Generating coverage for files passed in --findRelatedTests, --onlyChanged and --watch scenarios

CHANGELOG.md

@@ -2,6 +2,9 @@
 
 ### Features
 
+* `[jest-cli]` Add support for using `--coverage` in combination with watch
+  mode, `--onlyChanged`, `--findRelatedTests` and more
+  ([#5601](https://github.com/facebook/jest/pull/5601))
 * `[jest-jasmine2]` Adds error throwing and descriptive errors to `it`/ `test`
   for invalid arguments. `[jest-circus]` Adds error throwing and descriptive
   errors to `it`/ `test` for invalid arguments

docs/CLI.md

@@ -189,7 +189,9 @@ Alias: `-e`. Use this flag to show full diffs and errors instead of a patch.
 
 Find and run the tests that cover a space separated list of source files that
 were passed in as arguments. Useful for pre-commit hook integration to run the
-minimal amount of tests necessary.
+minimal amount of tests necessary. Can be used together with `--coverage` to
+include a test coverage for the source files, no duplicate
+`--collectCoverageFrom` arguments needed.
 
 ### `--forceExit`
 

integration-tests/Utils.js

@@ -166,7 +166,6 @@ const cleanupStackTrace = (output: string) => {
 
 module.exports = {
   cleanup,
-  cleanupStackTrace,
   copyDir,
   createEmptyPackage,
   extractSummary,

integration-tests/__tests__/__snapshots__/find_related_files.test.js.snap

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

integration-tests/__tests__/find_related_files.test.js

@@ -13,7 +13,7 @@ import runJest from '../runJest';
 import os from 'os';
 import path from 'path';
 
-const {cleanup, writeFiles} = require('../Utils');
+const {cleanup, writeFiles, extractSummary} = require('../Utils');
 
 const SkipOnWindows = require('../../scripts/SkipOnWindows');
 const DIR = path.resolve(os.tmpdir(), 'find_related_tests_test');
@@ -23,23 +23,74 @@ SkipOnWindows.suite();
 beforeEach(() => cleanup(DIR));
 afterEach(() => cleanup(DIR));
 
-test('runs tests related to filename', () => {
-  writeFiles(DIR, {
-    '.watchmanconfig': '',
-    '__tests__/test.test.js': `
+describe('--findRelatedTests flag', () => {
+  test('runs tests related to filename', () => {
+    writeFiles(DIR, {
+      '.watchmanconfig': '',
+      '__tests__/test.test.js': `
       const a = require('../a');
       test('a', () => {});
     `,
-    'a.js': 'module.exports = {};',
-    'package.json': JSON.stringify({jest: {testEnvironment: 'node'}}),
+      'a.js': 'module.exports = {};',
+      'package.json': JSON.stringify({jest: {testEnvironment: 'node'}}),
+    });
+
+    const {stdout} = runJest(DIR, ['a.js']);
+    expect(stdout).toMatch('');
+
+    const {stderr} = runJest(DIR, ['--findRelatedTests', 'a.js']);
+    expect(stderr).toMatch('PASS __tests__/test.test.js');
+
+    const summaryMsg = 'Ran all test suites related to files matching /a.js/i.';
+    expect(stderr).toMatch(summaryMsg);
   });
 
-  const {stdout} = runJest(DIR, ['a.js']);
-  expect(stdout).toMatch('');
+  test('generates coverage report for filename', () => {
+    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: {collectCoverage: true, testEnvironment: 'node'},
+      }),
+    });
+
+    let stdout;
+    let stderr;
 
-  const {stderr} = runJest(DIR, ['--findRelatedTests', 'a.js']);
-  expect(stderr).toMatch('PASS __tests__/test.test.js');
+    ({stdout, stderr} = runJest(DIR));
+    let summary;
+    let rest;
+    ({summary, rest} = extractSummary(stderr));
+    expect(summary).toMatchSnapshot();
+    expect(
+      rest
+        .split('\n')
+        .map(s => s.trim())
+        .sort()
+        .join('\n'),
+    ).toMatchSnapshot();
 
-  const summaryMsg = 'Ran all test suites related to files matching /a.js/i.';
-  expect(stderr).toMatch(summaryMsg);
+    // both a.js and b.js should be in the coverage
+    expect(stdout).toMatchSnapshot();
+
+    ({stdout, stderr} = runJest(DIR, ['--findRelatedTests', '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__/only_changed.test.js

