fix --logHeapUsage (jestjs#4176)

integration_tests/__tests__/log_heap_usage.test.js

@@ -0,0 +1,34 @@
+/**
+ * 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
+ */
+
+'use strict';
+
+const path = require('path');
+const os = require('os');
+const skipOnWindows = require('../../scripts/skip_on_windows');
+const {cleanup, writeFiles} = require('../utils');
+const runJest = require('../runJest');
+
+const DIR = path.resolve(os.tmpdir(), 'log_heap_usage_test');
+
+skipOnWindows.suite();
+
+beforeEach(() => cleanup(DIR));
+afterAll(() => cleanup(DIR));
+
+test('logs memory usage', () => {
+  writeFiles(DIR, {
+    '__tests__/a-banana.js': `test('banana', () => expect(1).toBe(1));`,
+    'package.json': JSON.stringify({jest: {testEnvironment: 'node'}}),
+  });
+
+  const {stderr} = runJest(DIR, ['--logHeapUsage']);
+  expect(stderr).toMatch(/PASS\s{2}__tests__\/a-banana.js.*\d+ MB heap size/);
+});

packages/jest-cli/src/run_test.js

@@ -109,7 +109,7 @@ function runTest(
       result =>
         Promise.resolve().then(() => {
           environment.dispose();
-          if (config.logHeapUsage) {
+          if (globalConfig.logHeapUsage) {
             if (global.gc) {
               global.gc();
             }