typescript-eslint · JoshuaKGoldberg · Nov 10, 2025 · Jun 23, 2025 · Oct 2, 2025 · Oct 2, 2025
diff --git a/packages/eslint-plugin-internal/tests/rules/no-poorly-typed-ts-props.test.ts b/packages/eslint-plugin-internal/tests/rules/no-poorly-typed-ts-props.test.ts
@@ -8,6 +8,7 @@ const ruleTester = new RuleTester({
   languageOptions: {
     parserOptions: {
       project: './tsconfig.json',
+      projectService: false,
       tsconfigRootDir: getFixturesRootDir(),
     },
   },

diff --git a/packages/eslint-plugin-internal/tests/rules/plugin-test-formatting.test.ts b/packages/eslint-plugin-internal/tests/rules/plugin-test-formatting.test.ts
@@ -7,6 +7,7 @@ const ruleTester = new RuleTester({
   languageOptions: {
     parserOptions: {
       project: './tsconfig.json',
+      projectService: false,
       tsconfigRootDir: getFixturesRootDir(),
     },
   },

diff --git a/packages/eslint-plugin/tests/RuleTester.ts b/packages/eslint-plugin/tests/RuleTester.ts
@@ -1,5 +1,37 @@
+import type { ParserOptions } from '@typescript-eslint/utils/ts-eslint';
+
+import { RuleTester } from '@typescript-eslint/rule-tester';
 import * as path from 'node:path';
 
+export function createRuleTesterWithTypes(
+  providedParserOptions: ParserOptions | undefined = {},
+): RuleTester {
+  const parserOptions = {
+    ...providedParserOptions,
+    tsconfigRootDir:
+      providedParserOptions.tsconfigRootDir ?? getFixturesRootDir(),
+  };
+
+  // If the test has requested a specific project, disable projectService
+  // (regardless of whether it's being switched to by TYPESCRIPT_ESLINT_PROJECT_SERVICE)
+  if (parserOptions.project) {
+    parserOptions.projectService = false;
+  }
+  // Otherwise, use the project service for types if requested in the env
+  else if (process.env.TYPESCRIPT_ESLINT_PROJECT_SERVICE) {
+    parserOptions.projectService = true;
+  }
+  // Finally, default to project: true as the standard (legacy) behavior
+  // See: https://github.com/typescript-eslint/typescript-eslint/issues/11676
+  else {
+    parserOptions.project = true;
+  }
+
+  return new RuleTester({
+    languageOptions: { parserOptions },
+  });
+}
+
 export function getFixturesRootDir(): string {
   return path.join(__dirname, 'fixtures');
 }
diff --git a/packages/eslint-plugin/tests/docs.test.mts b/packages/eslint-plugin/tests/docs.test.mts
@@ -428,6 +428,7 @@ describe('Validating rule docs', () => {
           parserOptions: {
             disallowAutomaticSingleRunInference: true,
             project: './tsconfig.json',
+            projectService: false,
             tsconfigRootDir: FIXTURES_DIR,
           },
           rules: Object.fromEntries(ruleEntries),

diff --git a/packages/eslint-plugin/tests/rules/await-thenable.test.ts b/packages/eslint-plugin/tests/rules/await-thenable.test.ts
@@ -1,18 +1,9 @@
-import { noFormat, RuleTester } from '@typescript-eslint/rule-tester';
+import { noFormat } from '@typescript-eslint/rule-tester';
 
 import rule from '../../src/rules/await-thenable';
-import { getFixturesRootDir } from '../RuleTester';
+import { createRuleTesterWithTypes } from '../RuleTester';
 
-const rootDir = getFixturesRootDir();
-
-const ruleTester = new RuleTester({
-  languageOptions: {
-    parserOptions: {
-      project: './tsconfig.json',
-      tsconfigRootDir: rootDir,
-    },
-  },
-});
+const ruleTester = createRuleTesterWithTypes();
 
 ruleTester.run('await-thenable', rule, {
   valid: [

diff --git a/packages/eslint-plugin/tests/rules/consistent-return.test.ts b/packages/eslint-plugin/tests/rules/consistent-return.test.ts
@@ -1,17 +1,7 @@
-import { RuleTester } from '@typescript-eslint/rule-tester';
-
 import rule from '../../src/rules/consistent-return';
-import { getFixturesRootDir } from '../RuleTester';
+import { createRuleTesterWithTypes } from '../RuleTester';
 
