Intercept process.stdout and process.stderr

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 - `[jest-circus, jest-jasmine2]` Include `failureDetails` property in test results ([#9496](https://github.com/facebook/jest/pull/9496))
 - `[jest-each, jest-jasmine, jest-circus]` Add support for .concurrent.each ([#9326](https://github.com/facebook/jest/pull/9326))
+- `[jest-runner]` [**BREAKING**] Intercept `process.stdout` and `process.stderr` in the same way as `console` methods ([#6524](https://github.com/facebook/jest/pull/6524))
 
 ### Fixes
 

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

@@ -23,7 +23,7 @@ PASS __tests__/console.test.js
          |           ^
       15 | 
       16 |   console.error('This is an error message.');
-      17 | });
+      17 | 
 
       at Object.warn (__tests__/console.test.js:14:11)
 
@@ -34,10 +34,28 @@ PASS __tests__/console.test.js
       15 | 
     > 16 |   console.error('This is an error message.');
          |           ^
-      17 | });
-      18 | 
+      17 | 
+      18 |   process.stdout.write('write directly to stdout');
+      19 | 
 
       at Object.error (__tests__/console.test.js:16:11)
+
+    process.stdout.write
+      write directly to stdout
+
+      at Object.write (__tests__/console.test.js:18:18)
+
+    process.stderr.write
+      write directly to stderr
+
+      18 |   process.stdout.write('write directly to stdout');
+      19 | 
+    > 20 |   process.stderr.write('write directly to stderr');
+         |                  ^
+      21 | });
+      22 | 
+
+      at Object.write (__tests__/console.test.js:20:18)
 `;
 
 exports[`console printing 2`] = `
@@ -68,7 +86,7 @@ exports[`console printing with --verbose 1`] = `
          |           ^
       15 | 
       16 |   console.error('This is an error message.');
-      17 | });
+      17 | 
 
       at Object.warn (__tests__/console.test.js:14:11)
 
@@ -79,11 +97,27 @@ exports[`console printing with --verbose 1`] = `
       15 | 
     > 16 |   console.error('This is an error message.');
          |           ^
-      17 | });
-      18 | 
+      17 | 
+      18 |   process.stdout.write('write directly to stdout');
+      19 | 
 
       at Object.error (__tests__/console.test.js:16:11)
 
+  process.stdout.write
+    write directly to stdout
+
+      at Object.write (__tests__/console.test.js:18:18)
+  process.stderr.write
+    write directly to stderr
+
+      18 |   process.stdout.write('write directly to stdout');
+      19 | 
+    > 20 |   process.stderr.write('write directly to stderr');
+         |                  ^
+      21 | });
+      22 | 
+
+      at Object.write (__tests__/console.test.js:20:18)
 `;
 
 exports[`console printing with --verbose 2`] = `
@@ -166,6 +200,14 @@ exports[`respects --noStackTrace 1`] = `
 
       at Object.error (__tests__/console.test.js:16:11)
 
+  process.stdout.write
+    write directly to stdout
+
+      at Object.write (__tests__/console.test.js:18:18)
+  process.stderr.write
+    write directly to stderr
+
+      at Object.write (__tests__/console.test.js:20:18)
 `;
 
 exports[`respects --noStackTrace 2`] = `
@@ -202,6 +244,14 @@ exports[`respects noStackTrace in config 1`] = `
 
       at Object.error (__tests__/console.test.js:16:11)
 
+  process.stdout.write
+    write directly to stdout
+
+      at Object.write (__tests__/console.test.js:18:18)
+  process.stderr.write
+    write directly to stderr
+
+      at Object.write (__tests__/console.test.js:20:18)
 `;
 
 exports[`respects noStackTrace in config 2`] = `

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

@@ -15,6 +15,6 @@ PASS __tests__/console.test.js
       14 | });
       15 | 
 
-      at BufferedConsole.log (../../packages/jest-console/build/BufferedConsole.js:201:10)
+      at BufferedConsole.log (../../packages/jest-console/build/BufferedConsole.js:202:10)
       at log (__tests__/console.test.js:12:13)
 `;

e2e/console/__tests__/console.test.js

@@ -14,4 +14,8 @@ test('works just fine', () => {
   console.warn('This is a warning message.');
 
   console.error('This is an error message.');
+
+  process.stdout.write('write directly to stdout');
+
+  process.stderr.write('write directly to stderr');
 });

packages/jest-console/src/BufferedConsole.ts

@@ -12,6 +12,7 @@ import chalk = require('chalk');
 import {ErrorWithStack, formatTime} from 'jest-util';
 import type {
   ConsoleBuffer,
+  LogApi,
   LogCounters,
   LogMessage,
   LogTimers,
@@ -24,11 +25,10 @@ export default class BufferedConsole extends Console {
   private _timers: LogTimers;
   private _groupDepth: number;
 
