootDir = vi.fn();
+
+describe('Candidate tsconfigRootDirs', () => {
+  beforeEach(() => {
+    clearCandidateTSConfigRootDirs();
+    mockAddCandidateTSConfigRootDir.mockClear();
+  });
+
+  describe.each(Object.keys(tseslint.configs))('%s', configKey => {
+    it('does not populate a candidate tsconfigRootDir when accessed and one cannot be inferred from the stack', () => {
+      mockGetTSConfigRootDirFromStack.mockReturnValue(undefined);
+
+      // eslint-disable-next-line @typescript-eslint/no-unused-expressions
+      tseslint.configs[configKey as keyof typeof tseslint.configs];
+
+      expect(mockAddCandidateTSConfigRootDir).not.toHaveBeenCalled();
+    });
+
+    it('populates a candidate tsconfigRootDir when accessed and one can be inferred from the stack', () => {
+      const tsconfigRootDir = 'a/b/c/';
+
+      mockGetTSConfigRootDirFromStack.mockReturnValue(tsconfigRootDir);
+
+      // eslint-disable-next-line @typescript-eslint/no-unused-expressions
+      tseslint.configs[configKey as keyof typeof tseslint.configs];
+
+      expect(mockAddCandidateTSConfigRootDir).toHaveBeenCalledWith(
+        tsconfigRootDir,
+      );
+    });
+  });
+});
diff --git a/packages/typescript-eslint/tests/getTsconfigRootDirFromStack.test.ts b/packages/typescript-eslint/tests/getTsconfigRootDirFromStack.test.ts
index 3f1ca139b301..1a8898faf059 100644
--- a/packages/typescript-eslint/tests/getTsconfigRootDirFromStack.test.ts
+++ b/packages/typescript-eslint/tests/getTsconfigRootDirFromStack.test.ts
@@ -1,10 +1,10 @@
 import path from 'node:path';
 
-import { getTsconfigRootDirFromStack } from '../src/getTsconfigRootDirFromStack';
+import { getTSConfigRootDirFromStack } from '../src/getTSConfigRootDirFromStack';
 
-describe(getTsconfigRootDirFromStack, () => {
+describe(getTSConfigRootDirFromStack, () => {
   it('returns undefined when no file path seems to be an ESLint config', () => {
-    const actual = getTsconfigRootDirFromStack(
+    const actual = getTSConfigRootDirFromStack(
       [
         `Error`,
         ' at file:///index.js',
@@ -24,7 +24,7 @@ describe(getTsconfigRootDirFromStack, () => {
           ? 'C:\\path\\to\\file\\'
           : '/path/to/file/';
 
-      const actual = getTsconfigRootDirFromStack(
+      const actual = getTSConfigRootDirFromStack(
         [
           `Error`,
           ` at ${path.join(expected, `eslint.config.${extension}`)}`,
diff --git a/packages/typescript-estree/src/index.ts b/packages/typescript-estree/src/index.ts
index a3beef50759c..654ea73982d2 100644
--- a/packages/typescript-estree/src/index.ts
+++ b/packages/typescript-estree/src/index.ts
@@ -16,7 +16,10 @@ export type {
   ParserServicesWithTypeInformation,
   TSESTreeOptions,
 } from './parser-options';
-export { addCandidateTSConfigRootDir } from './parseSettings/candidateTSConfigRootDirs';
+export {
+  addCandidateTSConfigRootDir,
+  clearCandidateTSConfigRootDirs,
+} from './parseSettings/candidateTSConfigRootDirs';
 export { simpleTraverse } from './simple-traverse';
 export * from './ts-estree';
 export { typescriptVersionIsAtLeast } from './version-check';

From 4d7aae939f0664b5e276b7b20fd55522d6ea23c6 Mon Sep 17 00:00:00 2001
From: Josh Goldberg <git@joshuakgoldberg.com>
Date: Fri, 4 Jul 2025 09:32:13 -0400
Subject: [PATCH 06/13] mv

