Test ESLint configs

.eslintrc.js

@@ -5,7 +5,11 @@ module.exports = {
     ecmaVersion: 2018,
   },
 
-  extends: ['@metamask/eslint-config', '@metamask/eslint-config-nodejs'],
+  extends: [
+    '@metamask/eslint-config',
+    '@metamask/eslint-config-nodejs',
+    '@metamask/eslint-config-jest',
+  ],
 
   rules: {
     'import/no-dynamic-require': 'off',

.github/workflows/lint-test.yml

@@ -50,6 +50,31 @@ jobs:
             exit 1
           fi
 
+  test:
+    name: Test
+    runs-on: ubuntu-latest
+    needs:
+      - prepare
+    strategy:
+      matrix:
+        node-version: [14.x, 16.x, 18.x, 19.x]
+    steps:
+      - uses: actions/checkout@v3
+      - name: Use Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v3
+        with:
+          node-version: ${{ matrix.node-version }}
+          cache: 'yarn'
+      - run: yarn --immutable --immutable-cache
+      - run: yarn test
+      - name: Require clean working directory
+        shell: bash
+        run: |
+          if ! git diff --exit-code; then
+            echo "Working tree dirty at end of job"
+            exit 1
+          fi
+
   check-workflows:
     name: Check workflows
     runs-on: ubuntu-latest
@@ -68,6 +93,7 @@ jobs:
     runs-on: ubuntu-latest
     needs:
       - lint
+      - test
       - check-workflows
     steps:
       - run: echo "Great success!"

