feat: add support for v8 code coverage

TestUtils.ts

@@ -59,6 +59,7 @@ const DEFAULT_GLOBAL_CONFIG: Config.GlobalConfig = {
   testTimeout: 5000,
   updateSnapshot: 'none',
   useStderr: false,
+  v8Coverage: false,
   verbose: false,
   watch: false,
   watchAll: false,

e2e/__tests__/__snapshots__/showConfig.test.ts.snap

@@ -120,6 +120,7 @@ exports[`--showConfig outputs config info and exits 1`] = `
     "testSequencer": "<<REPLACED_JEST_PACKAGES_DIR>>/jest-test-sequencer/build/index.js",
     "updateSnapshot": "all",
     "useStderr": false,
+    "v8Coverage": false,
     "verbose": null,
     "watch": false,
     "watchman": true

e2e/__tests__/v8Coverage.test.ts

@@ -0,0 +1,21 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates. 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 path from 'path';
+import runJest from '../runJest';
+
+const DIR = path.resolve(__dirname, '../v8-coverage');
+
+test('does not explode on missing sourcemap', () => {
+  const sourcemapDir = path.join(DIR, 'no-sourcemap');
+  const {stderr, status} = runJest(sourcemapDir, ['--v8-coverage'], {
+    stripAnsi: true,
+  });
+
+  expect(stderr).not.toContain('no such file or directory');
+  expect(status).toBe(0);
+});

e2e/v8-coverage/no-sourcemap/Thing.js

@@ -0,0 +1,3 @@
+require('./x.css');
+
+module.exports = 42;

e2e/v8-coverage/no-sourcemap/__tests__/Thing.test.js

@@ -0,0 +1,4 @@
+const Thing = require('../Thing');
+
+console.log(Thing);
+test.todo('whatever');

e2e/v8-coverage/no-sourcemap/cssTransform.js

@@ -0,0 +1,4 @@
+module.exports = {
+  getCacheKey: () => 'cssTransform',
+  process: () => 'module.exports = {};',
+};

e2e/v8-coverage/no-sourcemap/package.json

@@ -0,0 +1,10 @@
+{
+  "name": "no-sourcemap",
+  "version": "1.0.0",
+  "jest": {
+    "transform": {
+      "^.+\\.[jt]sx?$": "babel-jest",
+      "^.+\\.css$": "<rootDir>/cssTransform.js"
+    }
+  }
+}

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

@@ -17,6 +17,13 @@ export const check = (argv: Config.Argv) => {
     );
   }
 
+  if (argv.collectCoverage && argv.v8Coverage) {
+    throw new Error(
+      'Both --coverage and --v8Coverage were specified, but these two ' +
+        'options do not make sense together. Which is it?',
+    );
+  }
+
   for (const key of [
     'onlyChanged',
     'lastCommit',
@@ -681,6 +688,11 @@ export const options = {
       'Display individual test results with the test suite hierarchy.',
     type: 'boolean' as 'boolean',
   },
+  v8Coverage: {
+    default: false,
+    description: 'Collect coverage using V8 instrumentation',
+    type: 'boolean' as 'boolean',
+  },
   version: {
     alias: 'v',
     default: undefined,

packages/jest-config/src/Defaults.ts

@@ -78,6 +78,7 @@ const defaultOptions: Config.DefaultOptions = {
   transform: null,
   transformIgnorePatterns: [NODE_MODULES_REGEXP],
   useStderr: false,
+  v8Coverage: false,
   verbose: null,
   watch: false,
   watchPathIgnorePatterns: [],

packages/jest-config/src/ValidConfig.ts

@@ -124,6 +124,7 @@ const initialOptions: Config.InitialOptions = {
   unmockedModulePathPatterns: ['mock'],
   updateSnapshot: true,
   useStderr: false,
+  v8Coverage: false,
   verbose: false,
   watch: false,
   watchPathIgnorePatterns: ['<rootDir>/e2e/'],

packages/jest-config/src/index.ts

@@ -152,6 +152,7 @@ const groupOptions = (
     testTimeout: options.testTimeout,
     updateSnapshot: options.updateSnapshot,
     useStderr: options.useStderr,
+    v8Coverage: options.v8Coverage,
     verbose: options.verbose,
     watch: options.watch,
     watchAll: options.watchAll,