---
 ...TsconfigRootDirFromStack.ts => getTSConfigRootDirFromStack.ts} | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
 rename packages/typescript-eslint/src/{getTsconfigRootDirFromStack.ts => getTSConfigRootDirFromStack.ts} (100%)

diff --git a/packages/typescript-eslint/src/getTsconfigRootDirFromStack.ts b/packages/typescript-eslint/src/getTSConfigRootDirFromStack.ts
similarity index 100%
rename from packages/typescript-eslint/src/getTsconfigRootDirFromStack.ts
rename to packages/typescript-eslint/src/getTSConfigRootDirFromStack.ts

From 3a94f405de52ce38bfbd128f9ef68a5f42828aa7 Mon Sep 17 00:00:00 2001
From: Josh Goldberg <git@joshuakgoldberg.com>
Date: Fri, 4 Jul 2025 09:38:23 -0400
Subject: [PATCH 07/13] rm packages/website/data/recent-blog-posts.json

---
 packages/website/data/recent-blog-posts.json | 23 --------------------
 1 file changed, 23 deletions(-)
 delete mode 100644 packages/website/data/recent-blog-posts.json

diff --git a/packages/website/data/recent-blog-posts.json b/packages/website/data/recent-blog-posts.json
deleted file mode 100644
index 9bc0ece682e5..000000000000
--- a/packages/website/data/recent-blog-posts.json
+++ /dev/null
@@ -1,23 +0,0 @@
-[
-  {
-    "date": "2025-05-29T00:00:00.000Z",
-    "description": "How typescript-eslint's new \"Project Service\" makes typed linting easier to configure, especially for large projects.",
-    "readingTime": 7,
-    "slug": "project-service",
-    "title": "Typed Linting with Project Service"
-  },
-  {
-    "date": "2025-01-21T00:00:00.000Z",
-    "description": "How typescript-eslint expands on TypeScript's type safety to catch explicit and implicit `any`s.",
-    "readingTime": 9,
-    "slug": "avoiding-anys",
-    "title": "Avoiding `any`s with Linting and TypeScript"
-  },
-  {
-    "date": "2024-09-30T00:00:00.000Z",
-    "description": "Explaining what linting with type information means, why it's so powerful, and some of the useful rules you can enable that use it.",
-    "readingTime": 8,
-    "slug": "typed-linting",
-    "title": "Typed Linting: The Most Powerful TypeScript Linting Ever"
-  }
-]

From 571870885c023e2740b916e186689972e6992a20 Mon Sep 17 00:00:00 2001
From: Josh Goldberg <git@joshuakgoldberg.com>
Date: Fri, 4 Jul 2025 10:03:43 -0400
Subject: [PATCH 08/13] chore: have website lint depend on its build

---
 packages/website/package.json | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/packages/website/package.json b/packages/website/package.json
index 117723cf3ace..528850f495fd 100644
--- a/packages/website/package.json
+++ b/packages/website/package.json
@@ -113,7 +113,10 @@
         }
       },
       "lint": {
-        "command": "eslint"
+        "command": "eslint",
+        "dependsOn": [
+          "build"
+        ]
       },
       "start": {
         "command": "docusaurus start",

From 9266c7d9ea20373d1a40878595024e4a61245d7c Mon Sep 17 00:00:00 2001
From: Josh Goldberg <git@joshuakgoldberg.com>
Date: Fri, 4 Jul 2025 10:15:14 -0400
Subject: [PATCH 09/13] Add file:/// testing back

---
 .../tests/getTsconfigRootDirFromStack.test.ts | 27 ++++++++++++++-----
 1 file changed, 21 insertions(+), 6 deletions(-)

diff --git a/packages/typescript-eslint/tests/getTsconfigRootDirFromStack.test.ts b/packages/typescript-eslint/tests/getTsconfigRootDirFromStack.test.ts
index 1a8898faf059..57a3b0b5f2a3 100644
--- a/packages/typescript-eslint/tests/getTsconfigRootDirFromStack.test.ts
+++ b/packages/typescript-eslint/tests/getTsconfigRootDirFromStack.test.ts
@@ -2,12 +2,14 @@ import path from 'node:path';
 
 import { getTSConfigRootDirFromStack } from '../src/getTSConfigRootDirFromStack';
 
