[heft-lint-plugin] Lint files selected by ESLint flat config

apps/playwright-browser-tunnel/eslint.config.js

@@ -14,5 +14,24 @@ module.exports = [
         tsconfigRootDir: __dirname
       }
     }
+  },
+  {
+    // The Playwright config and test files are not part of the project's TypeScript program (they are excluded
+    // from tsconfig.json), so disable type-aware parsing and the profile's type-aware rules and lint them with
+    // only the non-type-aware rules.
+    // TODO: Replace this with the `@rushstack/eslint-config` `without-type-information` helper once that package
+    // is published and consumed by the node rigs.
+    files: ['playwright.config.ts', 'tests/**/*.ts'],
+    languageOptions: {
+      parserOptions: {
+        project: false,
+        projectService: false
+      }
+    },
+    rules: {
+      '@typescript-eslint/naming-convention': 'off',
+      '@typescript-eslint/no-floating-promises': 'off',
+      '@typescript-eslint/no-for-in-array': 'off'
+    }
   }
 ];

apps/playwright-browser-tunnel/playwright.config.ts

@@ -1,3 +1,6 @@
+// Copyright (c) Microsoft Corporation. All rights reserved. Licensed under the MIT license.
+// See LICENSE in the project root for license information.
+
 import { defineConfig, devices } from '@playwright/test';
 
 export default defineConfig({

apps/playwright-browser-tunnel/tests/testFixture.ts

@@ -2,14 +2,18 @@
 // See LICENSE in the project root for license information.
 
 import { test as base } from '@playwright/test';
-import { tunneledBrowser } from '../src/tunneledBrowserConnection';
 
-export const test = base.extend({
+import {
+  createTunneledBrowserAsync,
+  type IDisposableTunneledBrowser
+} from '../src/tunneledBrowserConnection';
+
+export const test: typeof base = base.extend({
   browser: [
     async ({ browserName, launchOptions, channel, headless }, use) => {
-      console.log(`Starting tunnel server for browser: ${browserName}, channel: ${channel}`);
+      console.info(`Starting tunnel server for browser: ${browserName}, channel: ${channel}`);
 
-      await using tunnel = await tunneledBrowser(browserName, {
+      await using tunnel: IDisposableTunneledBrowser = await createTunneledBrowserAsync(browserName, {
         channel,
         headless,
         ...launchOptions

build-tests/eslint-9-test/.eslint-bulk-suppressions.json

@@ -4,6 +4,11 @@
       "file": "src/index.ts",
       "scopeId": ".",
       "rule": "@typescript-eslint/naming-convention"
+    },
+    {
+      "file": "src/non-program.custom",
+      "scopeId": ".",
+      "rule": "no-undef"
     }
   ]
 }

build-tests/eslint-9-test/eslint.config.js

@@ -7,6 +7,9 @@ const nodeTrustedToolProfile = require('local-node-rig/profiles/default/includes
 const friendlyLocalsMixin = require('local-node-rig/profiles/default/includes/eslint/flat/mixins/friendly-locals');
 
 module.exports = [
+  {
+    ignores: ['coverage/**']
+  },
   ...nodeTrustedToolProfile,
   ...friendlyLocalsMixin,
   {
@@ -25,5 +28,11 @@ module.exports = [
         tsconfigRootDir: __dirname
       }
     }
+  },
+  {
+    files: ['**/*.custom'],
+    rules: {
+      'no-undef': 'warn'
+    }
   }
 ];

