--generateCoverageForFiles

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

@@ -0,0 +1,54 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`--generateCoverageForFiles 1`] = `
+"Test Suites: 2 passed, 2 total
+Tests:       2 passed, 2 total
+Snapshots:   0 total
+Time:        <<REPLACED>>
+Ran all test suites.
+"
+`;
+
+exports[`--generateCoverageForFiles 2`] = `
+"
+
+PASS  __tests__/a.test.js
+PASS  __tests__/b.test.js"
+`;
+
+exports[`--generateCoverageForFiles 3`] = `
+"----------|----------|----------|----------|----------|----------------|
+File      |  % Stmts | % Branch |  % Funcs |  % Lines |Uncovered Lines |
+----------|----------|----------|----------|----------|----------------|
+All files |      100 |      100 |      100 |      100 |                |
+ a.js     |      100 |      100 |      100 |      100 |                |
+ b.js     |      100 |      100 |      100 |      100 |                |
+----------|----------|----------|----------|----------|----------------|
+"
+`;
+
+exports[`--generateCoverageForFiles 4`] = `
+"Test Suites: 1 passed, 1 total
+Tests:       1 passed, 1 total
+Snapshots:   0 total
+Time:        <<REPLACED>>
+Ran all test suites matching /a.js/i.
+"
+`;
+
+exports[`--generateCoverageForFiles 5`] = `
+" PASS  __tests__/a.test.js
+  ✓ a
+
+"
+`;
+
+exports[`--generateCoverageForFiles 6`] = `
+"----------|----------|----------|----------|----------|----------------|
+File      |  % Stmts | % Branch |  % Funcs |  % Lines |Uncovered Lines |
+----------|----------|----------|----------|----------|----------------|
+All files |      100 |      100 |      100 |      100 |                |
+ a.js     |      100 |      100 |      100 |      100 |                |
+----------|----------|----------|----------|----------|----------------|
+"
+`;

integration_tests/__tests__/generate_coverage_for_files.test.js

@@ -0,0 +1,66 @@
+/**
+ * Copyright (c) 2014-present, Facebook, Inc. All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @flow
+ */
+
+'use strict';
+
+const path = require('path');
+const os = require('os');
+const skipOnWindows = require('../../scripts/skip_on_windows');
+const {cleanup, writeFiles, extractSummary} = require('../utils');
+const runJest = require('../runJest');
+
+const DIR = path.resolve(os.tmpdir(), 'generate_coverage_for_files_test');
+
+skipOnWindows.suite();
+
+beforeEach(() => cleanup(DIR));
+afterAll(() => cleanup(DIR));
+
+test('--generateCoverageForFiles', () => {
+  writeFiles(DIR, {
+    '.watchmanconfig': '',
+    '__tests__/a.test.js': `
+      require('../a');
+      require('../b');
+      test('a', () => expect(1).toBe(1));
+    `,
+    '__tests__/b.test.js': `
+      require('../b');
+      test('b', () => expect(1).toBe(1));
+    `,
+    'a.js': 'module.exports = {}',
+    'b.js': 'module.exports = {}',
+    'package.json': JSON.stringify({jest: {testEnvironment: 'node'}}),
+  });
+
+  let stdout;
+  let stderr;
+
+  ({stdout, stderr} = runJest(DIR, ['--coverage']));
+  let summary;
+  let rest;
+  ({summary, rest} = extractSummary(stderr));
+  expect(summary).toMatchSnapshot();
+  expect(
+    rest.split('\n').map(s => s.trim()).sort().join('\n'),
+  ).toMatchSnapshot();
+  // both a.js and b.js should be in the coverage
+  expect(stdout).toMatchSnapshot();
+
+  ({stdout, stderr} = runJest(DIR, ['--generateCoverageForFiles', 'a.js']));
+
+  ({summary, rest} = extractSummary(stderr));
+
+  expect(summary).toMatchSnapshot();
+  // should only run a.js
+  expect(rest).toMatchSnapshot();
+  // coverage should be collected only for a.js
+  expect(stdout).toMatchSnapshot();
+});

integration_tests/__tests__/list_tests.test.js

@@ -13,6 +13,7 @@ const runJest = require('../runJest');
 const path = require('path');
 
 const testRootDir = path.resolve(__dirname, '..', '..');
+// $FlowFixMe
 expect.addSnapshotSerializer({
   print: val => val.replace(new RegExp(testRootDir, 'g'), '/MOCK_ABOLUTE_PATH'),
   test: val => typeof val === 'string' && val.includes(testRootDir),

packages/jest-cli/src/cli/args.js

@@ -224,6 +224,12 @@ const options = {
       'adequately cleaned up.',
     type: 'boolean',
   },
+  generateCoverageForFiles: {
+    description:
+      'Run related tests for a list of source files that were passed in as ' +
+      'arguments and collect coverage for them',
+    type: 'boolean',
+  },
   globals: {
     description:
       'A JSON string with map of global variables that need ' +

packages/jest-config/src/normalize.js

@@ -538,6 +538,21 @@ function normalize(options: InitialOptions, argv: Argv) {
       .filter(reporter => reporter !== 'text');
   }
 
+  // generateCoverageForFiles is an alias for
+  // `--findRelatedTests '/rootDir/file1.js' --coverage --collectCoverageFrom 'file1.js'`
+  // where arguments to `--collectCoverageFrom` should be globs (or relative
+  // paths to the rootDir)
+  if (argv.generateCoverageForFiles) {
+    newOptions.findRelatedTests = true;
+    newOptions.collectCoverage = true;
+    newOptions.collectCoverageFrom = argv._.map(filename => {
+      filename = _replaceRootDirInPath(options.rootDir, filename);
+      return path.isAbsolute(filename)
+        ? path.relative(options.rootDir, filename)
+        : filename;
+    });
+  }
+
   return {
     hasDeprecationWarnings,
     options: newOptions,

types/Argv.js

@@ -34,6 +34,7 @@ export type Argv = {|
   expand: boolean,
   findRelatedTests: boolean,
   forceExit: boolean,
+  generateCoverageForFiles: boolean,
   globals: string,
   h: boolean,
   haste: string,