+const isWindows = process.platform === 'win32';
+
 describe(getTSConfigRootDirFromStack, () => {
   it('returns undefined when no file path seems to be an ESLint config', () => {
     const actual = getTSConfigRootDirFromStack(
       [
         `Error`,
-        ' at file:///index.js',
+        ' at file:///other.config.js',
         ' at ModuleJob.run',
         'at async NodeHfs.walk(...)',
       ].join('\n'),
@@ -16,13 +18,26 @@ describe(getTSConfigRootDirFromStack, () => {
     expect(actual).toBeUndefined();
   });
 
+  it.runIf(!isWindows)(
+    'returns a Posix config file path when a file:// path to an ESLint config is in the stack',
+    () => {
+      const actual = getTSConfigRootDirFromStack(
+        [
+          `Error`,
+          ' at file:///path/to/file/eslint.config.js',
+          ' at ModuleJob.run',
+          'at async NodeHfs.walk(...)',
+        ].join('\n'),
+      );
+
+      expect(actual).toBe('/path/to/file/');
+    },
+  );
+
   it.each(['cjs', 'cts', 'js', 'mjs', 'mts', 'ts'])(
-    'returns the path to the config file when in a Posix system and its extension is %s',
+    'returns the path to the config file when its extension is %s',
     extension => {
-      const expected =
-        process.platform === 'win32'
-          ? 'C:\\path\\to\\file\\'
-          : '/path/to/file/';
+      const expected = isWindows ? 'C:\\path\\to\\file\\' : '/path/to/file/';
 
       const actual = getTSConfigRootDirFromStack(
         [

From 7c0a5fc8a27bcd7979b993908b1d91b2d3950053 Mon Sep 17 00:00:00 2001
From: Josh Goldberg <git@joshuakgoldberg.com>
Date: Wed, 9 Jul 2025 17:26:44 -0400
Subject: [PATCH 10/13] Add doc link

---
 .../src/parseSettings/candidateTSConfigRootDirs.ts               | 1 +
 1 file changed, 1 insertion(+)

diff --git a/packages/typescript-estree/src/parseSettings/candidateTSConfigRootDirs.ts b/packages/typescript-estree/src/parseSettings/candidateTSConfigRootDirs.ts
index 37b38dc1b435..13e19c8aac8a 100644
--- a/packages/typescript-estree/src/parseSettings/candidateTSConfigRootDirs.ts
+++ b/packages/typescript-estree/src/parseSettings/candidateTSConfigRootDirs.ts
@@ -24,6 +24,7 @@ export function getInferredTSConfigRootDir(): string {
           'No tsconfigRootDir was set, and multiple candidate TSConfigRootDirs are present:',
           ...entries.map(candidate => ` - ${candidate}`),
           "You'll need to explicitly set tsconfigRootDir in your parser options.",
+          'See: https://typescript-eslint.io/packages/parser/#tsconfigrootdir',
         ].join('\n'),
       );
   }

From 13879b7c87c7e472b55d5f6a013bb767585f8fb6 Mon Sep 17 00:00:00 2001
From: Josh Goldberg <git@joshuakgoldberg.com>
Date: Wed, 9 Jul 2025 17:27:28 -0400
Subject: [PATCH 11/13] dep

---
 packages/typescript-estree/package.json | 1 +
 yarn.lock                               | 1 +
 2 files changed, 2 insertions(+)

diff --git a/packages/typescript-estree/package.json b/packages/typescript-estree/package.json
index 96bbcff65e32..fd0b95462a45 100644
--- a/packages/typescript-estree/package.json
+++ b/packages/typescript-estree/package.json
@@ -55,6 +55,7 @@
     "@typescript-eslint/project-service": "8.35.1",
     "@typescript-eslint/tsconfig-utils": "8.35.1",
     "@typescript-eslint/types": "8.35.1",
+    "@typescript-eslint/typescript-estree": "8.35.1",
     "@typescript-eslint/visitor-keys": "8.35.1",
     "debug": "^4.3.4",
     "fast-glob": "^3.3.2",
diff --git a/yarn.lock b/yarn.lock
index 400a0f938286..d72e9977bb4a 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -6008,6 +6008,7 @@ __metadata:
     "@typescript-eslint/project-service": 8.35.1
     "@typescript-eslint/tsconfig-utils": 8.35.1
     "@typescript-eslint/types": 8.35.1
+    "@typescript-eslint/typescript-estree": 8.35.1
     "@typescript-eslint/visitor-keys": 8.35.1
     "@vitest/coverage-v8": ^3.1.3
     debug: ^4.3.4