packages/jest-config/src/normalize.ts

@@ -849,6 +849,7 @@ export default function normalize(
       case 'timers':
       case 'useStderr':
       case 'verbose':
+      case 'v8Coverage':
       case 'watch':
       case 'watchAll':
       case 'watchman':
@@ -957,7 +958,10 @@ export default function normalize(
   // Is transformed to: `--findRelatedTests '/rootDir/file1.js' --coverage --collectCoverageFrom 'file1.js'`
   // where arguments to `--collectCoverageFrom` should be globs (or relative
   // paths to the rootDir)
-  if (newOptions.collectCoverage && argv.findRelatedTests) {
+  if (
+    (newOptions.collectCoverage || newOptions.v8Coverage) &&
+    argv.findRelatedTests
+  ) {
     let collectCoverageFrom = argv._.map(filename => {
       filename = replaceRootDirInPath(options.rootDir, filename);
       return path.isAbsolute(filename)
@@ -983,6 +987,13 @@ export default function normalize(
     newOptions.collectCoverageFrom = collectCoverageFrom;
   }
 
+  if (newOptions.collectCoverage && newOptions.v8Coverage) {
+    throw createConfigError(
+      `  Configuration options ${chalk.bold('collectCoverage')} and` +
+        ` ${chalk.bold('v8Coverage')} cannot be used together.`,
+    );
+  }
+
   return {
     hasDeprecationWarnings,
     options: newOptions,

packages/jest-core/src/TestScheduler.ts

@@ -258,14 +258,15 @@ export default class TestScheduler {
   }
 
   private _setupReporters() {
-    const {collectCoverage, notify, reporters} = this._globalConfig;
+    const {collectCoverage, notify, reporters, v8Coverage} = this._globalConfig;
     const isDefault = this._shouldAddDefaultReporters(reporters);
+    const willCollectCoverage = collectCoverage || v8Coverage;
 
     if (isDefault) {
-      this._setupDefaultReporters(collectCoverage);
+      this._setupDefaultReporters(willCollectCoverage);
     }
 
-    if (!isDefault && collectCoverage) {
+    if (!isDefault && willCollectCoverage) {
       this.addReporter(
         new CoverageReporter(this._globalConfig, {
           changedFiles: this._context && this._context.changedFiles,

packages/jest-coverage/.npmignore

@@ -0,0 +1,3 @@
+**/__mocks__/**
+**/__tests__/**
+src

packages/jest-coverage/package.json

@@ -0,0 +1,22 @@
+{
+  "name": "@jest/coverage",
+  "version": "24.9.0",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/facebook/jest.git",
+    "directory": "packages/jest-coverage"
+  },
+  "license": "MIT",
+  "main": "build/index.js",
+  "types": "build/index.d.ts",
+  "devDependencies": {
+    "@types/node": "*"
+  },
+  "engines": {
+    "node": ">= 8"
+  },
+  "publishConfig": {
+    "access": "public"
+  },
+  "gitHead": "0efb1d7809cb96ae87a7601e7802f1dab3774280"
+}

packages/jest-coverage/src/index.ts

@@ -0,0 +1,76 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates. 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 {Profiler, Session} from 'inspector';
+
+export type V8Coverage = ReadonlyArray<Profiler.ScriptCoverage>;
+
+export default class CoverageInstrumenter {
+  private readonly session = new Session();
+
+  async startInstrumenting() {
+    this.session.connect();
+
+    await new Promise((resolve, reject) => {
+      this.session.post('Profiler.enable', err => {
+        if (err) {
+          reject(err);
+        } else {
+          resolve();
+        }
+      });
+    });
+
+    await new Promise((resolve, reject) => {
+      this.session.post(
+        'Profiler.startPreciseCoverage',
+        {callCount: true, detailed: true},
+        err => {
+          if (err) {
+            reject(err);
+          } else {
+            resolve();
+          }
+        },
+      );
+    });
+  }
+
+  async stopInstrumenting(): Promise<V8Coverage> {
+    const preciseCoverage = await new Promise<V8Coverage>((resolve, reject) => {
+      this.session.post('Profiler.takePreciseCoverage', (err, res) => {
+        if (err) {
+          reject(err);
+        } else {
+          resolve(res.result);
+        }
+      });
+    });
+
+    await new Promise((resolve, reject) => {
+      this.session.post('Profiler.stopPreciseCoverage', err => {
+        if (err) {
+          reject(err);
+        } else {
+          resolve();
+        }
+      });
+    });
+
+    await new Promise((resolve, reject) => {
+      this.session.post('Profiler.disable', err => {
+        if (err) {
+          reject(err);
+        } else {
+          resolve();
+        }
+      });
+    });
+
+    return preciseCoverage;
+  }
+}