-const rootDir = getFixturesRootDir();
-const ruleTester = new RuleTester({
-  languageOptions: {
-    parserOptions: {
-      project: './tsconfig.json',
-      tsconfigRootDir: rootDir,
-    },
-  },
-});
+const ruleTester = createRuleTesterWithTypes();
 
 ruleTester.run('consistent-return', rule, {
   valid: [

diff --git a/packages/eslint-plugin/tests/rules/consistent-type-exports.test.ts b/packages/eslint-plugin/tests/rules/consistent-type-exports.test.ts
@@ -1,18 +1,11 @@
 /* eslint-disable @typescript-eslint/internal/plugin-test-formatting -- Prettier doesn't yet support TS 5.6 string literal module identifiers */
-import { noFormat, RuleTester } from '@typescript-eslint/rule-tester';
+import { noFormat } from '@typescript-eslint/rule-tester';
 
 import rule from '../../src/rules/consistent-type-exports';
-import { getFixturesRootDir } from '../RuleTester';
+import { createRuleTesterWithTypes } from '../RuleTester';
 
-const rootDir = getFixturesRootDir();
-
-const ruleTester = new RuleTester({
-  languageOptions: {
-    parserOptions: {
-      project: './tsconfig.json',
-      tsconfigRootDir: rootDir,
-    },
-  },
+const ruleTester = createRuleTesterWithTypes({
+  project: './tsconfig.json',
 });
 
 ruleTester.run('consistent-type-exports', rule, {

diff --git a/packages/eslint-plugin/tests/rules/dot-notation.test.ts b/packages/eslint-plugin/tests/rules/dot-notation.test.ts
@@ -1,18 +1,10 @@
-import { noFormat, RuleTester } from '@typescript-eslint/rule-tester';
+import { noFormat } from '@typescript-eslint/rule-tester';
 
 import rule from '../../src/rules/dot-notation';
-import { getFixturesRootDir } from '../RuleTester';
+import { createRuleTesterWithTypes, getFixturesRootDir } from '../RuleTester';
 
-const rootPath = getFixturesRootDir();
-
-const ruleTester = new RuleTester({
-  languageOptions: {
-    parserOptions: {
-      project: './tsconfig.json',
-      tsconfigRootDir: rootPath,
-    },
-  },
-});
+const rootDir = getFixturesRootDir();
+const ruleTester = createRuleTesterWithTypes();
 
 /**
  * Quote a string in "double quotes" because it’s painful
@@ -163,7 +155,7 @@ foo['key_baz'];
         parserOptions: {
           project: './tsconfig.noPropertyAccessFromIndexSignature.json',
           projectService: false,
-          tsconfigRootDir: rootPath,
+          tsconfigRootDir: rootDir,
         },
       },
     },
@@ -181,7 +173,7 @@ foo['bar'];
         parserOptions: {
           project: './tsconfig.noPropertyAccessFromIndexSignature.json',
           projectService: false,
-          tsconfigRootDir: rootPath,
+          tsconfigRootDir: rootDir,
         },
       },
     },
@@ -202,7 +194,7 @@ function f<T extends Foo>(x: T) {
         parserOptions: {
           project: './tsconfig.noPropertyAccessFromIndexSignature.json',
           projectService: false,
-          tsconfigRootDir: rootPath,
+          tsconfigRootDir: rootDir,
         },
       },
     },

diff --git a/packages/eslint-plugin/tests/rules/naming-convention/naming-convention.test.ts b/packages/eslint-plugin/tests/rules/naming-convention/naming-convention.test.ts
@@ -11,6 +11,7 @@ const ruleTester = new RuleTester();
 const rootDir = getFixturesRootDir();
 const parserOptions = {
   project: './tsconfig.json',
+  projectService: false,
   tsconfigRootDir: rootDir,
 };
 

diff --git a/packages/eslint-plugin/tests/rules/no-array-delete.test.ts b/packages/eslint-plugin/tests/rules/no-array-delete.test.ts
@@ -1,18 +1,9 @@
-import { noFormat, RuleTester } from '@typescript-eslint/rule-tester';
+import { noFormat } from '@typescript-eslint/rule-tester';
 
 import rule from '../../src/rules/no-array-delete';
-import { getFixturesRootDir } from '../RuleTester';
+import { createRuleTesterWithTypes } from '../RuleTester';
 