jest.config.js

@@ -0,0 +1,201 @@
+/*
+ * For a detailed explanation regarding each configuration property and type check, visit:
+ * https://jestjs.io/docs/configuration
+ */
+
+module.exports = {
+  // All imported modules in your tests should be mocked automatically
+  // automock: false,
+
+  // Stop running tests after `n` failures
+  // bail: 0,
+
+  // The directory where Jest should store its cached dependency information
+  // cacheDirectory: "/private/var/folders/fk/c3y07g0576j8_2s9m01pk4qw0000gn/T/jest_dx",
+
+  // Automatically clear mock calls, instances and results before every test.
+  // This does not remove any mock implementation that may have been provided,
+  // so we disable it.
+  // clearMocks: true,
+
+  // Indicates whether the coverage information should be collected while executing the test
+  collectCoverage: false,
+
+  // An array of glob patterns indicating a set of files for which coverage information should be collected
+  // collectCoverageFrom: [],
+
+  // The directory where Jest should output its coverage files
+  // coverageDirectory: 'coverage',
+
+  // An array of regexp pattern strings used to skip coverage collection
+  // coveragePathIgnorePatterns: [
+  //   "/node_modules/"
+  // ],
+
+  // Indicates which provider should be used to instrument code for coverage
+  // coverageProvider: 'v8',
+
+  // A list of reporter names that Jest uses when writing coverage reports
+  // coverageReporters: ['html', 'json-summary', 'text'],
+
+  // An object that configures minimum threshold enforcement for coverage results
+  // coverageThreshold: {
+  //   global: {
+  //     branches: 100,
+  //     functions: 100,
+  //     lines: 100,
+  //     statements: 100,
+  //   },
+  // },
+
+  // A path to a custom dependency extractor
+  // dependencyExtractor: undefined,
+
+  // Make calling deprecated APIs throw helpful error messages
+  // errorOnDeprecated: false,
+
+  // Force coverage collection from ignored files using an array of glob patterns
+  // forceCoverageMatch: [],
+
+  // A path to a module which exports an async function that is triggered once before all test suites
+  // globalSetup: undefined,
+
+  // A path to a module which exports an async function that is triggered once after all test suites
+  // globalTeardown: undefined,
+
+  // A set of global variables that need to be available in all test environments
+  // globals: {},
+
+  // The maximum amount of workers used to run your tests. Can be specified as % or a number. E.g. maxWorkers: 10% will use 10% of your CPU amount + 1 as the maximum worker number. maxWorkers: 2 will use a maximum of 2 workers.
+  // maxWorkers: "50%",
+
+  // An array of directory names to be searched recursively up from the requiring module's location
+  // moduleDirectories: [
+  //   "node_modules"
+  // ],
+
+  // An array of file extensions your modules use
+  // moduleFileExtensions: [
+  //   "js",
+  //   "jsx",
+  //   "ts",
+  //   "tsx",
+  //   "json",
+  //   "node"
+  // ],
+
+  // A map from regular expressions to module names or to arrays of module names that allow to stub out resources with a single module
+  // moduleNameMapper: {},
+
+  // An array of regexp pattern strings, matched against all module paths before considered 'visible' to the module loader
+  // modulePathIgnorePatterns: [],
+
+  // Activates notifications for test results
+  // notify: false,
+
+  // An enum that specifies notification mode. Requires { notify: true }
+  // notifyMode: "failure-change",
+
+  // Run tests from one or more projects
+  projects: ['packages/*'],
+
+  // Use this configuration option to add custom reporters to Jest
+  // reporters: undefined,
+
+  // "resetMocks" resets all mocks, including mocked modules, to jest.fn(),
+  // between each test case.
+  resetMocks: true,
+
+  // Reset the module registry before running each individual test
+  // resetModules: false,
+
+  // A path to a custom resolver
+  // resolver: undefined,
+
+  // "restoreMocks" restores all mocks created using jest.spyOn to their
+  // original implementations, between each test. It does not affect mocked
+  // modules.
+  restoreMocks: true,
+
+  // The root directory that Jest should scan for tests and modules within
+  // rootDir: undefined,
+
+  // A list of paths to directories that Jest should use to search for files in
+  // roots: [
+  //   "<rootDir>"
+  // ],
+
+  // Allows you to use a custom runner instead of Jest's default test runner
+  // runner: "jest-runner",
+
+  // The paths to modules that run some code to configure or set up the testing environment before each test
+  // setupFiles: [],
+
+  // A list of paths to modules that run some code to configure or set up the testing framework before each test
+  // setupFilesAfterEnv: [],
+
+  // The number of seconds after which a test is considered as slow and reported as such in the results.
+  // slowTestThreshold: 5,
+
+  // A list of paths to snapshot serializer modules Jest should use for snapshot testing
+  // snapshotSerializers: [],
+
+  // The test environment that will be used for testing
+  // testEnvironment: "jest-environment-node",
+
+  // Options that will be passed to the testEnvironment
+  // testEnvironmentOptions: {},
+
+  // Adds a location field to test results
+  // testLocationInResults: false,
+
+  // The glob patterns Jest uses to detect test files
+  // testMatch: [
+  //   "**/__tests__/**/*.[jt]s?(x)",
+  //   "**/?(*.)+(spec|test).[tj]s?(x)"
+  // ],
+
+  // An array of regexp pattern strings that are matched against all test paths, matched tests are skipped
+  // testPathIgnorePatterns: [
+  //   "/node_modules/"
+  // ],
+
+  // The regexp pattern or array of patterns that Jest uses to detect test files
+  // testRegex: [],
+
+  // This option allows the use of a custom results processor
+  // testResultsProcessor: undefined,
+
+  // This option allows use of a custom test runner
+  // testRunner: "jest-circus/runner",
+
+  // Reduce the default test timeout from 5s to 2.5s
+  testTimeout: 2500,
+
+  // This option sets the URL for the jsdom environment. It is reflected in properties such as location.href
+  // testURL: "http://localhost",
+
+  // Setting this value to "fake" allows the use of fake timers for functions such as "setTimeout"
+  // timers: "real",
+
+  // A map from regular expressions to paths to transformers
+  // transform: undefined,
+
+  // An array of regexp pattern strings that are matched against all source file paths, matched files will skip transformation
+  // transformIgnorePatterns: [
+  //   "/node_modules/",
+  //   "\\.pnp\\.[^\\/]+$"
+  // ],
+
+  // An array of regexp pattern strings that are matched against all modules before the module loader will automatically return a mock for them
+  // unmockedModulePathPatterns: undefined,
+
+  // Indicates whether each individual test should be reported during the run
+  // verbose: undefined,
+
+  // An array of regexp patterns that are matched against all source file paths before re-running tests in watch mode
+  // watchPathIgnorePatterns: [],
+
+  // Whether to use watchman for file crawling
+  // watchman: true,
+};

