Add forceCoverageMatch configuration option (#5081)

Add forceCoverageMatch config option to allow collecting coverage even
if the file is ignored. This way you can collect coverage from the
source files with tests or specific files you ignored manually.

CHANGELOG.md

@@ -1,6 +1,7 @@
 ## master
 
-None
+* `[jest-config]` Add `forceCoverageMatch` to allow collecting coverage from
+  ignored files. ([#5081](https://github.com/facebook/jest/pull/5081))
 
 ## jest 22.0.0
 

docs/Configuration.md

@@ -237,6 +237,41 @@ Jest will fail if:
 * The `./src/api/very-important-module.js` file has less than 100% coverage.
 * Every remaining file combined has less than 50% coverage (`global`).
 
+### `forceCoverageMatch` [array<string>]
+
+Default: `['']`
+
+Test files are normally ignored from collecting code coverage. With this option,
+you can overwrite this behavior and include otherwise ignored files in code coverage.
+
+For example, if you have tests in source files named with `.t.js` extension as
+following:
+
+```javascript
+// sum.t.js
+
+export function sum(a,b) {
+  return a + b;
+}
+
+if (process.env.NODE_ENV === 'test') {
+  test('sum', () => {
+    expect(sum(1, 2)).toBe(3);
+  });
+}
+```
+
+You can collect coverage from those files with setting `forceCoverageMatch`.
+```json
+{
+  ...
+  "jest": {
+    "forceCoverageMatch": ["**/*.t.js"]
+  }
+}
+```
+
+
 ### `globals` [object]
 
 Default: `{}`

integration_tests/__tests__/__snapshots__/show_config.test.js.snap

@@ -13,6 +13,7 @@ exports[`--showConfig outputs config info and exits 1`] = `
         \\"/node_modules/\\"
       ],
       \\"detectLeaks\\": false,
+      \\"forceCoverageMatch\\": [],
       \\"globals\\": {},
       \\"haste\\": {
         \\"providesModuleNodeModules\\": []

packages/jest-config/src/defaults.js

@@ -38,6 +38,7 @@ export default ({
   coverageReporters: ['json', 'text', 'lcov', 'clover'],
   detectLeaks: false,
   expand: false,
+  forceCoverageMatch: [],
   globalSetup: null,
   globalTeardown: null,
   globals: {},

packages/jest-config/src/index.js

@@ -130,6 +130,7 @@ const getConfigs = (
       cwd: options.cwd,
       detectLeaks: options.detectLeaks,
       displayName: options.displayName,
+      forceCoverageMatch: options.forceCoverageMatch,
       globals: options.globals,
       haste: options.haste,
       moduleDirectories: options.moduleDirectories,

packages/jest-config/src/normalize.js

@@ -459,6 +459,7 @@ export default function normalize(options: InitialOptions, argv: Argv) {
       case 'expand':
       case 'globals':
       case 'findRelatedTests':
+      case 'forceCoverageMatch':
       case 'forceExit':
       case 'listTests':
       case 'logHeapUsage':

packages/jest-config/src/valid_config.js

@@ -37,6 +37,7 @@ export default ({
   },
   displayName: 'project-name',
   expand: false,
+  forceCoverageMatch: ['**/*.t.js'],
   forceExit: false,
   globalSetup: 'setup.js',
   globalTeardown: 'teardown.js',