-const rootPath = getFixturesRootDir();
-
-const ruleTester = new RuleTester({
-  languageOptions: {
-    parserOptions: {
-      project: './tsconfig.json',
-      tsconfigRootDir: rootPath,
-    },
-  },
-});
+const ruleTester = createRuleTesterWithTypes();
 
 ruleTester.run('no-array-delete', rule, {
   valid: [

diff --git a/packages/eslint-plugin/tests/rules/no-base-to-string.test.ts b/packages/eslint-plugin/tests/rules/no-base-to-string.test.ts
@@ -1,17 +1,8 @@
-import { RuleTester } from '@typescript-eslint/rule-tester';
-
 import rule from '../../src/rules/no-base-to-string';
-import { getFixturesRootDir } from '../RuleTester';
+import { createRuleTesterWithTypes, getFixturesRootDir } from '../RuleTester';
 
 const rootDir = getFixturesRootDir();
-const ruleTester = new RuleTester({
-  languageOptions: {
-    parserOptions: {
-      project: './tsconfig.json',
-      tsconfigRootDir: rootDir,
-    },
-  },
-});
+const ruleTester = createRuleTesterWithTypes();
 
 /**
  * ref: https://github.com/typescript-eslint/typescript-eslint/issues/11043
@@ -1382,6 +1373,7 @@ declare const foo: Bar & Foo;
       languageOptions: {
         parserOptions: {
           project: './tsconfig.noUncheckedIndexedAccess.json',
+          projectService: false,
           tsconfigRootDir: rootDir,
         },
       },
@@ -1632,6 +1624,7 @@ declare const foo: Bar & Foo;
       languageOptions: {
         parserOptions: {
           project: './tsconfig.noUncheckedIndexedAccess.json',
+          projectService: false,
           tsconfigRootDir: rootDir,
         },
       },
@@ -1882,6 +1875,7 @@ declare const foo: Bar & Foo;
       languageOptions: {
         parserOptions: {
           project: './tsconfig.noUncheckedIndexedAccess.json',
+          projectService: false,
           tsconfigRootDir: rootDir,
         },
       },
@@ -2132,6 +2126,7 @@ declare const foo: Bar & Foo;
       languageOptions: {
         parserOptions: {
           project: './tsconfig.noUncheckedIndexedAccess.json',
+          projectService: false,
           tsconfigRootDir: rootDir,
         },
       },

diff --git a/packages/eslint-plugin/tests/rules/no-confusing-void-expression.test.ts b/packages/eslint-plugin/tests/rules/no-confusing-void-expression.test.ts
@@ -1,17 +1,9 @@
-import { noFormat, RuleTester } from '@typescript-eslint/rule-tester';
+import { noFormat } from '@typescript-eslint/rule-tester';
 
 import rule from '../../src/rules/no-confusing-void-expression';
-import { getFixturesRootDir } from '../RuleTester';
+import { createRuleTesterWithTypes } from '../RuleTester';
 
-const rootPath = getFixturesRootDir();
-const ruleTester = new RuleTester({
-  languageOptions: {
-    parserOptions: {
-      project: './tsconfig.json',
-      tsconfigRootDir: rootPath,
-    },
-  },
-});
+const ruleTester = createRuleTesterWithTypes();
 
 ruleTester.run('no-confusing-void-expression', rule, {
   valid: [

diff --git a/packages/eslint-plugin/tests/rules/no-deprecated.test.ts b/packages/eslint-plugin/tests/rules/no-deprecated.test.ts
@@ -1,19 +1,12 @@
-import { RuleTester } from '@typescript-eslint/rule-tester';
-
 import rule from '../../src/rules/no-deprecated';
-import { getFixturesRootDir } from '../RuleTester';
+import { getFixturesRootDir, createRuleTesterWithTypes } from '../RuleTester';
 
