fix: serialize changedFiles passed to workers

CHANGELOG.md

@@ -7,6 +7,7 @@
 - `[expect]` Compare DOM nodes even if there are multiple Node classes ([#8064](https://github.com/facebook/jest/pull/8064))
 - `[jest-worker]` `worker.getStdout()` can return `null` ([#8083](https://github.com/facebook/jest/pull/8083))
 - `[jest-worker]` Re-attach stdout and stderr from new processes/threads created after retries ([#8087](https://github.com/facebook/jest/pull/8087))
+- `[jest-reporters/jest-runner]` Serialize `changedFiles` passed to workers ([#8090](https://github.com/facebook/jest/pull/8090))
 
 ### Chore & Maintenance
 

e2e/__tests__/onlyChanged.test.ts

@@ -153,12 +153,38 @@ test('do not pickup non-tested files when reporting coverage on only changed fil
     'package.json': JSON.stringify({name: 'new name'}),
   });
 
-  const {stderr, stdout} = runJest(DIR, ['-o', '--coverage']);
-
+  const {stderr, stdout, status} = runJest(DIR, ['-o', '--coverage']);
   expect(stderr).toEqual(
     expect.not.stringContaining('Failed to collect coverage from'),
   );
   expect(stdout).toEqual(expect.not.stringContaining('package.json'));
+  expect(status).toBe(0);
+});
+
+test('collect test coverage when using onlyChanged', () => {
+  writeFiles(DIR, {
+    'a.js': 'module.exports = {}',
+    'b.test.js': 'module.exports = {}',
+    'package.json': JSON.stringify({
+      jest: {collectCoverageFrom: ['a.js']},
+      name: 'original name',
+    }),
+  });
+
+  run(`${GIT} init`, DIR);
+  run(`${GIT} add .`, DIR);
+  run(`${GIT} commit --no-gpg-sign -m "first"`, DIR);
+  run(`${GIT} checkout -b new-branch`, DIR);
+
+  writeFiles(DIR, {
+    'b.test.js': 'it("passes", () => {expect(1).toBe(1)})',
+  });
+
+  const {stderr, status} = runJest(DIR, ['-o', '--coverage']);
+  expect(stderr).toEqual(
+    expect.not.stringContaining('Failed to collect coverage from'),
+  );
+  expect(status).toBe(0);
 });
 
 test('onlyChanged in config is overwritten by --all or testPathPattern', () => {

packages/jest-reporters/src/coverage_reporter.ts

@@ -170,7 +170,12 @@ export default class CoverageReporter extends BaseReporter {
           const result = await worker.worker({
             config,
             globalConfig,
-            options: this._options,
+            options: {
+              ...this._options,
+              changedFiles:
+                this._options.changedFiles &&
+                Array.from(this._options.changedFiles),
+            },
             path: filename,
           });
 

packages/jest-reporters/src/coverage_worker.ts

@@ -8,7 +8,7 @@
 import fs from 'fs';
 import {Config} from '@jest/types';
 import exit from 'exit';
-import {CoverageReporterOptions} from './types';
+import {CoverageReporterSerializedOptions} from './types';
 
 import generateEmptyCoverage, {
   CoverageWorkerResult,
@@ -18,7 +18,7 @@ export type CoverageWorkerData = {
   globalConfig: Config.GlobalConfig;
   config: Config.ProjectConfig;
   path: Config.Path;
-  options?: CoverageReporterOptions;
+  options?: CoverageReporterSerializedOptions;
 };
 
 export {CoverageWorkerResult};
@@ -40,6 +40,6 @@ export function worker({
     path,
     globalConfig,
     config,
-    options && options.changedFiles,
+    options && options.changedFiles && new Set(options.changedFiles),
   );
 }

packages/jest-reporters/src/types.ts

@@ -41,6 +41,10 @@ export type CoverageReporterOptions = {
   changedFiles?: Set<Config.Path>;
 };
 
+export type CoverageReporterSerializedOptions = {
+  changedFiles?: Array<Config.Path>;
+};
+
 export type OnTestStart = (test: Test) => Promise<void>;
 export type OnTestFailure = (
   test: Test,

packages/jest-runner/src/index.ts

@@ -127,7 +127,12 @@ class TestRunner {
 
         return worker.worker({
           config: test.context.config,
-          context: this._context,
+          context: {
+            ...this._context,
+            changedFiles:
+              this._context.changedFiles &&
+              Array.from(this._context.changedFiles),
+          },
           globalConfig: this._globalConfig,
           path: test.path,
           serializableModuleMap: watcher.isWatchMode()

packages/jest-runner/src/testWorker.ts

@@ -12,15 +12,15 @@ import HasteMap, {SerializableModuleMap, ModuleMap} from 'jest-haste-map';
 import exit from 'exit';
 import {separateMessageFromStack} from 'jest-message-util';
 import Runtime from 'jest-runtime';
-import {ErrorWithCode, TestRunnerContext} from './types';
+import {ErrorWithCode, TestRunnerSerializedContext} from './types';
 import runTest from './runTest';
 
 type WorkerData = {
   config: Config.ProjectConfig;
   globalConfig: Config.GlobalConfig;
   path: Config.Path;
   serializableModuleMap: SerializableModuleMap | null;
-  context?: TestRunnerContext;
+  context?: TestRunnerSerializedContext;
 };
 
 // Make sure uncaught errors are logged before we exit.
@@ -86,7 +86,10 @@ export async function worker({
       globalConfig,
       config,
       getResolver(config, moduleMap),
-      context,
+      context && {
+        ...context,
+        changedFiles: context.changedFiles && new Set(context.changedFiles),
+      },
     );
   } catch (error) {
     throw formatError(error);

packages/jest-runner/src/types.ts

@@ -53,6 +53,10 @@ export type TestRunnerContext = {
   changedFiles?: Set<Config.Path>;
 };
 
+export type TestRunnerSerializedContext = {
+  changedFiles?: Array<Config.Path>;
+};
+
 // TODO: Should live in `@jest/core` or `jest-watcher`
 export type WatcherState = {
   interrupted: boolean;

packages/test-utils/package.json

@@ -4,5 +4,5 @@
   "private": true,
   "license": "MIT",
   "main": "build/index.js",
-  "types": "src/index.d.ts"
+  "types": "build/index.d.ts"
 }