packages/jest-runtime/src/__tests__/should_instrument.test.js

@@ -0,0 +1,151 @@
+/**
+ * Copyright (c) 2014-present, Facebook, Inc. All rights reserved.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ */
+
+import shouldInstrument from '../should_instrument';
+
+describe('should_instrument', () => {
+  const defaultFilename = 'source_file.test.js';
+  const defaultOptions = {
+    collectCoverage: true,
+  };
+  const defaultConfig = {
+    rootDir: '/',
+  };
+
+  describe('should return true', () => {
+    const testShouldInstrument = (
+      filename = defaultFilename,
+      options = defaultOptions,
+      config = defaultConfig,
+    ) => {
+      const result = shouldInstrument(filename, options, config);
+      expect(result).toBe(true);
+    };
+
+    it('when testRegex provided and file is not a test file', () => {
+      testShouldInstrument('source_file.js', defaultOptions, {
+        testRegex: '.*\\.(test)\\.(js)$',
+      });
+    });
+
+    it('when testMatch is provided and file is not a test file', () => {
+      testShouldInstrument('source_file.js', defaultOptions, {
+        testMatch: ['**/?(*.)(test).js'],
+      });
+    });
+
+    it('should return true when file is in collectCoverageOnlyFrom when provided', () => {
+      testShouldInstrument(
+        'collect/only/from/here.js',
+
+        {
+          collectCoverage: true,
+          collectCoverageOnlyFrom: {'collect/only/from/here.js': true},
+        },
+        defaultConfig,
+      );
+    });
+
+    it('should return true when filename matches collectCoverageFrom', () => {
+      testShouldInstrument(
+        'do/collect/coverage.js',
+        {
+          collectCoverage: true,
+          collectCoverageFrom: ['!**/dont/**/*.js', '**/do/**/*.js'],
+        },
+        defaultConfig,
+      );
+    });
+
+    it('should return true if the file is not in coveragePathIgnorePatterns', () => {
+      testShouldInstrument('do/collect/coverage.js', defaultOptions, {
+        coveragePathIgnorePatterns: ['dont'],
+        rootDir: '/',
+      });
+    });
+
+    it('should return true if file is a testfile but forceCoverageMatch is set', () => {
+      testShouldInstrument('do/collect/sum.coverage.test.js', defaultOptions, {
+        forceCoverageMatch: ['**/*.(coverage).(test).js'],
+        rootDir: '/',
+        testRegex: '.*\\.(test)\\.(js)$',
+      });
+    });
+  });
+
+  describe('should return false', () => {
+    const testShouldInstrument = (
+      filename = defaultFilename,
+      options = defaultOptions,
+      config = defaultConfig,
+    ) => {
+      const result = shouldInstrument(filename, options, config);
+      expect(result).toBe(false);
+    };
+
+    it('if collectCoverage is falsy', () => {
+      testShouldInstrument(
+        'source_file.js',
+        {
+          collectCoverage: false,
+        },
+        defaultConfig,
+      );
+    });
+
+    it('when testRegex provided and filename is a test file', () => {
+      testShouldInstrument(defaultFilename, defaultOptions, {
+        testRegex: '.*\\.(test)\\.(js)$',
+      });
+    });
+
+    it('when testMatch is provided and file is a test file', () => {
+      testShouldInstrument(defaultFilename, defaultOptions, {
+        testMatch: ['**/?(*.)(test).js'],
+      });
+    });
+
+    it('when file is not in collectCoverageOnlyFrom when provided', () => {
+      testShouldInstrument(
+        'source_file.js',
+        {
+          collectCoverage: true,
+          collectCoverageOnlyFrom: {'collect/only/from/here.js': true},
+        },
+        defaultConfig,
+      );
+    });
+
+    it('when filename does not match collectCoverageFrom', () => {
+      testShouldInstrument(
+        'dont/collect/coverage.js',
+        {
+          collectCoverage: true,
+          collectCoverageFrom: ['!**/dont/**/*.js', '**/do/**/*.js'],
+        },
+        defaultConfig,
+      );
+    });
+
+    it('if the file is in coveragePathIgnorePatterns', () => {
+      testShouldInstrument('dont/collect/coverage.js', defaultOptions, {
+        coveragePathIgnorePatterns: ['dont'],
+        rootDir: '/',
+      });
+    });
+
+    it('if file is in mock patterns', () => {
+      const filename =
+        process.platform === 'win32'
+          ? 'dont\\__mocks__\\collect\\coverage.js'
+          : 'dont/__mocks__/collect/coverage.js';
+
+      testShouldInstrument(filename, defaultOptions, defaultConfig);
+    });
+  });
+});

packages/jest-runtime/src/should_instrument.js

@@ -27,6 +27,14 @@ export default function shouldInstrument(
     return false;
   }
 
+  if (
+    config.forceCoverageMatch &&
+    config.forceCoverageMatch.length &&
+    micromatch.any(filename, config.forceCoverageMatch)
+  ) {
+    return true;
+  }
+
   if (config.testRegex && filename.match(config.testRegex)) {
     return false;
   }

test_utils.js

@@ -70,6 +70,7 @@ const DEFAULT_PROJECT_CONFIG: ProjectConfig = {
   cwd: '/test_root_dir/',
   detectLeaks: false,
   displayName: undefined,
+  forceCoverageMatch: [],
   globals: {},
   haste: {
     providesModuleNodeModules: [],

types/Config.js

@@ -31,6 +31,7 @@ export type DefaultOptions = {|
   coveragePathIgnorePatterns: Array<string>,
   coverageReporters: Array<string>,
   expand: boolean,
+  forceCoverageMatch: Array<Glob>,
   globals: ConfigGlobals,
   globalSetup: ?string,
   globalTeardown: ?string,
@@ -86,6 +87,7 @@ export type InitialOptions = {
   displayName?: string,
   expand?: boolean,
   findRelatedTests?: boolean,
+  forceCoverageMatch?: Array<Glob>,
   forceExit?: boolean,
   json?: boolean,
   globals?: ConfigGlobals,
@@ -212,6 +214,7 @@ export type ProjectConfig = {|
   cwd: Path,
   detectLeaks: boolean,
   displayName: ?string,
+  forceCoverageMatch: Array<Glob>,
   globals: ConfigGlobals,
   haste: HasteConfig,
   moduleDirectories: Array<string>,