changed files eager loading

packages/jest-changed-files/src/git.js

@@ -9,7 +9,7 @@
  */
 
 import type {Path} from 'types/Config';
-import type {Options, SCMAdapter} from '../types';
+import type {Options, SCMAdapter} from 'types/ChangedFiles';
 
 import path from 'path';
 import childProcess from 'child_process';

packages/jest-changed-files/src/hg.js

@@ -9,7 +9,7 @@
  */
 
 import type {Path} from 'types/Config';
-import type {Options, SCMAdapter} from '../types';
+import type {Options, SCMAdapter} from 'types/ChangedFiles';
 
 import path from 'path';
 import childProcess from 'child_process';

packages/jest-changed-files/src/index.js

@@ -9,7 +9,7 @@
  */
 
 import type {Path} from 'types/Config';
-import type {Options, Repos} from '../types';
+import type {ChangedFilesPromise, Options, Repos} from 'types/ChangedFiles';
 
 import git from './git';
 import hg from './hg';
@@ -25,8 +25,9 @@ const findHgRoot = dir => mutex(() => hg.getRoot(dir));
 const getChangedFilesForRoots = async (
   roots: Array<Path>,
   options: Options,
-): Promise<{changedFiles: Set<Path>, repos: Repos}> => {
+): ChangedFilesPromise => {
   const repos = await findRepos(roots);
+
   const gitPromises = Array.from(repos.git).map(repo =>
     git.findChangedFiles(repo, options),
   );

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

@@ -65,6 +65,7 @@ describe('Watch mode flows', () => {
       pipe,
       new TestWatcher({isWatchMode: true}),
       expect.any(Function),
+      undefined,
       expect.any(Function),
     );
   });
@@ -82,6 +83,7 @@ describe('Watch mode flows', () => {
       pipe,
       new TestWatcher({isWatchMode: true}),
       expect.any(Function),
+      undefined,
       expect.any(Function),
     );
   });
@@ -95,6 +97,7 @@ describe('Watch mode flows', () => {
       pipe,
       new TestWatcher({isWatchMode: true}),
       expect.any(Function),
+      undefined,
       expect.any(Function),
     );
     expect(pipe.write.mock.calls.reverse()[0]).toMatchSnapshot();

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

@@ -23,6 +23,7 @@ import {version as VERSION} from '../../package.json';
 import args from './args';
 import chalk from 'chalk';
 import createContext from '../lib/create_context';
+import getChangedFilesPromise from '../get_changed_files_promise';
 import getJest from './get_jest';
 import getMaxWorkers from '../lib/get_max_workers';
 import handleDeprecationWarnings from '../lib/handle_deprecation_warnings';
@@ -251,6 +252,9 @@ const _run = async (
   argv,
   onComplete,
 ) => {
+  // Queries to hg/git can take a while, so we need to start the process
+  // as soon as possible, so by the time we need the result it's already there.
+  const changedFilesPromise = getChangedFilesPromise(argv, configs);
   const {contexts, hasteMapInstances} = await _buildContextsAndHasteMaps(
     configs,
     globalConfig,
@@ -267,8 +271,16 @@ const _run = async (
         globalConfig,
         outputStream,
         hasteMapInstances,
+        changedFilesPromise,
       )
-    : _runWithoutWatch(globalConfig, contexts, argv, outputStream, onComplete);
+    : _runWithoutWatch(
+        globalConfig,
+        contexts,
+        argv,
+        outputStream,
+        onComplete,
+        changedFilesPromise,
+      );
 };
 
 const _runWatch = async (
@@ -279,6 +291,7 @@ const _runWatch = async (
   globalConfig,
   outputStream,
   hasteMapInstances,
+  changedFilesPromise,
 ) => {
   if (hasDeprecationWarnings) {
     try {
@@ -304,6 +317,7 @@ const _runWithoutWatch = async (
   argv,
   outputStream,
   onComplete,
+  changedFilesPromise,
 ) => {
   const startRun = () => {
     if (!argv.listTests) {
@@ -316,6 +330,7 @@ const _runWithoutWatch = async (
       outputStream,
       new TestWatcher({isWatchMode: false}),
       startRun,
+      changedFilesPromise,
       onComplete,
     );
   };