build-tests/eslint-9-test/src/__snapshots__/sarif.test.ts.snap

@@ -16,6 +16,11 @@ Object {
             "uri": "src/sarif.test.ts",
           },
         },
+        Object {
+          "location": Object {
+            "uri": "src/non-program.custom",
+          },
+        },
       ],
       "results": Array [
         Object {
@@ -78,6 +83,36 @@ Object {
             },
           ],
         },
+        Object {
+          "level": "warning",
+          "locations": Array [
+            Object {
+              "physicalLocation": Object {
+                "artifactLocation": Object {
+                  "index": 2,
+                  "uri": "src/non-program.custom",
+                },
+                "region": Object {
+                  "endColumn": 14,
+                  "endLine": 1,
+                  "startColumn": 1,
+                  "startLine": 1,
+                },
+              },
+            },
+          ],
+          "message": Object {
+            "text": "'missingGlobal' is not defined.",
+          },
+          "ruleId": "no-undef",
+          "ruleIndex": 2,
+          "suppressions": Array [
+            Object {
+              "justification": "",
+              "kind": "external",
+            },
+          ],
+        },
       ],
       "tool": Object {
         "driver": Object {
@@ -100,6 +135,14 @@ Object {
                 "text": "Enforce naming conventions for everything across a codebase",
               },
             },
+            Object {
+              "helpUri": "https://eslint.org/docs/latest/rules/no-undef",
+              "id": "no-undef",
+              "properties": Object {},
+              "shortDescription": Object {
+                "text": "Disallow the use of undeclared variables unless mentioned in \`/*global */\` comments",
+              },
+            },
           ],
           "version": "9.37.0",
         },

build-tests/eslint-9-test/src/non-program.custom

@@ -0,0 +1 @@
+missingGlobal;

common/changes/@rushstack/eslint-config/heft-lint-flat-config-files_2026-09-12-04-00-00.json

@@ -0,0 +1,9 @@
+{
+  "changes": [
+    {
+      "packageName": "@rushstack/eslint-config",
+      "comment": "Group the profile's type-aware rules into an exported `typeAwareRules` set and add a `flat/without-type-information` helper for linting files that are not part of the TypeScript program with only the non-type-aware rules.",
+      "type": "minor"
+    }
+  ]
+}

common/changes/@rushstack/heft-lint-plugin/eslint-flat-config-files_2026-09-01-12-00-00.json

@@ -0,0 +1,9 @@
+{
+  "changes": [
+    {
+      "packageName": "@rushstack/heft-lint-plugin",
+      "comment": "Lint files selected by ESLint flat config even when they are not part of the TypeScript program.",
+      "type": "minor"
+    }
+  ]
+}

eslint/eslint-config/flat/profile/_common.js

@@ -183,6 +183,41 @@ const commonNamingConventionSelectors = [
   }
 ];
 
+// These are the only rules in this profile that require type information (i.e. the TypeScript program).
+// They are grouped separately so that TypeScript files which are NOT part of the project's TypeScript program
+// (for example config files or tests that are not included by tsconfig.json) can be linted with only the
+// non-type-aware rules.  See the "without-type-information" helper (flat/without-type-information.js), which
+// disables these rules and type-aware parsing for a given set of files.
+const typeAwareRules = {
+  // NOTE: This new rule replaces several deprecated rules from @typescript-eslint/eslint-plugin@2.3.3:
+  //
+  // - @typescript-eslint/camelcase
+  // - @typescript-eslint/class-name-casing
+  // - @typescript-eslint/interface-name-prefix
+  // - @typescript-eslint/member-naming
+  //
+  // Docs: https://github.com/typescript-eslint/typescript-eslint/blob/main/packages/eslint-plugin/docs/rules/naming-convention.md
+  '@typescript-eslint/naming-convention': [
+    'warn',
+    ...expandNamingConventionSelectors(commonNamingConventionSelectors)
+  ],
+
+  // RATIONALE:         The #1 rule of promises is that every promise chain must be terminated by a catch()
+  //                    handler.  Thus wherever a Promise arises, the code must either append a catch handler,
+  //                    or else return the object to a caller (who assumes this responsibility).  Unterminated
+  //                    promise chains are a serious issue.  Besides causing errors to be silently ignored,
+  //                    they can also cause a NodeJS process to terminate unexpectedly.
+  '@typescript-eslint/no-floating-promises': [
+    'error',
+    {
+      checkThenables: true
+    }
+  ],
+
+  // RATIONALE:         Catches a common coding mistake.
+  '@typescript-eslint/no-for-in-array': 'error'
+};
+
 const commonConfig = [
   // Manually authored .d.ts files are generally used to describe external APIs that are  not expected
   // to follow our coding conventions.  Linting those files tends to produce a lot of spurious suppressions,
@@ -291,18 +326,9 @@ const commonConfig = [
         }
       ],
 