-  constructor() {
-    const buffer: ConsoleBuffer = [];
+  constructor(buffer: ConsoleBuffer) {
     super({
       write: (message: string) => {
-        BufferedConsole.write(buffer, 'log', message, null);
+        BufferedConsole.write(buffer, 'log', message, null, 'console');
 
         return true;
       },
@@ -44,6 +44,7 @@ export default class BufferedConsole extends Console {
     type: LogType,
     message: LogMessage,
     level?: number | null,
+    api: LogApi = 'console',
   ): ConsoleBuffer {
     const stackLevel = level != null ? level : 2;
     const rawStack = new ErrorWithStack(undefined, BufferedConsole.write).stack;
@@ -57,6 +58,7 @@ export default class BufferedConsole extends Console {
       .join('\n');
 
     buffer.push({
+      api,
       message,
       origin,
       type,
@@ -71,6 +73,7 @@ export default class BufferedConsole extends Console {
       type,
       '  '.repeat(this._groupDepth) + message,
       3,
+      'console',
     );
   }
 

packages/jest-console/src/__tests__/bufferedConsole.test.ts

@@ -20,7 +20,7 @@ describe('CustomConsole', () => {
   };
 
   beforeEach(() => {
-    _console = new BufferedConsole(() => null);
+    _console = new BufferedConsole([]);
   });
 
   describe('assert', () => {

packages/jest-console/src/getConsoleOutput.ts

@@ -31,22 +31,21 @@ export default (
   const TITLE_INDENT = verbose ? '  ' : '    ';
   const CONSOLE_INDENT = TITLE_INDENT + '  ';
 
-  const logEntries = buffer.reduce((output, {type, message, origin}) => {
+  const logEntries = buffer.reduce((output, {api, type, message, origin}) => {
     message = message
       .split(/\n/)
       .map(line => CONSOLE_INDENT + line)
       .join('\n');
 
-    let typeMessage = 'console.' + type;
+    let typeMessage = `${api}.${type}`;
     let noStackTrace = true;
     let noCodeFrame = true;
-
     if (type === 'warn') {
       message = chalk.yellow(message);
       typeMessage = chalk.yellow(typeMessage);
       noStackTrace = globalConfig?.noStackTrace ?? false;
       noCodeFrame = false;
-    } else if (type === 'error') {
+    } else if (type === 'error' || api === 'process.stderr') {
       message = chalk.red(message);
       typeMessage = chalk.red(typeMessage);
       noStackTrace = globalConfig?.noStackTrace ?? false;

packages/jest-console/src/index.ts

@@ -9,4 +9,4 @@ export {default as BufferedConsole} from './BufferedConsole';
 export {default as CustomConsole} from './CustomConsole';
 export {default as NullConsole} from './NullConsole';
 export {default as getConsoleOutput} from './getConsoleOutput';
-export type {ConsoleBuffer, LogMessage, LogType} from './types';
+export type {ConsoleBuffer, LogApi, LogMessage, LogType} from './types';

packages/jest-console/src/types.ts

@@ -7,7 +7,10 @@
 
 export type LogMessage = string;
 
+export type LogApi = 'console' | 'process.stdout' | 'process.stderr';
+
 export type LogEntry = {
+  api: LogApi;
   message: LogMessage;
   origin: string;
   type: LogType;
@@ -33,6 +36,7 @@ export type LogType =
   | 'info'
   | 'log'
   | 'time'
-  | 'warn';
+  | 'warn'
+  | 'write';
 
 export type ConsoleBuffer = Array<LogEntry>;

packages/jest-core/src/__tests__/run_jest.test.js

@@ -9,35 +9,22 @@ import runJest from '../runJest';
 
 jest.mock('@jest/console');
 
-const processErrWriteFn = process.stderr.write;
 describe('runJest', () => {
-  let stderrSpy;
-  beforeEach(async () => {
-    process.exit = jest.fn();
-    process.stderr.write = jest.fn();
-    process.stderr.write.mockReset();
-    stderrSpy = jest.spyOn(process.stderr, 'write');
+  test('when watch is set then print error and exit process', async () => {
+    jest.spyOn(process, 'exit').mockImplementation(() => {});
 
     await runJest({
-      changedFilesPromise: Promise.resolve({repos: {git: {size: 0}}}),
+      changedFilesPromise: Promise.resolve({repos: {git: new Set()}}),
       contexts: [],
       globalConfig: {testSequencer: '@jest/test-sequencer', watch: true},
       onComplete: () => null,
       outputStream: {},
       startRun: {},
       testWatcher: {isInterrupted: () => true},
     });
-  });
 
-  afterEach(() => {
-    process.stderr.write = processErrWriteFn;
-  });
+    await new Promise(process.nextTick);
 
-  test('when watch is set then exit process', () => {
     expect(process.exit).toHaveBeenCalledWith(1);
   });
-
-  test('when watch is set then an error message is printed', () => {
-    expect(stderrSpy).toHaveBeenCalled();
-  });
 });

packages/jest-runner/package.json

@@ -28,6 +28,7 @@
     "jest-runtime": "^26.2.2",
     "jest-util": "^26.2.0",
     "jest-worker": "^26.2.1",
+    "readable-stream": "^3.1.1",
     "source-map-support": "^0.5.6",
     "throat": "^5.0.0"
   },