packages/jest-cli/src/get_changed_files_promise.js

@@ -0,0 +1,31 @@
+/**
+ * Copyright (c) 2014, 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
+ */
+
+import type {Argv} from 'types/Argv';
+import type {ProjectConfig} from 'types/Config';
+import type {ChangedFilesPromise} from 'types/ChangedFiles';
+import {getChangedFilesForRoots} from 'jest-changed-files';
+
+module.exports = (
+  argv: Argv,
+  configs: Array<ProjectConfig>,
+): ?ChangedFilesPromise => {
+  if (argv.onlyChanged) {
+    const allRootsForAllProjects = configs.reduce(
+      (roots, config) => roots.concat(config.roots || []),
+      [],
+    );
+    return getChangedFilesForRoots(allRootsForAllProjects, {
+      lastCommit: argv.lastCommit,
+    });
+  }
+
+  return undefined;
+};

packages/jest-cli/src/lib/get_test_path_pattern.js

@@ -36,7 +36,6 @@ module.exports = (argv: Argv): TestSelectionConfig => {
   if (argv.onlyChanged) {
     return {
       input: '',
-      lastCommit: argv.lastCommit,
       onlyChanged: true,
       watch: argv.watch,
     };

packages/jest-cli/src/run_jest.js

@@ -10,6 +10,7 @@
 
 import type {Argv} from 'types/Argv';
 import type {Context} from 'types/Context';
+import type {ChangedFilesPromise} from 'types/ChangedFiles';
 import type {GlobalConfig} from 'types/Config';
 import type {TestSelectionConfig} from './search_source';
 import type {AggregatedResult} from 'types/TestResult';
@@ -102,19 +103,23 @@ const getNoTestsFoundMessage = (testRunData, pattern) => {
 const getTestPaths = async (
   globalConfig,
   context,
-  pattern,
+  testSelectionConfig,
   argv,
   outputStream,
+  changedFilesPromise,
 ) => {
   const source = new SearchSource(context);
-  let data = await source.getTestPaths(pattern);
+  let data = await source.getTestPaths(
+    testSelectionConfig,
+    changedFilesPromise,
+  );
   if (!data.tests.length) {
-    if (pattern.onlyChanged && data.noSCM) {
+    if (testSelectionConfig.onlyChanged && data.noSCM) {
       if (globalConfig.watch) {
         // Run all the tests
         updateArgv(argv, 'watchAll', {noSCM: true});
-        pattern = getTestPathPattern(argv);
-        data = await source.getTestPaths(pattern);
+        testSelectionConfig = getTestPathPattern(argv);
+        data = await source.getTestPaths(testSelectionConfig);
       } else {
         new Console(outputStream, outputStream).log(
           'Jest can only find uncommitted changed files in a git or hg ' +
@@ -160,6 +165,7 @@ const runJest = async (
   outputStream: stream$Writable | tty$WriteStream,
   testWatcher: TestWatcher,
   startRun: () => *,
+  changedFilesPromise: ?ChangedFilesPromise,
   onComplete: (testResults: AggregatedResult) => any,
   // We use this internaly at FB. Since we run multiple processes and most
   // of them don't match any tests, we don't want to print 'no tests found'
@@ -184,6 +190,7 @@ const runJest = async (
         testSelectionConfig,
         argv,
         outputStream,
+        changedFilesPromise,
       );
       allTests = allTests.concat(matches.tests);
       return {context, matches};

packages/jest-cli/src/search_source.js

@@ -12,11 +12,11 @@ import type {Context} from 'types/Context';
 import type {Glob, Path} from 'types/Config';
 import type {ResolveModuleConfig} from 'types/Resolve';
 import type {Test} from 'types/TestRunner';
+import type {ChangedFilesPromise} from 'types/ChangedFiles';
 
 import path from 'path';
 import micromatch from 'micromatch';
 import DependencyResolver from 'jest-resolve-dependencies';
-import {getChangedFilesForRoots} from 'jest-changed-files';
 import {escapePathForRegex, replacePathSepForRegex} from 'jest-regex-util';
 
 type SearchResult = {|
@@ -28,15 +28,9 @@ type SearchResult = {|
 
 type StrOrRegExpPattern = RegExp | string;
 