 const rootDir = getFixturesRootDir();
-const ruleTester = new RuleTester({
-  languageOptions: {
-    parserOptions: {
-      ecmaFeatures: {
-        jsx: true,
-      },
-      project: './tsconfig.json',
-      tsconfigRootDir: rootDir,
-    },
+const ruleTester = createRuleTesterWithTypes({
+  ecmaFeatures: {
+    jsx: true,
   },
+  project: './tsconfig.json',
 });
 
 ruleTester.run('no-deprecated', rule, {

diff --git a/packages/eslint-plugin/tests/rules/no-duplicate-type-constituents.test.ts b/packages/eslint-plugin/tests/rules/no-duplicate-type-constituents.test.ts
@@ -1,18 +1,7 @@
-import { RuleTester } from '@typescript-eslint/rule-tester';
-
 import rule from '../../src/rules/no-duplicate-type-constituents';
-import { getFixturesRootDir } from '../RuleTester';
-
-const rootPath = getFixturesRootDir();
+import { createRuleTesterWithTypes } from '../RuleTester';
 
-const ruleTester = new RuleTester({
-  languageOptions: {
-    parserOptions: {
-      project: './tsconfig.json',
-      tsconfigRootDir: rootPath,
-    },
-  },
-});
+const ruleTester = createRuleTesterWithTypes();
 
 ruleTester.run('no-duplicate-type-constituents', rule, {
   valid: [

diff --git a/packages/eslint-plugin/tests/rules/no-dynamic-delete.test.ts b/packages/eslint-plugin/tests/rules/no-dynamic-delete.test.ts
@@ -1,18 +1,7 @@
-import { RuleTester } from '@typescript-eslint/rule-tester';
-
 import rule from '../../src/rules/no-dynamic-delete';
-import { getFixturesRootDir } from '../RuleTester';
-
-const rootPath = getFixturesRootDir();
+import { createRuleTesterWithTypes } from '../RuleTester';
 
-const ruleTester = new RuleTester({
-  languageOptions: {
-    parserOptions: {
-      project: './tsconfig.json',
-      tsconfigRootDir: rootPath,
-    },
-  },
-});
+const ruleTester = createRuleTesterWithTypes();
 
 ruleTester.run('no-dynamic-delete', rule, {
   valid: [

diff --git a/packages/eslint-plugin/tests/rules/no-floating-promises.test.ts b/packages/eslint-plugin/tests/rules/no-floating-promises.test.ts
@@ -1,19 +1,10 @@
-import { RuleTester } from '@typescript-eslint/rule-tester';
 import * as path from 'node:path';
 
 import rule from '../../src/rules/no-floating-promises';
-import { getFixturesRootDir } from '../RuleTester';
+import { createRuleTesterWithTypes, getFixturesRootDir } from '../RuleTester';
 
 const rootDir = getFixturesRootDir();
-
-const ruleTester = new RuleTester({
-  languageOptions: {
-    parserOptions: {
-      project: './tsconfig.json',
-      tsconfigRootDir: rootDir,
-    },
-  },
-});
+const ruleTester = createRuleTesterWithTypes();
 
 ruleTester.run('no-floating-promises', rule, {
   valid: [

diff --git a/packages/eslint-plugin/tests/rules/no-for-in-array.test.ts b/packages/eslint-plugin/tests/rules/no-for-in-array.test.ts
@@ -1,17 +1,10 @@
-import { noFormat, RuleTester } from '@typescript-eslint/rule-tester';
+import { noFormat } from '@typescript-eslint/rule-tester';
 
 import rule from '../../src/rules/no-for-in-array';
-import { getFixturesRootDir } from '../RuleTester';
+import { createRuleTesterWithTypes, getFixturesRootDir } from '../RuleTester';
 
 const rootDir = getFixturesRootDir();
-const ruleTester = new RuleTester({
-  languageOptions: {
-    parserOptions: {
-      project: './tsconfig.json',
-      tsconfigRootDir: rootDir,
-    },
-  },
-});
+const ruleTester = createRuleTesterWithTypes();
 
 ruleTester.run('no-for-in-array', rule, {
   valid: [