typescript-eslint · bradzacher · Aug 16, 2025 · Aug 13, 2025 · Aug 13, 2025 · bradzacher
diff --git a/packages/typescript-eslint/package.json b/packages/typescript-eslint/package.json
@@ -78,6 +78,18 @@
     "targets": {
       "lint": {
         "command": "eslint"
+      },
+      "typecheck": {
+        "outputs": [
+          "{workspaceRoot}/dist",
+          "{projectRoot}/dist"
+        ]
+      },
+      "test": {
+        "dependsOn": [
+          "^build",
+          "typecheck"
+        ]
       }
     }
   }

diff --git a/packages/typescript-eslint/src/compatibility-types.ts b/packages/typescript-eslint/src/compatibility-types.ts
@@ -0,0 +1,25 @@
+/*
+ * This file contains types that are intentionally wide/inaccurate, that exist
+ * for the purpose of satisfying both `defineConfig()` and `tseslint.config()`.
+ * See https://github.com/typescript-eslint/typescript-eslint/issues/10899
+ */
+
+export interface CompatibleParser {
+  parseForESLint(text: string): {
+    ast: unknown;
+    scopeManager: unknown;
+  };
+}
+
+export interface CompatibleConfig {
+  name?: string;
+  rules?: object;
+}
+
+export type CompatibleConfigArray = CompatibleConfig[];
+
+export interface CompatiblePlugin {
+  meta: {
+    name: string;
+  };
+}
diff --git a/packages/typescript-eslint/src/index.ts b/packages/typescript-eslint/src/index.ts
@@ -1,14 +1,23 @@
 // see the comment in config-helper.ts for why this doesn't use /ts-eslint
 import type { TSESLint } from '@typescript-eslint/utils';
+import type { FlatConfig } from '@typescript-eslint/utils/ts-eslint';
 
 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 type {
+  CompatibleConfig,
+  CompatibleConfigArray,
+  CompatibleParser,
+  CompatiblePlugin,
+} from './compatibility-types';
+
 import { config } from './config-helper';
 import { getTSConfigRootDirFromStack } from './getTSConfigRootDirFromStack';
 
-export const parser: TSESLint.FlatConfig.Parser = rawPlugin.parser;
+export const parser: CompatibleParser =
+  rawPlugin.parser as CompatibleParser satisfies FlatConfig.Parser;
 
 /*
 we could build a plugin object here without the `configs` key - but if we do
@@ -33,96 +42,109 @@ use our new package); however legacy configs consumed via `@eslint/eslintrc`
 would never be able to satisfy this constraint and thus users would be blocked
 from using them.
 */
-export const plugin: TSESLint.FlatConfig.Plugin = pluginBase as Omit<
-  typeof pluginBase,
-  'configs'
->;
+export const plugin: CompatiblePlugin =
+  pluginBase satisfies FlatConfig.Plugins['string'];
 
 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}
    */
-  all: rawPlugin.flatConfigs['flat/all'],
+  all: rawPlugin.flatConfigs['flat/all'] as CompatibleConfigArray,
 
   /**
    * A minimal ruleset that sets only the required parser and plugin options needed to run typescript-eslint.
    * We don't recommend using this directly; instead, extend from an earlier recommended rule.
    * @see {@link https://typescript-eslint.io/users/configs#base}
    */
-  base: rawPlugin.flatConfigs['flat/base'],
+  base: rawPlugin.flatConfigs['flat/base'] as CompatibleConfig,
 
   /**
    * A utility ruleset that will disable type-aware linting and all type-aware rules available in our project.
    * @see {@link https://typescript-eslint.io/users/configs#disable-type-checked}
    */
-  disableTypeChecked: rawPlugin.flatConfigs['flat/disable-type-checked'],
+  disableTypeChecked: rawPlugin.flatConfigs[
+    'flat/disable-type-checked'
+  ] as CompatibleConfig,
 
   /**
    * This is a compatibility ruleset that:
    * - disables rules from eslint:recommended which are already handled by TypeScript.
    * - enables rules that make sense due to TS's typechecking / transpilation.
    * @see {@link https://typescript-eslint.io/users/configs/#eslint-recommended}
    */
-  eslintRecommended: rawPlugin.flatConfigs['flat/eslint-recommended'],
+  eslintRecommended: rawPlugin.flatConfigs[
+    'flat/eslint-recommended'
+  ] as CompatibleConfig,
 
   /**
    * Recommended rules for code correctness that you can drop in without additional configuration.
    * @see {@link https://typescript-eslint.io/users/configs#recommended}
    */
-  recommended: rawPlugin.flatConfigs['flat/recommended'],
+  recommended: rawPlugin.flatConfigs[
+    'flat/recommended'
+  ] as CompatibleConfigArray,
 
   /**
    * Contains all of `recommended` along with additional recommended rules that require type information.
    * @see {@link https://typescript-eslint.io/users/configs#recommended-type-checked}
    */
-  recommendedTypeChecked:
-    rawPlugin.flatConfigs['flat/recommended-type-checked'],
+  recommendedTypeChecked: rawPlugin.flatConfigs[
+    'flat/recommended-type-checked'
+  ] as CompatibleConfigArray,
 
