chore(lint): add enforce-ts-extension oxlint rule (renovatebot#42389)

zharinov · astellingwerf · web-flow · commit 7df11ed73484 · 2026-04-07T15:36:16.000Z
* refactor(lint): extract custom oxlint rules into separate files

Split `tools/lint/rules.js` into one file per rule under
`tools/lint/rules/`. Also simplify `test-root-describe` with
early-exit guard clauses.

* feat(lint): add `enforce-ts-extension` oxlint rule

Add a custom JS-based oxlint rule that enforces `.ts` extensions on
local imports. The rule catches two problems:

- `.js` extension used instead of `.ts` (auto-fixable)
- missing file extension entirely (report only)

Checked locations:
- static import/export declarations
- dynamic `import()` expressions
- vitest module APIs: `vi.mock`, `vi.doMock`, `vi.unmock`,
  `vi.doUnmock`, `vi.importActual`, `vi.importMock`

Both relative paths (`./`, `../`) and path aliases (`~test/`)
are treated as local. Package imports are ignored.

Also fixes 26 pre-existing violations across 18 spec files.

* Update tools/lint/rules/enforce-ts-extension.js

Co-authored-by: Anne Stellingwerf &lt;1637358+astellingwerf@users.noreply.github.com&gt;

---------

Co-authored-by: Anne Stellingwerf &lt;1637358+astellingwerf@users.noreply.github.com&gt;
diff --git a/.oxlintrc.json b/.oxlintrc.json
@@ -47,6 +47,7 @@
     ],
     "no-unassigned-vars": "error",
 
+    "renovate/enforce-ts-extension": "error",
     "renovate/no-tools-import": "error",
 
     "typescript/await-thenable": "error",
@@ -193,7 +194,8 @@
       "files": ["**/*.js", "**/*.mjs", "**/*.cjs"],
       "rules": {
         "typescript/restrict-template-expressions": "off",
-        "typescript/explicit-function-return-type": "off"
+        "typescript/explicit-function-return-type": "off",
+        "renovate/enforce-ts-extension": "off"
       }
     }
   ],
diff --git a/lib/config/options/index.spec.ts b/lib/config/options/index.spec.ts
@@ -3,7 +3,7 @@ import * as manager from '../../modules/manager/index.ts';
 import * as platform from '../../modules/platform/index.ts';
 import { getOptions } from './index.ts';
 
-vi.unmock('../../modules/platform');
+vi.unmock('../../modules/platform/index.ts');
 
 describe('config/options/index', () => {
   it('test manager should have no defaultConfig', () => {
diff --git a/lib/logger/index.spec.ts b/lib/logger/index.spec.ts
@@ -26,7 +26,7 @@ import type { RenovateLogger } from './renovate-logger.ts';
 
 const logContext = 'initial_context';
 
-vi.unmock('.');
+vi.unmock('./index.ts');
 vi.mock('node:crypto', () => ({
   randomUUID: vi.fn(() => 'initial_context'),
 }));
diff --git a/lib/logger/once.spec.ts b/lib/logger/once.spec.ts
@@ -1,7 +1,7 @@
 import { init, logger } from './index.ts';
 import { once, reset } from './once.ts';
 
-vi.unmock('.');
+vi.unmock('./index.ts');
 
 // init logger
 await init();
diff --git a/lib/modules/datasource/crate/index.spec.ts b/lib/modules/datasource/crate/index.spec.ts
@@ -18,7 +18,7 @@ import { getPkgReleases } from '../index.ts';
 import { CrateDatasource } from './index.ts';
 import type { RegistryConfigSchema } from './schema.ts';
 
-vi.unmock('../../../util/mutex');
+vi.unmock('../../../util/mutex.ts');
 vi.mock('simple-git');
 const simpleGit = vi.mocked(_simpleGit);
 
diff --git a/lib/modules/datasource/deb/index.spec.ts b/lib/modules/datasource/deb/index.spec.ts
@@ -19,7 +19,7 @@ import {
   getRegistryUrl,
 } from './url.ts';
 