packages/jest-coverage/tsconfig.json

@@ -0,0 +1,7 @@
+{
+  "extends": "../../tsconfig.json",
+  "compilerOptions": {
+    "rootDir": "src",
+    "outDir": "build"
+  }
+}

packages/jest-reporters/src/coverage_reporter.ts

@@ -40,15 +40,15 @@ export default class CoverageReporter extends BaseReporter {
     this._options = options || {};
   }
 
-  onTestResult(
-    _test: Test,
-    testResult: TestResult,
-    _aggregatedResults: AggregatedResult,
-  ) {
+  onTestResult(_test: Test, testResult: TestResult) {
     if (testResult.coverage) {
       this._coverageMap.merge(testResult.coverage);
     }
 
+    if (this._globalConfig.v8Coverage) {
+      return;
+    }
+
     const sourceMaps = testResult.sourceMaps;
     if (sourceMaps) {
       Object.keys(sourceMaps).forEach(sourcePath => {
@@ -76,7 +76,7 @@ export default class CoverageReporter extends BaseReporter {
     contexts: Set<Context>,
     aggregatedResults: AggregatedResult,
   ) {
-    await this._addUntestedFiles(this._globalConfig, contexts);
+    await this._addUntestedFiles(contexts);
     const {map, sourceFinder} = this._sourceMapStore.transformCoverage(
       this._coverageMap,
     );
@@ -93,9 +93,14 @@ export default class CoverageReporter extends BaseReporter {
       }
 
       const tree = istanbulReport.summarizers.pkg(map);
-      coverageReporters.forEach(reporter => {
-        tree.visit(istanbulReports.create(reporter, {}), reportContext);
-      });
+      try {
+        coverageReporters.forEach(reporter => {
+          tree.visit(istanbulReports.create(reporter, {}), reportContext);
+        });
+      } catch (e) {
+        debugger;
+        throw e;
+      }
       aggregatedResults.coverageMap = map;
     } catch (e) {
       console.error(
@@ -110,20 +115,20 @@ export default class CoverageReporter extends BaseReporter {
     this._checkThreshold(this._globalConfig, map);
   }
 
-  private async _addUntestedFiles(
-    globalConfig: Config.GlobalConfig,
-    contexts: Set<Context>,
-  ): Promise<void> {
+  private async _addUntestedFiles(contexts: Set<Context>): Promise<void> {
     const files: Array<{config: Config.ProjectConfig; path: string}> = [];
 
     contexts.forEach(context => {
       const config = context.config;
       if (
-        globalConfig.collectCoverageFrom &&
-        globalConfig.collectCoverageFrom.length
+        this._globalConfig.collectCoverageFrom &&
+        this._globalConfig.collectCoverageFrom.length
       ) {
         context.hasteFS
-          .matchFilesWithGlob(globalConfig.collectCoverageFrom, config.rootDir)
+          .matchFilesWithGlob(
+            this._globalConfig.collectCoverageFrom,
+            config.rootDir,
+          )
           .forEach(filePath =>
             files.push({
               config,
@@ -163,7 +168,7 @@ export default class CoverageReporter extends BaseReporter {
         try {
           const result = await worker.worker({
             config,
-            globalConfig,
+            globalConfig: this._globalConfig,
             options: {
               ...this._options,
               changedFiles:

packages/jest-reporters/src/generateEmptyCoverage.ts

@@ -27,6 +27,7 @@ export default function(
     collectCoverage: globalConfig.collectCoverage,
     collectCoverageFrom: globalConfig.collectCoverageFrom,
     collectCoverageOnlyFrom: globalConfig.collectCoverageOnlyFrom,
+    v8Coverage: globalConfig.v8Coverage,
   };
   let coverageWorkerResult: CoverageWorkerResult | null = null;
   if (shouldInstrument(filename, coverageOptions, config)) {