Add some closureised JS bindings for DevTools for use by headless embedder

headless/test/test_harness.js

+// Copyright 2017 The Chromium Authors. All rights reserved.

[Sami, 2017/05/24 09:16:22]

Could we reuse an existing test framework (jstest?) instead of rolling our own?
I think that's what's recommended for layout tests these days.

[alex clarke (OOO till 29th), 2017/05/24 11:38:17]

Is that in chromium somewhere?
Most existing js test frameworks I'm familiar with (e.g. Karma) are
inappropriate here since they typically have their own webkit backend.

[Sami, 2017/05/25 17:53:35]

Sorry, meant testharness.js. See here:
https://cs.chromium.org/chromium/src/third_party/WebKit/LayoutTests/resources...

[alex clarke (OOO till 29th), 2017/05/26 11:37:02]

As discussed offline I refactored the test se we don't need this.

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+goog.require('goog.DevTools.Connection');
+goog.provide('goog.DevTools.TestHarness');
+
+goog.scope(function() {
+
+/**
+ * The DevTools connection
+ *
+ * @private {!goog.DevTools.Connection}
+ */
+goog.DevTools.TestHarness.connection_ =
+    new goog.DevTools.Connection(window.TabSocket);
+
+/**
+ * Asks the C++ test harness to quit.
+ *
+ * @private
+ */
+goog.DevTools.TestHarness.QuitTest_ = function() {
+  goog.DevTools.TestHarness.connection_.SendDevToolsMessage('__QuitTest', {});
+};
+
+/**
+ * Used to report a test failure.
+ *
+ * @param {string} error The error message to report.
+ */
+goog.DevTools.TestHarness.FailTest = function(error) {
+  goog.DevTools.TestHarness.connection_.SendDevToolsMessage('__FailTest',
+                                                            {"error": error});
+};
+
+/**
+ * Asks the C++ test harness to log a message.
+ *
+ * @param {string} message The message to report.
+ */
+goog.DevTools.TestHarness.Log = function(message) {
+  goog.DevTools.TestHarness.connection_.SendDevToolsMessage(
+      '__Log', {"message": message});
+};
+
+/**
+ * @class A simple asynchronous test class.
+ * @param {!goog.DevTools.Connection} connection The DevTools connection.
+ * @param {string} testName The name of the test to run.
+ * @param {!function(!goog.DevTools.Test)} testFunction The test function
+ * @constructor
+ */
+goog.DevTools.Test = function(connection, testName, testFunction) {
+  /**
+   * @type {!goog.DevTools.Connection}
+   */
+  this.connection_ = connection;
+
+  /**
+   * @type {string}
+   */
+  this.testName_ = testName;
+
+  /**
+   * @type {!function(!goog.DevTools.Test)}
+   */
+  this.testFunction_ = testFunction;
+
+  /**
+   * @private {boolean}
+   */
+  this.testPassed_ = true;
+};
+
+/**
+ * Used to report a test failure.
+ *
+ * @param {string} error The error message to report.
+ */
+goog.DevTools.Test.prototype.Fail = function(error) {
+  this.testPassed_ = false;
+  goog.DevTools.TestHarness.Log(error);
+};
+
+
+/**
+ * Compares two JavaScript values for type and value equality.
+ * It checks internals of arrays and objects.
+ */
+function deepEquals(a, b) {
+  if (a === b) {
+    // Check for -0.
+    if (a === 0) return (1 / a) === (1 / b);
+    return true;
+  }
+  if (typeof a != typeof b) return false;
+  if (typeof a == 'number') return isNaN(a) && isNaN(b);
+  if (typeof a !== 'object' && typeof a !== 'function') return false;
+  // Neither a nor b is primitive.
+  var objectClass = classOf(a);
+  if (objectClass !== classOf(b)) return false;
+  if (objectClass === 'RegExp') {
+    // For RegExp, just compare pattern and flags using its toString.
+    return (a.toString() === b.toString());
+  }
+  // Functions are only identical to themselves.
+  if (objectClass === 'Function') return false;
+  if (objectClass === 'Array') {
+    var elementCount = 0;
+    if (a.length != b.length) {
+      return false;
+    }
+    for (var i = 0; i < a.length; i++) {
+      if (!deepEquals(a[i], b[i])) return false;
+    }
+    return true;
+  }
+  if (objectClass == 'String' || objectClass == 'Number' ||
+      objectClass == 'Boolean' || objectClass == 'Date') {
+    if (a.valueOf() !== b.valueOf()) return false;
+  }
+  return deepObjectEquals(a, b);
+}
+
+
+/**
+ * @param {*} expected The expected result.
+ * @param {*} found The value found.
+ * @param {string=} opt_message Optional message.
+ */
+goog.DevTools.Test.prototype.AssertEq = function(expected, found, opt_message) {
+  if (!deepEquals(expected, found)) {
+    this.Fail('Expected \'' + JSON.stringify(expected) +'\' but found \'' +
+              JSON.stringify(found) + '\' ' + (opt_message ? opt_message : ''));
+  }
+};
+
+
+/**
+ * Used to report the end of the test.
+ */
+goog.DevTools.Test.prototype.Finish = function() {
+  if (this.testPassed_) {
+    goog.DevTools.TestHarness.Log('[       OK ] ' + this.testName_);
+    goog.DevTools.TestHarness.RunTests();
+  } else {
+    goog.DevTools.TestHarness.FailTest('[     FAIL ] ' + this.testName_);
+  }
+};
+
+
+/**
+ * The tests to run.
+ *
+ * @private {!Array.<!goog.DevTools.Test>}
+ */
+goog.DevTools.TestHarness.tests_ = [];
+
+/**
+ * Asks the C++ test harness to quit and report an error.
+ *
+ * @param {string} testName The name of the test to run.
+ * @param {!function(!goog.DevTools.Test)} testFunction A test to run.
+ */
+goog.DevTools.TestHarness.AddTest = function(testName, testFunction) {
+  goog.DevTools.TestHarness.tests_.push(
+      new goog.DevTools.Test(goog.DevTools.TestHarness.connection_, testName,
+                             testFunction));
+};
+
+/**
+ * Runs the next test in the list.
+ */
+goog.DevTools.TestHarness.RunTests = function() {
+  let test = goog.DevTools.TestHarness.tests_.shift();
+  if (test === undefined) {
+    goog.DevTools.TestHarness.QuitTest_();
+  } else {
+    goog.DevTools.TestHarness.Log('[ RUN      ] ' + test.testName_);
+    test.testFunction_(test);
+  }
+};
+
+});  // goog.scope