DevTools: improve test infrastructure w/ devtools driving the test

third_party/WebKit/Source/devtools/front_end/test_runner/TestRunner.js

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /* eslint-disable no-console */
 
-/** @type {!{notifyDone: function()}|undefined} */
+/** @type {!{logToStderr: function(), notifyDone: function()}|undefined} */
 self.testRunner;
 
-TestRunner.executeTestScript = function() {
+TestRunner.start = function() {
   fetch(`${Runtime.queryParam('test')}`)
       .then(data => data.text())
       .then(testScript => eval(`(function(){${testScript}})()`))
       .catch(error => {
         TestRunner.addResult(`Unable to execute test script because of error: ${error}`);
         TestRunner.completeTest();
       });
 };
 
 /** @type {!Array<string>} */
@@ skipping 29 matching lines @@
  * @param {*} text
  */
 TestRunner.addResult = function(text) {
   if (self.testRunner)
     TestRunner._results.push(String(text));
   else
     console.log(text);
 };
 
 /**
+ * @param {!Array<string>} textArray
+ */
+TestRunner.addResults = function(textArray) {
+  if (!textArray)
+    return;
+  for (var i = 0, size = textArray.length; i < size; ++i)
+    TestRunner.addResult(textArray[i]);
+};
+
+/**
  * @param {!Array<function()>} tests
  */
 TestRunner.runTests = function(tests) {
   nextTest();
 
   function nextTest() {
     var test = tests.shift();
     if (!test) {
       TestRunner.completeTest();
       return;
     }
     TestRunner.addResult('\ntest: ' + test.name);
     var testPromise = test();
     if (!(testPromise instanceof Promise))
       testPromise = Promise.resolve();
     testPromise.then(nextTest);
   }
 };
 
 /**
  * @param {!Object} receiver
  * @param {string} methodName
+ * @param {!Function} override
+ * @param {boolean} opt_sticky
+ */
+TestRunner.addSniffer = function(receiver, methodName, override, opt_sticky) {

[dgozman, 2017/03/10 00:17:17]

General question: should we use this opportunity to make better test helpers, or
we'll be able to migrate many existing tests automatically at once?

+  override = TestRunner.safeWrap(override);
+
+  var original = receiver[methodName];
+  if (typeof original !== 'function')
+    throw new Error('Cannot find method to override: ' + methodName);
+
+  receiver[methodName] = function(var_args) {
+    try {
+      var result = original.apply(this, arguments);
+    } finally {
+      if (!opt_sticky)
+        receiver[methodName] = original;
+    }
+    // In case of exception the override won't be called.
+    try {
+      Array.prototype.push.call(arguments, result);
+      override.apply(this, arguments);
+    } catch (e) {
+      throw new Error('Exception in overriden method \'' + methodName + '\': ' + e);
+    }
+    return result;
+  };
+};
+
+/**
+ * @param {!Object} receiver
+ * @param {string} methodName
  * @return {!Promise<*>}
  */
-TestRunner.addSniffer = function(receiver, methodName) {
+TestRunner.addSnifferPromise = function(receiver, methodName) {
   return new Promise(function(resolve, reject) {
     var original = receiver[methodName];
     if (typeof original !== 'function') {
       reject('Cannot find method to override: ' + methodName);
       return;
     }
 
     receiver[methodName] = function(var_args) {
       try {
         var result = original.apply(this, arguments);
@@ skipping 15 matching lines @@
 
 /**
  * @param {!Array<string>} lazyModules
  * @return {!Promise<!Array<undefined>>}
  */
 TestRunner.loadLazyModules = function(lazyModules) {
   return Promise.all(lazyModules.map(lazyModule => self.runtime.loadModulePromise(lazyModule)));
 };
 
 /**
+ * @param {!Array<string>} panels
+ * @return {!Promise<!Array<!UI.Panel>>}
+ */
+TestRunner.loadPanels = function(panels) {
+  return Promise.all(panels.map(panel => UI.inspectorView.panel(panel)));
+};
+
+/**
  * @param {string} key
  * @param {boolean=} ctrlKey
  * @param {boolean=} altKey
  * @param {boolean=} shiftKey
  * @param {boolean=} metaKey
  * @return {!KeyboardEvent}
  */
 TestRunner.createKeyEvent = function(key, ctrlKey, altKey, shiftKey, metaKey) {
   return new KeyboardEvent('keydown', {
     key: key,
     bubbles: true,
     cancelable: true,
     ctrlKey: !!ctrlKey,
     altKey: !!altKey,
     shiftKey: !!shiftKey,
     metaKey: !!metaKey
   });
 };
 
+/**
+ * @param {!Function} func
+ * @param {!Function=} onexception
+ * @return {function()}
+ */
+TestRunner.safeWrap = function(func, onexception) {
+  /**
+   * @this {*}
+   */
+  function result() {
+    if (!func)
+      return;
+    var wrapThis = this;
+    try {
+      return func.apply(wrapThis, arguments);
+    } catch (e) {
+      TestRunner.addResult('Exception while running: ' + func + '\n' + (e.stack || e));
+      if (onexception)
+        TestRunner.safeWrap(onexception)();
+      else
+        TestRunner.completeTest();
+    }
+  }
+  return result;
+};
+
 (function() {
   /**
    * @param {string|!Event} message
    * @param {string} source
    * @param {number} lineno
    * @param {number} colno
    * @param {!Error} error
    */
   function completeTestOnError(message, source, lineno, colno, error) {
     TestRunner.addResult('TEST ENDED IN ERROR: ' + error.stack);
     TestRunner.completeTest();
   }
 
   self['onerror'] = completeTestOnError;
 })();