-vi.unmock('../../../util/mutex');
+vi.unmock('../../../util/mutex.ts');
 
 const debBaseUrl = 'http://deb.debian.org';
 
diff --git a/lib/modules/manager/nuget/artifacts.spec.ts b/lib/modules/manager/nuget/artifacts.spec.ts
@@ -32,10 +32,9 @@ const config: UpdateArtifactsConfig = {};
 
 describe('modules/manager/nuget/artifacts', () => {
   beforeEach(async () => {
-    const realFs =
-      await vi.importActual<typeof import('../../../util/fs/index.ts')>(
-        '../../../util/fs',
-      );
+    const realFs = await vi.importActual<
+      typeof import('../../../util/fs/index.ts')
+    >('../../../util/fs/index.ts');
     hostRules.find.mockReturnValue({});
     getDefaultRegistries.mockReturnValue([
       { url: nugetOrg, name: 'nuget.org' },
diff --git a/lib/modules/platform/azure/azure-helper.spec.ts b/lib/modules/platform/azure/azure-helper.spec.ts
@@ -16,7 +16,7 @@ describe('modules/platform/azure/azure-helper', () => {
     // reset module
     vi.resetModules();
     azureHelper = await vi.importActual('./azure-helper.ts');
-    azureApi = await vi.importMock('./azure-got-wrapper');
+    azureApi = await vi.importMock('./azure-got-wrapper.ts');
   });
 
   describe('getRef', () => {
diff --git a/lib/modules/platform/bitbucket-server/utils.spec.ts b/lib/modules/platform/bitbucket-server/utils.spec.ts
@@ -13,7 +13,7 @@ import {
   getRepoGitUrl,
 } from './utils.ts';
 
-vi.unmock('../../../util/git');
+vi.unmock('../../../util/git/index.ts');
 
 function sshLink(projectKey: string, repositorySlug: string): string {
   return `ssh://git@stash.renovatebot.com:7999/${projectKey.toLowerCase()}/${repositorySlug}.git`;
diff --git a/lib/modules/platform/index.spec.ts b/lib/modules/platform/index.spec.ts
@@ -6,8 +6,8 @@ import api from './api.ts';
 import * as platform from './index.ts';
 import type { Platform } from './types.ts';
 
-vi.unmock('.');
-vi.unmock('./scm');
+vi.unmock('./index.ts');
+vi.unmock('./scm.ts');
 
 describe('modules/platform/index', () => {
   beforeEach(() => {
diff --git a/lib/modules/platform/scm-manager/index.spec.ts b/lib/modules/platform/scm-manager/index.spec.ts
@@ -9,8 +9,8 @@ import { mapPrFromScmToRenovate } from './mapper.ts';
 import type { PullRequest, Repo, User } from './schema.ts';
 import type { PrFilterByState } from './types.ts';
 
-vi.mock('../util');
-vi.mock('../../../util/git');
+vi.mock('../util.ts');
+vi.mock('../../../util/git/index.ts');
 
 const endpoint = 'https://localhost:8080/scm/';
 const baseUrl = `${endpoint}api/v2`;
diff --git a/lib/modules/platform/scm.spec.ts b/lib/modules/platform/scm.spec.ts
@@ -3,7 +3,7 @@ import { PLATFORM_NOT_FOUND } from '../../constants/error-messages.ts';
 import type { PlatformId } from '../../constants/index.ts';
 import { scm, setPlatformScmApi } from './scm.ts';
 
-vi.unmock('./scm'); //mocked from test/setup
+vi.unmock('./scm.ts'); //mocked from test/setup
 
 describe('modules/platform/scm', () => {
   it('no platform chosen', () => {
diff --git a/lib/util/exec/common.spec.ts b/lib/util/exec/common.spec.ts
@@ -16,7 +16,7 @@ import type { DataListener, RawExecOptions } from './types.ts';
 vi.mock('../../instrumentation/index.ts');
 vi.mock('node:child_process');
 vi.mock('execa');
-vi.unmock('./common');
+vi.unmock('./common.ts');
 
 const instrument = vi.spyOn(_instrumentation, 'instrument');
 const execa = vi.mocked(_execa);
diff --git a/lib/util/git/index.spec.ts b/lib/util/git/index.spec.ts
@@ -20,13 +20,13 @@ import { setNoVerify } from './index.ts';
 import * as _modifiedCache from './modified-cache.ts';
 import type { FileChange } from './types.ts';
 