From 37d822b1d15785fe9ff151d792f1d3d48e67608a Mon Sep 17 00:00:00 2001
From: Josh Goldberg <git@joshuakgoldberg.com>
Date: Wed, 9 Jul 2025 18:27:58 -0400
Subject: [PATCH 12/13] Heh, wrong paackage

---
 packages/typescript-eslint/package.json | 1 +
 packages/typescript-estree/package.json | 1 -
 yarn.lock                               | 2 +-
 3 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/typescript-eslint/package.json b/packages/typescript-eslint/package.json
index f68c8c9991b7..6c0144e06b20 100644
--- a/packages/typescript-eslint/package.json
+++ b/packages/typescript-eslint/package.json
@@ -52,6 +52,7 @@
   "dependencies": {
     "@typescript-eslint/eslint-plugin": "8.36.0",
     "@typescript-eslint/parser": "8.36.0",
+    "@typescript-eslint/typescript-estree": "8.36.0",
     "@typescript-eslint/utils": "8.36.0"
   },
   "peerDependencies": {
diff --git a/packages/typescript-estree/package.json b/packages/typescript-estree/package.json
index d794c4139a02..b6a2ff8b2468 100644
--- a/packages/typescript-estree/package.json
+++ b/packages/typescript-estree/package.json
@@ -55,7 +55,6 @@
     "@typescript-eslint/project-service": "8.36.0",
     "@typescript-eslint/tsconfig-utils": "8.36.0",
     "@typescript-eslint/types": "8.36.0",
-    "@typescript-eslint/typescript-estree": "8.36.0",
     "@typescript-eslint/visitor-keys": "8.36.0",
     "debug": "^4.3.4",
     "fast-glob": "^3.3.2",
diff --git a/yarn.lock b/yarn.lock
index 160d31b9b942..08bde6338a88 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -6214,7 +6214,6 @@ __metadata:
     "@typescript-eslint/project-service": 8.36.0
     "@typescript-eslint/tsconfig-utils": 8.36.0
     "@typescript-eslint/types": 8.36.0
-    "@typescript-eslint/typescript-estree": 8.36.0
     "@typescript-eslint/visitor-keys": 8.36.0
     "@vitest/coverage-v8": ^3.1.3
     debug: ^4.3.4
@@ -19803,6 +19802,7 @@ __metadata:
   dependencies:
     "@typescript-eslint/eslint-plugin": 8.36.0
     "@typescript-eslint/parser": 8.36.0
+    "@typescript-eslint/typescript-estree": 8.36.0
     "@typescript-eslint/utils": 8.36.0
     "@vitest/coverage-v8": ^3.1.3
     eslint: "*"

From 718b8810c48e4c7f8e39a288c437e63c6799f11b Mon Sep 17 00:00:00 2001
From: Josh Goldberg <git@joshuakgoldberg.com>
Date: Wed, 9 Jul 2025 18:36:08 -0400
Subject: [PATCH 13/13] yarn test -u

---
 .../tests/lib/candidateTSConfigRootDirs.test.ts       | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/packages/typescript-estree/tests/lib/candidateTSConfigRootDirs.test.ts b/packages/typescript-estree/tests/lib/candidateTSConfigRootDirs.test.ts
index 9f59d6f507f9..7536d56a205d 100644
--- a/packages/typescript-estree/tests/lib/candidateTSConfigRootDirs.test.ts
+++ b/packages/typescript-estree/tests/lib/candidateTSConfigRootDirs.test.ts
@@ -30,10 +30,11 @@ describe(getInferredTSConfigRootDir, () => {
 
     expect(() => getInferredTSConfigRootDir())
       .toThrowErrorMatchingInlineSnapshot(`
-      [Error: No tsconfigRootDir was set, and multiple candidate TSConfigRootDirs are present:
-       - a
-       - b
-      You'll need to explicitly set tsconfigRootDir in your parser options.]
-    `);
+        [Error: No tsconfigRootDir was set, and multiple candidate TSConfigRootDirs are present:
+         - a
+         - b
+        You'll need to explicitly set tsconfigRootDir in your parser options.
+        See: https://typescript-eslint.io/packages/parser/#tsconfigrootdir]
+      `);
   });
 });

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