-      // NOTE: This new rule replaces several deprecated rules from @typescript-eslint/eslint-plugin@2.3.3:
-      //
-      // - @typescript-eslint/camelcase
-      // - @typescript-eslint/class-name-casing
-      // - @typescript-eslint/interface-name-prefix
-      // - @typescript-eslint/member-naming
-      //
-      // Docs: https://github.com/typescript-eslint/typescript-eslint/blob/main/packages/eslint-plugin/docs/rules/naming-convention.md
-      '@typescript-eslint/naming-convention': [
-        'warn',
-        ...expandNamingConventionSelectors(commonNamingConventionSelectors)
-      ],
+      // Type-aware rules (require the TypeScript program) are grouped in typeAwareRules so that files outside
+      // the TypeScript program can be linted with only the non-type-aware rules.
+      ...typeAwareRules,
 
       // STANDARDIZED BY:   @typescript-eslint\eslint-plugin\dist\configs\recommended.json
       '@typescript-eslint/no-array-constructor': 'warn',
@@ -315,21 +341,6 @@ const commonConfig = [
       //                    may be more appropriate such as "unknown", "{}", or "Record<k,V>".
       '@typescript-eslint/no-explicit-any': 'warn',
 
-      // RATIONALE:         The #1 rule of promises is that every promise chain must be terminated by a catch()
-      //                    handler.  Thus wherever a Promise arises, the code must either append a catch handler,
-      //                    or else return the object to a caller (who assumes this responsibility).  Unterminated
-      //                    promise chains are a serious issue.  Besides causing errors to be silently ignored,
-      //                    they can also cause a NodeJS process to terminate unexpectedly.
-      '@typescript-eslint/no-floating-promises': [
-        'error',
-        {
-          checkThenables: true
-        }
-      ],
-
-      // RATIONALE:         Catches a common coding mistake.
-      '@typescript-eslint/no-for-in-array': 'error',
-
       // STANDARDIZED BY:   @typescript-eslint\eslint-plugin\dist\configs\recommended.json
       '@typescript-eslint/no-misused-new': 'error',
 
@@ -774,4 +785,4 @@ const commonConfig = [
   }
 ];
 
-module.exports = { commonNamingConventionSelectors, commonConfig };
+module.exports = { commonNamingConventionSelectors, commonConfig, typeAwareRules };

eslint/eslint-config/flat/without-type-information.js

@@ -0,0 +1,48 @@
+// Copyright (c) Microsoft Corporation. All rights reserved. Licensed under the MIT license.
+// See LICENSE in the project root for license information.
+
+// The profile's type-aware rules, turned off. Keep this in sync with the typeAwareRules group in
+// ./profile/_common.js.
+const disabledTypeAwareRules = {
+  '@typescript-eslint/naming-convention': 'off',
+  '@typescript-eslint/no-floating-promises': 'off',
+  '@typescript-eslint/no-for-in-array': 'off'
+};
+
+// Returns ESLint flat-config objects that lint the specified files WITHOUT type information: type-aware parsing
+// is disabled and the profile's type-aware rules are turned off, leaving only the non-type-aware rules in effect.
+//
+// Use this for TypeScript files that are selected by your ESLint configuration but are NOT part of the project's
+// TypeScript program -- for example configuration files or tests that are not included by tsconfig.json.  Without
+// this, typescript-eslint reports a fatal parsing error because it cannot associate those files with the project,
+// and any type-aware rule would be unable to run.
+//
+// IMPORTANT: These config objects must be included in your ESLint configuration AFTER the profile, so that they
+// override the profile's type-aware parser options and rules for the specified files.
+//
+// Example (eslint.config.js):
+//
+//   const { withoutTypeInformation } = require('@rushstack/eslint-config/flat/without-type-information');
+//
+//   module.exports = [
+//     ...nodeTrustedToolProfile,
+//     ...withoutTypeInformation({ files: ['tests/**/*.ts', 'playwright.config.ts'] })
+//   ];
+function withoutTypeInformation({ files }) {
+  return [
+    {
+      files,
+      languageOptions: {
+        parserOptions: {
+          // Disable type-aware parsing so that files outside the TypeScript program do not fail to resolve
+          // against it.
+          project: false,
+          projectService: false
+        }
+      },
+      rules: disabledTypeAwareRules
+    }
+  ];
+}
+
+module.exports = { withoutTypeInformation };