chore: run eslint with type information on CI (#13368)

Author: SimenB

.github/workflows/nodejs.yml

@@ -54,6 +54,8 @@ jobs:
         run: yarn typecheck:examples
       - name: typecheck tests
         run: yarn typecheck:tests
+      - name: run ESLint with type info
+        run: yarn lint-ts-files
 
   lint:
     name: Lint

e2e/__tests__/__snapshots__/moduleNameMapper.test.ts.snap

@@ -41,7 +41,7 @@ exports[`moduleNameMapper wrong array configuration 1`] = `
       12 | module.exports = () => 'test';
       13 |
 
-      at createNoMappedModuleFoundError (../../packages/jest-resolve/build/resolver.js:896:17)
+      at createNoMappedModuleFoundError (../../packages/jest-resolve/build/resolver.js:891:17)
       at Object.require (index.js:10:1)
       at Object.require (__tests__/index.js:10:20)"
 `;
@@ -71,7 +71,7 @@ exports[`moduleNameMapper wrong configuration 1`] = `
       12 | module.exports = () => 'test';
       13 |
 
-      at createNoMappedModuleFoundError (../../packages/jest-resolve/build/resolver.js:896:17)
+      at createNoMappedModuleFoundError (../../packages/jest-resolve/build/resolver.js:891:17)
       at Object.require (index.js:10:1)
       at Object.require (__tests__/index.js:10:20)"
 `;

package.json

@@ -103,6 +103,7 @@
     "lint:prettier-script": "prettier . \"!**/*.{js,jsx,cjs,mjs,ts,tsx}\" --cache",
     "lint:prettier": "yarn lint:prettier-script --write",
     "lint:prettier:ci": "yarn lint:prettier-script --check",
+    "lint-ts-files": "node scripts/lintTs.mjs",
     "remove-examples": "node ./scripts/remove-examples.mjs",
     "test-ci-partial": "yarn test-ci-partial:parallel -i",
     "test-ci-partial:parallel": "yarn jest --color --config jest.config.ci.mjs",

packages/babel-jest/src/__tests__/getCacheKey.test.ts

@@ -52,7 +52,8 @@ describe('getCacheKey', () => {
       readFileSync: () => 'new this file',
     }));
 
-    const {createTransformer}: typeof import('../index') = require('../index');
+    const {createTransformer} =
+      require('../index') as typeof import('../index');
 
     const newCacheKey = createTransformer().getCacheKey!(
       sourceText,
@@ -65,7 +66,7 @@ describe('getCacheKey', () => {
 
   test('if `babelOptions.options` value is changing', () => {
     jest.doMock('../loadBabelConfig', () => {
-      const babel: typeof import('@babel/core') = require('@babel/core');
+      const babel = require('@babel/core') as typeof import('@babel/core');
 
       return {
         loadPartialConfig: (options: BabelTransformOptions) => ({
@@ -75,7 +76,8 @@ describe('getCacheKey', () => {
       };
     });
 
-    const {createTransformer}: typeof import('../index') = require('../index');
+    const {createTransformer} =
+      require('../index') as typeof import('../index');
 
     const newCacheKey = createTransformer().getCacheKey!(
       sourceText,
@@ -117,7 +119,7 @@ describe('getCacheKey', () => {
 
   test('if `babelOptions.config` value is changing', () => {
     jest.doMock('../loadBabelConfig', () => {
-      const babel: typeof import('@babel/core') = require('@babel/core');
+      const babel = require('@babel/core') as typeof import('@babel/core');
 
       return {
         loadPartialConfig: (options: BabelTransformOptions) => ({
@@ -127,7 +129,8 @@ describe('getCacheKey', () => {
       };
     });
 