@@ -73,6 +73,51 @@ test('run only changed files', () => {
   expect(stderr).toMatch(/PASS __tests__(\/|\\)file3.test.js/);
 });
 
+test('report test coverage for only changed files', () => {
+  writeFiles(DIR, {
+    '__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: {
+        collectCoverage: true,
+        coverageReporters: ['text'],
+        testEnvironment: 'node',
+      },
+    }),
+  });
+
+  run(`${GIT} init`, DIR);
+  run(`${GIT} add .`, DIR);
+  run(`${GIT} commit -m "first"`, DIR);
+
+  writeFiles(DIR, {
+    'a.js': 'module.exports = {modified: true}',
+  });
+
+  let stdout;
+
+  ({stdout} = runJest(DIR));
+
+  // both a.js and b.js should be in the coverage
+  expect(stdout).toMatch('a.js');
+  expect(stdout).toMatch('b.js');
+
+  ({stdout} = runJest(DIR, ['-o']));
+
+  // coverage should be collected only for a.js
+  expect(stdout).toMatch('a.js');
+  expect(stdout).not.toMatch('b.js');
+});
+
 test('onlyChanged in config is overwritten by --all or testPathPattern', () => {
   writeFiles(DIR, {
     '.watchmanconfig': '',

packages/jest-cli/src/__tests__/run_jest_with_coverage.test.js

@@ -0,0 +1,112 @@
+import runJest from '../run_jest';
+
+jest.mock('jest-util');
+
+jest.mock(
+  '../test_scheduler',
+  () =>
+    class {
+      constructor(globalConfig) {
+        this._globalConfig = globalConfig;
+      }
+
+      scheduleTests() {
+        return {_globalConfig: this._globalConfig};
+      }
+    },
+);
+
+jest.mock(
+  '../test_sequencer',
+  () =>
+    class {
+      sort(allTests) {
+        return allTests;
+      }
+      cacheResults() {}
+    },
+);
+
+jest.mock(
+  '../search_source',
+  () =>
+    class {
+      constructor(context) {
+        this._context = context;
+      }
+
+      async getTestPaths(globalConfig, changedFilesPromise) {
+        const {files} = await changedFilesPromise;
+        const paths = files.filter(path => path.match(/__tests__/));
+
+        return {
+          collectCoverageFrom: files.filter(path => !path.match(/__tests__/)),
+          tests: paths.map(path => ({
+            context: this._context,
+            duration: null,
+            path,
+          })),
+        };
+      }
+    },
+);
+
+const config = {roots: [], testPathIgnorePatterns: [], testRegex: ''};
+let globalConfig;
+const defaults = {
+  changedFilesPromise: Promise.resolve({
+    files: ['foo.js', '__tests__/foo-test.js', 'dont/cover.js'],
+  }),
+  contexts: [{config}],
+  onComplete: runResults => (globalConfig = runResults._globalConfig),
+  outputStream: {},
+  startRun: {},
+  testWatcher: {isInterrupted: () => false},
+};
+
+describe('collectCoverageFrom patterns', () => {
+  it('should apply collectCoverageFrom patterns coming from SearchSource', async () => {
+    expect.assertions(1);
+
+    await runJest(
+      Object.assign({}, defaults, {
+        globalConfig: {
+          rootDir: '',
+        },
+      }),
+    );
+    expect(globalConfig.collectCoverageFrom).toEqual([
+      'foo.js',
+      'dont/cover.js',
+    ]);
+  });
+
+  it('excludes coverage from files outside the global collectCoverageFrom config', async () => {
+    expect.assertions(1);
+
+    await runJest(
+      Object.assign({}, defaults, {
+        globalConfig: {
+          collectCoverageFrom: ['**/dont/*.js'],
+          rootDir: '',
+        },
+      }),
+    );
+    expect(globalConfig.collectCoverageFrom).toEqual(['dont/cover.js']);
+  });
+
+  it('respects coveragePathIgnorePatterns', async () => {
+    expect.assertions(1);
+
+    await runJest(
+      Object.assign({}, defaults, {
+        globalConfig: {
+          collectCoverageFrom: ['**/*.js'],
+          coveragePathIgnorePatterns: ['dont'],
+          rootDir: '',
+        },
+      }),
+    );
+    expect(globalConfig.collectCoverageFrom).toEqual(['foo.js']);
+  });
+});