-type Options = {|
-  lastCommit?: boolean,
-  withAncestor?: boolean,
-|};
-
 export type TestSelectionConfig = {|
   input?: string,
   findRelatedTests?: boolean,
-  lastCommit?: boolean,
   onlyChanged?: boolean,
   paths?: Array<Path>,
   shouldTreatInputAsPattern?: boolean,
@@ -183,27 +177,28 @@ class SearchSource {
     return {tests: []};
   }
 
-  async findChangedTests(options: Options): Promise<SearchResult> {
-    const {repos, changedFiles} = await getChangedFilesForRoots(
-      this._context.config.roots,
-      options,
-    );
+  async findTestRelatedToChangedFiles(
+    changedFilesPromise: ChangedFilesPromise,
+  ) {
+    const {repos, changedFiles} = await changedFilesPromise;
 
     // no SCM (git/hg/...) is found in any of the roots.
     const noSCM = Object.keys(repos).every(scm => repos[scm].size === 0);
-
     return noSCM
       ? {noSCM: true, tests: []}
       : this.findRelatedTests(changedFiles);
   }
 
-  getTestPaths(
+  async getTestPaths(
     testSelectionConfig: TestSelectionConfig,
+    changedFilesPromise: ?ChangedFilesPromise,
   ): Promise<SearchResult> {
     if (testSelectionConfig.onlyChanged) {
-      return this.findChangedTests({
-        lastCommit: testSelectionConfig.lastCommit,
-      });
+      if (!changedFilesPromise) {
+        throw new Error('This promise must be present when running with -o.');
+      }
+
+      return this.findTestRelatedToChangedFiles(changedFilesPromise);
     } else if (
       testSelectionConfig.findRelatedTests &&
       testSelectionConfig.paths

packages/jest-cli/src/watch.js

@@ -14,6 +14,7 @@ import type {Context} from 'types/Context';
 
 import ansiEscapes from 'ansi-escapes';
 import chalk from 'chalk';
+import getChangedFilesPromise from './get_changed_files_promise';
 import {replacePathSepForRegex} from 'jest-regex-util';
 import HasteMap from 'jest-haste-map';
 import isCI from 'is-ci';
@@ -115,6 +116,8 @@ const watch = (
         testPathPattern: argv.testPathPattern,
       }),
     );
+    const configs = contexts.map(context => context.config);
+    const changedFilesPromise = getChangedFilesPromise(argv, configs);
     return runJest(
       // $FlowFixMe
       globalConfig,
@@ -123,6 +126,7 @@ const watch = (
       pipe,
       testWatcher,
       startRun,
+      changedFilesPromise,
       results => {
         isRunning = false;
         hasSnapshotFailure = !!results.snapshot.failure;

types/ChangedFiles.js

@@ -0,0 +1,28 @@
+/**
+ * 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
+ */
+
+import type {Path} from 'types/Config';
+
+export type Options = {|
+  lastCommit?: boolean,
+  withAncestor?: boolean,
+|};
+
+export type ChangedFiles = Set<Path>;
+export type Repos = {|git: Set<Path>, hg: Set<Path>|};
+export type ChangedFilesPromise = Promise<{|
+  repos: Repos,
+  changedFiles: ChangedFiles,
+|}>;
+
+export type SCMAdapter = {|
+  findChangedFiles: (cwd: Path, options: Options) => Promise<Array<Path>>,
+  getRoot: (cwd: Path) => Promise<?Path>,
+|};