-    const {createTransformer}: typeof import('../index') = require('../index');
+    const {createTransformer} =
+      require('../index') as typeof import('../index');
 
     const newCacheKey = createTransformer().getCacheKey!(
       sourceText,
@@ -140,7 +143,7 @@ describe('getCacheKey', () => {
 
   test('if `babelOptions.babelrc` value is changing', () => {
     jest.doMock('../loadBabelConfig', () => {
-      const babel: typeof import('@babel/core') = require('@babel/core');
+      const babel = require('@babel/core') as typeof import('@babel/core');
 
       return {
         loadPartialConfig: (options: BabelTransformOptions) => ({
@@ -150,7 +153,8 @@ describe('getCacheKey', () => {
       };
     });
 
-    const {createTransformer}: typeof import('../index') = require('../index');
+    const {createTransformer} =
+      require('../index') as typeof import('../index');
 
     const newCacheKey = createTransformer().getCacheKey!(
       sourceText,

packages/babel-jest/src/__tests__/index.ts

@@ -13,14 +13,17 @@ import {makeProjectConfig} from '@jest/test-utils';
 import type {TransformOptions} from '@jest/transform';
 import babelJest, {createTransformer} from '../index';
 import {loadPartialConfig} from '../loadBabelConfig';
+
 jest.mock('../loadBabelConfig', () => {
   const actual =
     jest.requireActual<typeof import('@babel/core')>('@babel/core');
 
   return {
-    loadPartialConfig: jest.fn((...args) => actual.loadPartialConfig(...args)),
-    loadPartialConfigAsync: jest.fn((...args) =>
-      actual.loadPartialConfigAsync(...args),
+    loadPartialConfig: jest.fn<typeof actual.loadPartialConfig>((...args) =>
+      actual.loadPartialConfig(...args),
+    ),
+    loadPartialConfigAsync: jest.fn<typeof actual.loadPartialConfigAsync>(
+      (...args) => actual.loadPartialConfigAsync(...args),
     ),
   };
 });
@@ -69,7 +72,7 @@ test('Returns source string with inline maps when no transformOptions is passed'
 });
 
 test('Returns source string with inline maps when no transformOptions is passed async', async () => {
-  const result: any = await defaultBabelJestTransformer.processAsync!(
+  const result = await defaultBabelJestTransformer.processAsync!(
     sourceString,
     'dummy_path.js',
     {
@@ -86,8 +89,18 @@ test('Returns source string with inline maps when no transformOptions is passed
   expect(result.map).toBeDefined();
   expect(result.code).toMatch('//# sourceMappingURL');
   expect(result.code).toMatch('customMultiply');
-  expect(result.map!.sources).toEqual(['dummy_path.js']);
-  expect(JSON.stringify(result.map!.sourcesContent)).toMatch('customMultiply');
+
+  const {map} = result;
+
+  expect(map).toBeTruthy();
+  expect(typeof map).not.toBe('string');
+
+  if (map == null || typeof map === 'string') {
+    throw new Error('dead code');
+  }
+
+  expect(map.sources).toEqual(['dummy_path.js']);
+  expect(JSON.stringify(map.sourcesContent)).toMatch('customMultiply');
 });
 
 describe('caller option correctly merges from defaults and options', () => {

packages/babel-jest/src/index.ts

@@ -51,7 +51,7 @@ function addIstanbulInstrumentation(
     const copiedBabelOptions: TransformOptions = {...babelOptions};
     copiedBabelOptions.auxiliaryCommentBefore = ' istanbul ignore next ';
     // Copied from jest-runtime transform.js
-    copiedBabelOptions.plugins = (copiedBabelOptions.plugins || []).concat([
+    copiedBabelOptions.plugins = (copiedBabelOptions.plugins ?? []).concat([
       [
         babelIstanbulPlugin,
         {
@@ -76,7 +76,7 @@ function getCacheKeyFromConfig(
 ): string {
   const {config, configString, instrument} = transformOptions;
 