   /**
    * A version of `recommended` that only contains type-checked rules and disables of any corresponding core ESLint rules.
    * @see {@link https://typescript-eslint.io/users/configs#recommended-type-checked-only}
    */
-  recommendedTypeCheckedOnly:
-    rawPlugin.flatConfigs['flat/recommended-type-checked-only'],
+  recommendedTypeCheckedOnly: rawPlugin.flatConfigs[
+    'flat/recommended-type-checked-only'
+  ] as CompatibleConfigArray,
 
   /**
    * Contains all of `recommended`, as well as additional strict rules that can also catch bugs.
    * @see {@link https://typescript-eslint.io/users/configs#strict}
    */
-  strict: rawPlugin.flatConfigs['flat/strict'],
+  strict: rawPlugin.flatConfigs['flat/strict'] as CompatibleConfigArray,
 
   /**
    * Contains all of `recommended`, `recommended-type-checked`, and `strict`, along with additional strict rules that require type information.
    * @see {@link https://typescript-eslint.io/users/configs#strict-type-checked}
    */
-  strictTypeChecked: rawPlugin.flatConfigs['flat/strict-type-checked'],
+  strictTypeChecked: rawPlugin.flatConfigs[
+    'flat/strict-type-checked'
+  ] as CompatibleConfigArray,
 
   /**
    * A version of `strict` that only contains type-checked rules and disables of any corresponding core ESLint rules.
    * @see {@link https://typescript-eslint.io/users/configs#strict-type-checked-only}
    */
-  strictTypeCheckedOnly: rawPlugin.flatConfigs['flat/strict-type-checked-only'],
+  strictTypeCheckedOnly: rawPlugin.flatConfigs[
+    'flat/strict-type-checked-only'
+  ] as CompatibleConfigArray,
 
   /**
    * Rules considered to be best practice for modern TypeScript codebases, but that do not impact program logic.
    * @see {@link https://typescript-eslint.io/users/configs#stylistic}
    */
-  stylistic: rawPlugin.flatConfigs['flat/stylistic'],
+  stylistic: rawPlugin.flatConfigs['flat/stylistic'] as CompatibleConfigArray,
 
   /**
    * Contains all of `stylistic`, along with additional stylistic rules that require type information.
    * @see {@link https://typescript-eslint.io/users/configs#stylistic-type-checked}
    */
-  stylisticTypeChecked: rawPlugin.flatConfigs['flat/stylistic-type-checked'],
+  stylisticTypeChecked: rawPlugin.flatConfigs[
+    'flat/stylistic-type-checked'
+  ] as CompatibleConfigArray,
 
   /**
    * A version of `stylistic` that only contains type-checked rules and disables of any corresponding core ESLint rules.
    * @see {@link https://typescript-eslint.io/users/configs#stylistic-type-checked-only}
    */
-  stylisticTypeCheckedOnly:
-    rawPlugin.flatConfigs['flat/stylistic-type-checked-only'],
-});
+  stylisticTypeCheckedOnly: rawPlugin.flatConfigs[
+    'flat/stylistic-type-checked-only'
+  ] as CompatibleConfigArray,
+}) satisfies Record<string, FlatConfig.Config | FlatConfig.ConfigArray>;
 
 function createConfigsGetters<T extends object>(values: T): T {
   const configs = {};

diff --git a/packages/typescript-eslint/tests/type-compatibility.test-d.ts b/packages/typescript-eslint/tests/type-compatibility.test-d.ts
@@ -0,0 +1,49 @@
+import { defineConfig } from 'eslint/config';
+
+import tseslint from '../src/index';
+
+describe('test for compatibility with config helpers', () => {
+  test('exported plugin is compatible with tseslint.config()', () => {
+    tseslint.config({
+      plugins: {
+        '@typescript-eslint': tseslint.plugin,
+      },
+    });
+  });
+
+  test('exported plugin is compatible with defineConfig()', () => {
+    defineConfig({
+      plugins: {
+        '@typescript-eslint': tseslint.plugin,
+      },
+    });
+  });
+
+  test('exported parser is compatible with tseslint.config()', () => {
+    tseslint.config({
+      languageOptions: {
+        parser: tseslint.parser,
+      },
+    });
+  });
+
+  test('exported parser is compatible with defineConfig()', () => {
+    defineConfig({
+      languageOptions: {
+        parser: tseslint.parser,
+      },
+    });
+  });
+
+  test('exported configs are compatible with tseslint.config()', () => {
+    tseslint.config(tseslint.configs.recommendedTypeChecked);
+    tseslint.config(tseslint.configs.strict);
+    tseslint.config(tseslint.configs.eslintRecommended);
+  });
+
+  test('exported configs are compatible with defineConfig()', () => {
+    defineConfig(tseslint.configs.recommendedTypeChecked);
+    defineConfig(tseslint.configs.strict);
+    defineConfig(tseslint.configs.eslintRecommended);
+  });
+});
diff --git a/packages/typescript-eslint/vitest.config.mts b/packages/typescript-eslint/vitest.config.mts
@@ -14,6 +14,10 @@ const vitestConfig = mergeConfig(
       dir: path.join(import.meta.dirname, 'tests'),
       name: packageJson.name,
       root: import.meta.dirname,
+      typecheck: {
+        enabled: true,
+        tsconfig: path.join(import.meta.dirname, 'tsconfig.spec.json'),
+      },
     },
   }),
 );