-vi.mock('./conflicts-cache');
-vi.mock('./behind-base-branch-cache');
-vi.mock('./modified-cache');
+vi.mock('./conflicts-cache.ts');
+vi.mock('./behind-base-branch-cache.ts');
+vi.mock('./modified-cache.ts');
 vi.mock('timers/promises');
-vi.mock('../cache/repository');
-vi.mock('./auth');
-vi.unmock('.');
+vi.mock('../cache/repository/index.ts');
+vi.mock('./auth.ts');
+vi.unmock('./index.ts');
 
 const behindBaseCache = vi.mocked(_behindBaseCache);
 const conflictsCache = vi.mocked(_conflictsCache);
diff --git a/lib/util/mutex.spec.ts b/lib/util/mutex.spec.ts
@@ -1,6 +1,6 @@
 import { acquireLock, getMutex } from './mutex.ts';
 
-vi.unmock('./mutex');
+vi.unmock('./mutex.ts');
 
 describe('util/mutex', () => {
   describe('getMutex', () => {
diff --git a/lib/workers/global/autodiscover.spec.ts b/lib/workers/global/autodiscover.spec.ts
@@ -6,8 +6,8 @@ import { autodiscoverRepositories } from './autodiscover.ts';
 
 vi.mock('../../modules/platform/github/index.ts');
 vi.mock('../../util/host-rules.ts');
-vi.unmock('../../modules/platform');
-vi.unmock('../../modules/platform/scm');
+vi.unmock('../../modules/platform/index.ts');
+vi.unmock('../../modules/platform/scm.ts');
 
 // imports are readonly
 const hostRules = vi.mocked(_hostRules);
diff --git a/lib/workers/global/index.spec.ts b/lib/workers/global/index.spec.ts
@@ -33,7 +33,7 @@ vi.mock('fs-extra', async () => {
 });
 
 // TODO: why do we need git here?
-vi.unmock('../../util/git');
+vi.unmock('../../util/git/index.ts');
 
 const addSecretForSanitizing = vi.spyOn(secrets, 'addSecretForSanitizing');
 const parseConfigs = vi.spyOn(configParser, 'parseConfigs');
diff --git a/lib/workers/repository/init/index.spec.ts b/lib/workers/repository/init/index.spec.ts
@@ -19,7 +19,7 @@ vi.mock('../../../modules/platform/index.ts', () => ({
   platform: { initRepo: vi.fn() },
   getPlatformList: vi.fn(),
 }));
-vi.unmock('../../../util/mutex');
+vi.unmock('../../../util/mutex.ts');
 
 const apis = vi.mocked(_apis);
 const config = vi.mocked(_config);
diff --git a/lib/workers/repository/process/limits.spec.ts b/lib/workers/repository/process/limits.spec.ts
@@ -6,7 +6,7 @@ import * as _repositoryCache from '../../../util/cache/repository/index.ts';
 import type { BranchConfig } from '../../types.ts';
 import * as limits from './limits.ts';
 
-vi.mock('../../../util/cache/repository');
+vi.mock('../../../util/cache/repository/index.ts');
 const repositoryCache = vi.mocked(_repositoryCache);
 
 let config: RenovateConfig;
diff --git a/tools/lint/rules.js b/tools/lint/rules.js
@@ -1,3 +1,4 @@
+import enforceTsExtension from './rules/enforce-ts-extension.js';
 import noToolsImport from './rules/no-tools-import.js';
 import testRootDescribe from './rules/test-root-describe.js';
 