-  const configPath = [babelOptions.config || '', babelOptions.babelrc || ''];
+  const configPath = [babelOptions.config ?? '', babelOptions.babelrc ?? ''];
 
   return createHash('sha256')
     .update(THIS_FILE)
@@ -93,9 +93,9 @@ function getCacheKeyFromConfig(
     .update('\0', 'utf8')
     .update(instrument ? 'instrument' : '')
     .update('\0', 'utf8')
-    .update(process.env.NODE_ENV || '')
+    .update(process.env.NODE_ENV ?? '')
     .update('\0', 'utf8')
-    .update(process.env.BABEL_ENV || '')
+    .update(process.env.BABEL_ENV ?? '')
     .update('\0', 'utf8')
     .update(process.version)
     .digest('hex')

packages/babel-plugin-jest-hoist/src/index.ts

@@ -114,10 +114,10 @@ const IDVisitor = {
   ],
 };
 
-const FUNCTIONS: Record<
+const FUNCTIONS = Object.create(null) as Record<
   string,
   <T extends Node>(args: Array<NodePath<T>>) => boolean
-> = Object.create(null);
+>;
 
 FUNCTIONS.mock = args => {
   if (args.length === 1) {
@@ -142,7 +142,7 @@ FUNCTIONS.mock = args => {
       let scope = id.scope;
 
       while (scope !== parentScope) {
-        if (scope.bindings[name]) {
+        if (scope.bindings[name] != null) {
           found = true;
           break;
         }

packages/diff-sequences/src/__tests__/index.property.test.ts

@@ -27,7 +27,7 @@ const findCommonItems = (a: Array<string>, b: Array<string>): Array<string> => {
 const extractCount = (data: Array<string>): Map<string, number> => {
   const countPerChar = new Map<string, number>();
   for (const item of data) {
-    const currentCount = countPerChar.get(item) || 0;
+    const currentCount = countPerChar.get(item) ?? 0;
     countPerChar.set(item, currentCount + 1);
   }
   return countPerChar;
@@ -93,7 +93,7 @@ it('should have at most the same number of each character as its inputs', () =>
       const commonCount = extractCount(commonItems);
       const aCount = extractCount(a);
       for (const [item, count] of commonCount) {
-        const countOfItemInA = aCount.get(item) || 0;
+        const countOfItemInA = aCount.get(item) ?? 0;
         expect(countOfItemInA).toBeGreaterThanOrEqual(count);
       }
     }),

packages/diff-sequences/src/__tests__/index.test.ts

@@ -15,7 +15,8 @@ describe('invalid arg', () => {
   describe('length', () => {
     test('is not a number', () => {
       expect(() => {
-        diff('0' as any, 0, isCommon, foundSubsequence);
+        // @ts-expect-error: Testing runtime errors here
+        diff('0', 0, isCommon, foundSubsequence);
       }).toThrow(/aLength/);
     });
     test('Infinity is not a safe integer', () => {
@@ -49,12 +50,14 @@ describe('invalid arg', () => {
   describe('callback', () => {
     test('null is not a function', () => {
       expect(() => {
-        diff(0, 0, null as any, foundSubsequence);
+        // @ts-expect-error: Testing runtime errors here
+        diff(0, 0, null, foundSubsequence);
       }).toThrow(/isCommon/);
     });
     test('undefined is not a function', () => {
       expect(() => {
-        diff(0, 0, isCommon, undefined as any);
+        // @ts-expect-error: Testing runtime errors here
+        diff(0, 0, isCommon, undefined);
       }).toThrow(/foundSubsequence/);
     });
   });

packages/expect-utils/src/jasmineUtils.ts

@@ -211,9 +211,7 @@ function keys(obj: object, hasKey: (obj: object, key: string) => boolean) {
   }
   return keys.concat(
     (Object.getOwnPropertySymbols(obj) as Array<any>).filter(
-      symbol =>
-        (Object.getOwnPropertyDescriptor(obj, symbol) as PropertyDescriptor)
-          .enumerable,
+      symbol => Object.getOwnPropertyDescriptor(obj, symbol)!.enumerable,
     ),
   );
 }