package.json

@@ -15,7 +15,8 @@
     "lint:config-validation": "node ./scripts/validate-configs.js",
     "lint:eslint": "yarn eslint . --ext ts,js",
     "lint:fix": "yarn lint:eslint --fix && yarn lint:misc --write && yarn lint:config-validation --write",
-    "lint:misc": "prettier '**/*.json' '!**/rules-snapshot.json' '**/*.md' '!**/CHANGELOG.md' '**/*.yml' '!.yarnrc.yml' --ignore-path .gitignore"
+    "lint:misc": "prettier '**/*.json' '!**/rules-snapshot.json' '**/*.md' '!**/CHANGELOG.md' '**/*.yml' '!.yarnrc.yml' --ignore-path .gitignore",
+    "test": "jest"
   },
   "resolutions": {
     "eslint@^8.27.0": "patch:eslint@npm%3A8.27.0#./.yarn/patches/eslint-npm-8.27.0-2f252732ca.patch"
@@ -27,13 +28,16 @@
     "@metamask/eslint-config": "*",
     "@metamask/eslint-config-nodejs": "*",
     "@metamask/utils": "^3.3.1",
+    "@types/jest": "^29.2.2",
     "eslint": "^8.27.0",
     "eslint-config-prettier": "^8.5.0",
     "eslint-plugin-import": "^2.26.0",
+    "eslint-plugin-jest": "^27.1.5",
     "eslint-plugin-jsdoc": "^39.6.2",
     "eslint-plugin-node": "^11.1.0",
     "eslint-plugin-prettier": "^4.2.1",
     "fast-deep-equal": "^3.1.3",
+    "jest": "^29.3.1",
     "prettier": "^2.7.1",
     "prettier-plugin-packagejson": "^2.2.18"
   },

packages/base/jest.config.js

@@ -0,0 +1,5 @@
+const packageJson = require('./package.json');
+
+module.exports = {
+  displayName: packageJson.name,
+};

packages/base/src/index.test.js

@@ -0,0 +1,18 @@
+const { ESLint } = require('eslint');
+
+const config = require('.');
+
+describe('index', () => {
+  it('is a valid ESLint config', async () => {
+    const api = new ESLint({
+      baseConfig: config,
+      useEslintrc: false,
+    });
+
+    const result = await api.lintText(`console.log('Hello, world!');\n`);
+
+    expect(result[0].messages).toStrictEqual([]);
+    expect(result[0].warningCount).toBe(0);
+    expect(result[0].errorCount).toBe(0);
+  });
+});

packages/jest/jest.config.js

@@ -0,0 +1,5 @@
+const packageJson = require('./package.json');
+
+module.exports = {
+  displayName: packageJson.name,
+};

packages/jest/src/index.test.js

@@ -0,0 +1,18 @@
+const { ESLint } = require('eslint');
+
+const config = require('.');
+
+describe('index', () => {
+  it('is a valid ESLint config', async () => {
+    const api = new ESLint({
+      baseConfig: config,
+      useEslintrc: false,
+    });
+
+    const result = await api.lintText(`console.log('Hello, world!');\n`);
+
+    expect(result[0].messages).toStrictEqual([]);
+    expect(result[0].warningCount).toBe(0);
+    expect(result[0].errorCount).toBe(0);
+  });
+});

packages/mocha/jest.config.js

@@ -0,0 +1,5 @@
+const packageJson = require('./package.json');
+
+module.exports = {
+  displayName: packageJson.name,
+};

packages/mocha/src/index.test.js

@@ -0,0 +1,18 @@
+const { ESLint } = require('eslint');
+
+const config = require('.');
+
+describe('index', () => {
+  it('is a valid ESLint config', async () => {
+    const api = new ESLint({
+      baseConfig: config,
+      useEslintrc: false,
+    });
+
+    const result = await api.lintText(`console.log('Hello, world!');\n`);
+
+    expect(result[0].messages).toStrictEqual([]);
+    expect(result[0].warningCount).toBe(0);
+    expect(result[0].errorCount).toBe(0);
+  });
+});

packages/nodejs/jest.config.js

@@ -0,0 +1,5 @@
+const packageJson = require('./package.json');
+
+module.exports = {
+  displayName: packageJson.name,
+};

packages/nodejs/src/index.test.js

@@ -0,0 +1,18 @@
+const { ESLint } = require('eslint');
+
+const config = require('.');
+
+describe('index', () => {
+  it('is a valid ESLint config', async () => {
+    const api = new ESLint({
+      baseConfig: config,
+      useEslintrc: false,
+    });
+
+    const result = await api.lintText(`console.log('Hello, world!');\n`);
+
+    expect(result[0].messages).toStrictEqual([]);
+    expect(result[0].warningCount).toBe(0);
+    expect(result[0].errorCount).toBe(0);
+  });
+});

packages/typescript/jest.config.js

@@ -0,0 +1,5 @@
+const packageJson = require('./package.json');
+
+module.exports = {
+  displayName: packageJson.name,
+};