1 files changed, 65 insertions, 0 deletions
diff --git a/remote/test/puppeteer/test-browser/debug.spec.js b/remote/test/puppeteer/test-browser/debug.spec.js
new file mode 100644
index 0000000000..971d3a5346
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+++ b/remote/test/puppeteer/test-browser/debug.spec.js
@@ -0,0 +1,65 @@
+/**
+ * Copyright 2020 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { debug } from '../lib/esm/puppeteer/common/Debug.js';
+import expect from '../node_modules/expect/build-es5/index.js';
+
+describe('debug', () => {
+  let originalLog;
+  let logs;
+  beforeEach(() => {
+    originalLog = console.log;
+    logs = [];
+    console.log = (...args) => {
+      logs.push(args);
+    };
+  });
+
+  afterEach(() => {
+    console.log = originalLog;
+  });
+
+  it('should return a function', async () => {
+    expect(debug('foo')).toBeInstanceOf(Function);
+  });
+
+  it('does not log to the console if __PUPPETEER_DEBUG global is not set', async () => {
+    const debugFn = debug('foo');
+    debugFn('lorem', 'ipsum');
+
+    expect(logs.length).toEqual(0);
+  });
+
+  it('logs to the console if __PUPPETEER_DEBUG global is set to *', async () => {
+    globalThis.__PUPPETEER_DEBUG = '*';
+    const debugFn = debug('foo');
+    debugFn('lorem', 'ipsum');
+
+    expect(logs.length).toEqual(1);
+    expect(logs).toEqual([['foo:', 'lorem', 'ipsum']]);
+  });
+
+  it('logs only messages matching the __PUPPETEER_DEBUG prefix', async () => {
+    globalThis.__PUPPETEER_DEBUG = 'foo';
+    const debugFoo = debug('foo');
+    const debugBar = debug('bar');
+    debugFoo('a');
+    debugBar('b');
+
+    expect(logs.length).toEqual(1);
+    expect(logs).toEqual([['foo:', 'a']]);
+  });
+});