@@ -6,6 +7,7 @@ export default {
     name: 'renovate',
   },
   rules: {
+    'enforce-ts-extension': enforceTsExtension,
     'no-tools-import': noToolsImport,
     'test-root-describe': testRootDescribe,
   },
diff --git a/tools/lint/rules/enforce-ts-extension.js b/tools/lint/rules/enforce-ts-extension.js
@@ -0,0 +1,132 @@
+const VI_METHODS = new Set([
+  'mock',
+  'doMock',
+  'unmock',
+  'doUnmock',
+  'importActual',
+  'importMock',
+]);
+
+/** @param {string} value */
+function isLocalPath(value) {
+  return value.startsWith('.') || value.startsWith('~');
+}
+
+/** @param {string} value */
+function hasExtension(value) {
+  const lastSlash = value.lastIndexOf('/');
+  const basename = lastSlash >= 0 ? value.slice(lastSlash + 1) : value;
+  const dotIndex = basename.lastIndexOf('.');
+  return dotIndex > 0 && dotIndex < basename.length - 1;
+}
+
+/**
+ * @param {import('estree').Literal} node
+ * @returns {string | undefined}
+ */
+function getStringValue(node) {
+  if (typeof node.value === 'string') {
+    return node.value;
+  }
+  return undefined;
+}
+
+/**
+ * @param {import('eslint').Rule.RuleContext} context
+ * @param {import('estree').Literal} node
+ * @param {string} value
+ */
+function reportJsExtension(context, node, value) {
+  const quote = node.raw?.[0] ?? "'";
+  const fixed = value.slice(0, -3) + '.ts';
+  context.report({
+    node,
+    messageId: 'useTsExtension',
+    fix(fixer) {
+      return fixer.replaceText(node, `${quote}${fixed}${quote}`);
+    },
+  });
+}
+
+/**
+ * @param {import('eslint').Rule.RuleContext} context
+ * @param {import('estree').Literal} node
+ */
+function reportMissingExtension(context, node) {
+  context.report({
+    node,
+    messageId: 'missingExtension',
+  });
+}
+
+/**
+ * @param {import('eslint').Rule.RuleContext} context
+ * @param {import('estree').Literal | null | undefined} sourceNode
+ */
+function checkLiteral(context, sourceNode) {
+  if (!sourceNode) {
+    return;
+  }
+  const value = getStringValue(sourceNode);
+  if (!value || !isLocalPath(value)) {
+    return;
+  }
+  if (value.endsWith('.js')) {
+    reportJsExtension(context, sourceNode, value);
+  }
+}
+
+/** @type {import('eslint').Rule.RuleModule} */
+export default {
+  meta: {
+    type: 'problem',
+    fixable: 'code',
+    messages: {
+      useTsExtension: 'Use ".ts" extension instead of ".js" for local imports',
+      missingExtension: 'Missing file extension on local import',
+    },
+  },
+  create(context) {
+    return {
+      ImportDeclaration(node) {
+        checkLiteral(context, node.source);
+      },
+      ExportNamedDeclaration(node) {
+        checkLiteral(context, node.source);
+      },
+      ExportAllDeclaration(node) {
+        checkLiteral(context, node.source);
+      },
+      ImportExpression(node) {
+        if (node.source.type === 'Literal') {
+          checkLiteral(context, node.source);
+        }
+      },
+      CallExpression(node) {
+        const { callee } = node;
+        if (
+          callee.type !== 'MemberExpression' ||
+          callee.object.type !== 'Identifier' ||
+          callee.object.name !== 'vi' ||
+          callee.property.type !== 'Identifier' ||
+          !VI_METHODS.has(callee.property.name)
+        ) {
+          return;
+        }
+        const [arg] = node.arguments;
+        if (arg?.type !== 'Literal') {
+          return;
+        }
+        const value = getStringValue(arg);
+        if (!value || !isLocalPath(value)) {
+          return;
+        }
+        if (value.endsWith('.js')) {
+          reportJsExtension(context, arg, value);
+        } else if (!hasExtension(value)) {
+          reportMissingExtension(context, arg);
+        }
+      },
+    };
+  },
+};
