Avoid writing to stdout in default reporter if --json is enabled. Fixes

#3941 (#3945)

packages/jest-cli/src/reporters/__tests__/default_reporter.test.js

@@ -0,0 +1,78 @@
+/**
+ * Copyright (c) 2017-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.
+ */
+
+'use strict';
+
+const aggregatedResults = {};
+const options = {};
+const testCase = {
+  context: {config: {rootDir: '/'}},
+  duration: 0,
+  path: '/foo',
+};
+const testResult = {
+  testFilePath: '/foo',
+};
+
+let DefaultReporter;
+let stdout;
+let stderr;
+
+let oldIsTTY;
+let oldStderr;
+let oldStdout;
+
+beforeEach(() => {
+  jest.resetModules();
+  jest.useFakeTimers();
+
+  oldIsTTY = process.stdin.isTTY;
+  oldStdout = process.stdout.write;
+  oldStderr = process.stderr.write;
+
+  // We mock stderr (even if we do not use it right now on the tests) to avoid
+  // fake reporters created while testing to mess with the real output of the
+  // tests itself.
+  process.stdin.isTTY = true;
+  stdout = process.stdout.write = jest.fn();
+  stderr = process.stderr.write = jest.fn();
+
+  DefaultReporter = require('../default_reporter');
+});
+
+afterEach(() => {
+  process.stdin.isTTY = oldIsTTY;
+  process.stdout.write = oldStdout;
+  process.stderr.write = oldStderr;
+});
+
+test('normal output, everything goes to stdout', () => {
+  const reporter = new DefaultReporter({});
+
+  reporter.onRunStart(aggregatedResults, options);
+  reporter.onTestStart(testCase);
+  reporter.onTestResult(testCase, testResult, aggregatedResults);;
+  reporter.onRunComplete();
+
+  jest.runAllTimers();
+
+  expect(stdout).toHaveBeenCalled();
+});
+
+test('when using stderr as output, no stdout call is made', () => {
+  const reporter = new DefaultReporter({useStderr: true});
+
+  reporter.onRunStart(aggregatedResults, options);
+  reporter.onTestStart(testCase);
+  reporter.onTestResult(testCase, testResult, aggregatedResults);;
+  reporter.onRunComplete();
+
+  jest.runAllTimers();
+
+  expect(stdout).not.toHaveBeenCalled();
+});

packages/jest-cli/src/reporters/default_reporter.js

@@ -63,10 +63,14 @@ class DefaultReporter extends BaseReporter {
     const flushBufferedOutput = () => {
       const string = buffer.join('');
       buffer = [];
+
       // This is to avoid conflicts between random output and status text
       this._clearStatus();
-      originalWrite.call(stream, string);
+      if (string) {
+        originalWrite.call(stream, string);
+      }
       this._printStatus();
+
       this._bufferedOutput.delete(flushBufferedOutput);
     };
 
@@ -105,15 +109,23 @@ class DefaultReporter extends BaseReporter {
 
   _clearStatus() {
     if (isInteractive) {
-      this._out(this._clear);
+      if (this._globalConfig.useStderr) {
+        this._err(this._clear);
+      } else {
+        this._out(this._clear);
+      }
     }
   }
 
   _printStatus() {
     const {content, clear} = this._status.get();
     this._clear = clear;
     if (isInteractive) {
-      this._out(content);
+      if (this._globalConfig.useStderr) {
+        this._err(content);
+      } else {
+        this._out(content);
+      }
     }
   }
 

packages/jest-resolve/yarn.lock

@@ -2,6 +2,14 @@
 # yarn lockfile v1
 
 
+ansi-regex@^2.0.0:
+  version "2.1.1"
+  resolved "https://registry.yarnpkg.com/ansi-regex/-/ansi-regex-2.1.1.tgz#c3b33ab5ee360d86e0e628f0468ae7ef27d654df"
+
+ansi-styles@^2.2.1:
+  version "2.2.1"
+  resolved "https://registry.yarnpkg.com/ansi-styles/-/ansi-styles-2.2.1.tgz#b432dd3358b634cf75e1e4664368240533c1ddbe"
+
 browser-resolve@^1.11.2:
   version "1.11.2"
   resolved "https://registry.yarnpkg.com/browser-resolve/-/browser-resolve-1.11.2.tgz#8ff09b0a2c421718a1051c260b32e48f442938ce"
@@ -12,6 +20,26 @@ builtin-modules@^1.0.0:
   version "1.1.1"
   resolved "https://registry.yarnpkg.com/builtin-modules/-/builtin-modules-1.1.1.tgz#270f076c5a72c02f5b65a47df94c5fe3a278892f"
 
+chalk@^1.1.3:
+  version "1.1.3"
+  resolved "https://registry.yarnpkg.com/chalk/-/chalk-1.1.3.tgz#a8115c55e4a702fe4d150abd3872822a7e09fc98"
+  dependencies:
+    ansi-styles "^2.2.1"
+    escape-string-regexp "^1.0.2"
+    has-ansi "^2.0.0"
+    strip-ansi "^3.0.0"
+    supports-color "^2.0.0"
+
+escape-string-regexp@^1.0.2:
+  version "1.0.5"
+  resolved "https://registry.yarnpkg.com/escape-string-regexp/-/escape-string-regexp-1.0.5.tgz#1b61c0562190a8dff6ae3bb2cf0200ca130b86d4"
+
+has-ansi@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/has-ansi/-/has-ansi-2.0.0.tgz#34f5049ce1ecdf2b0649af3ef24e45ed35416d91"
+  dependencies:
+    ansi-regex "^2.0.0"
+
 is-builtin-module@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/is-builtin-module/-/is-builtin-module-1.0.0.tgz#540572d34f7ac3119f8f76c30cbc1b1e037affbe"
@@ -31,3 +59,13 @@ resolve@^1.3.2:
   resolved "https://registry.yarnpkg.com/resolve/-/resolve-1.3.3.tgz#655907c3469a8680dc2de3a275a8fdd69691f0e5"
   dependencies:
     path-parse "^1.0.5"
+
+strip-ansi@^3.0.0:
+  version "3.0.1"
+  resolved "https://registry.yarnpkg.com/strip-ansi/-/strip-ansi-3.0.1.tgz#6a385fb8853d952d5ff05d0e8aaf94278dc63dcf"
+  dependencies:
+    ansi-regex "^2.0.0"
+
+supports-color@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/supports-color/-/supports-color-2.0.0.tgz#535d045ce6b6363fa40117084629995e9df324c7"

types/TestRunner.js

@@ -17,8 +17,8 @@ import type Runtime from 'jest-runtime';
 
 export type Test = {|
   context: Context,
-  path: Path,
   duration: ?number,
+  path: Path,
 |};
 
 export type Reporter = {