Added options browser_tests using the generator and js handler framework.

This patch turned out to be fairly large.  Let me describe the ultimate goal:
- To write WebUI tests in javascript, with as little C++ as possible for the simple case, yet powerful enough to support more complicated cases.  options.js illustrates the simple case, and print_preview.js illustrates the complicated case.

Original changes:
- Refactored test_tab_strip_observer into test_navigation_observer so that it could be used by itself without needing the TabInsertedAt logic, which PrintPreview needs when there's no TabContentsWrapper available.
- Added assertEqualsArray for comparing two arrays shallowly (javascript == fails).
- Provided logic in WebUIBrowserTest and in the javascript2webui.js generation script to allow browsing to a url with preload of injected javascript.
- Corrected test_navigation_observer to wait for the right notification before calling callback (which runs after the page's javascript is loaded but before its onload).
- Added guts to define OS_* ifdefs for javascript to test for disabling tests.
- Moved the handler from settings_browsertest.cc to settings.js
- use __proto__ when overriding chrome to allow other members to be seen (commandLineString, e.g.)

Additions made during review:
- Switched to generative mechanism: TEST_F, GEN, which output during generation, and register during runtime.
- JS fixtures provide configuration members
- Add configuration hooks to generate in C++ test function
- Output directly to .cc file rather than needing hand-made .cc file which includes the generated file.
- Changed preload to take testFixture and testName.
- include and use mock4js to ensure handler methods are called.
- auto-generate the typedef WebUIBrowserTest testFixture unless overridden.

R=jhawkins@chromium.org,dtseng@chromium.org
BUG=None
TEST=browser_tests --gtest_filter=SettingsWebUITest.*

Review URL: http://codereview.chromium.org/7237030

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@92084 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 415 insertions, 28 deletions

diff --git a/chrome/test/data/webui/test_api.js b/chrome/test/data/webui/test_api.js
index c9dddc2..65e3f2f 100644
--- a/chrome/test/data/webui/test_api.js
+++ b/chrome/test/data/webui/test_api.js
@@ -2,13 +2,233 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Library providing basic test framework functionality.
+/**
+ * @fileoverview Library providing basic test framework functionality.
+ **/
+
+/**
+ * Namespace for |Test|.
+ * @type {Object}
+ **/
+var testing = {};
+
+/**
+ * Hold the currentTestCase across between PreLoad and Run.
+ * @type {TestCase}
+ **/
+var currentTestCase = null;
 
 (function() {
+  // Provide global objects for generation case.
+  if (this['window'] === undefined)
+    this['window'] = this;
+  if (this['chrome'] === undefined) {
+    this['chrome'] = {
+      send: function() {},
+    };
+  }
+  if (this['console'] === undefined) {
+    this['console'] = {
+      log: print,
+    };
+  }
+
+  /**
+   * This class will be exported as testing.Test, and is provided to hold the
+   * fixture's configuration and callback methods for the various phases of
+   * invoking a test. It is called "Test" rather than TestFixture to roughly
+   * mimic the gtest's class names.
+   * @constructor
+   **/
+  function Test() {}
+
+  Test.prototype = {
+    /**
+     * The name of the test.
+     **/
+    name: null,
+
+    /**
+     * When set to a string value representing a url, generate BrowsePreload
+     * call, which will browse to the url and call fixture.PreLoad of the
+     * currentTestCase.
+     * @type {String}
+     **/
+    browsePreload: null,
+
+    /**
+     * When set to a string value representing an html page in the test
+     * directory, generate BrowsePrintPreload call, which will browse to a url
+     * representing the file, cause print, and call fixture.PreLoad of the
+     * currentTestCase.
+     * @type {String}
+     **/
+    browsePrintPreload: null,
+
+    /**
+     * When set to a function, will be called in the context of the test
+     * generation inside the function, and before any generated C++.
+     * @type {function(string,string)}
+     **/
+    testGenPreamble: null,
+
+    /**
+     * When set to a function, will be called in the context of the test
+     * generation inside the function, and before any generated C++.
+     * @type {function(string,string)}
+     **/
+    testGenPostamble: null,
+
+    /**
+     * When set to a non-null String, auto-generate typedef before generating
+     * TEST*: {@code typedef typedefCppFixture testFixture}.
+     * @type {String}
+     **/
+    typedefCppFixture: 'WebUIBrowserTest',
+
+    /**
+     * This should be initialized by the test fixture and can be referenced
+     * during the test run.
+     * @type {Mock4JS.Mock}
+     **/
+    mockHandler: null,
+
+    /**
+     * Override this method to perform initialization during preload (such as
+     * creating mocks and registering handlers).
+     * @type {Function}
+     **/
+    PreLoad: function() {},
+
+    /**
+     * Override this method to perform tasks before running your test.
+     * @type {Function}
+     **/
+    SetUp: function() {},
+
+    /**
+     * Override this method to perform tasks after running your test. If you
+     * create a mock class, you must call Mock4JS.verifyAllMocks() in this
+     * phase.
+     * @type {Function}
+     **/
+    TearDown: function() {
+      Mock4JS.verifyAllMocks();
+    }
+  };
+
+  /**
+   * This class is not exported and is available to hold the state of the
+   * |currentTestCase| throughout preload and test run.
+   * @param {String} name The name of the test case.
+   * @param {Test} fixture The fixture object for this test case.
+   * @param {Function} body The code to run for the test.
+   * @constructor
+   **/
+  function TestCase(name, fixture, body) {
+    this.name = name;
+    this.fixture = fixture;
+    this.body = body;
+  }
+
+  TestCase.prototype = {
+    name: null,
+    fixture: null,
+    body: null,
+
+    /**
+     * Called at preload time, proxies to the fixture.
+     * @type {Function}
+     **/
+    PreLoad: function(name) {
+      if (this.fixture)
+        this.fixture.PreLoad();
+    },
+
+    /**
+     * Runs this test case.
+     * @type {Function}
+     **/
+    Run: function() {
+      if (this.fixture)
+        this.fixture.SetUp();
+      if (this.body)
+        this.body.call(this.fixture);
+      if (this.fixture)
+        this.fixture.TearDown();
+    },
+  };
+
+  /**
+   * Registry of javascript-defined callbacks for {@code chrome.send}.
+   * @type {Object}
+   **/
+  var sendCallbacks = {};
+
+  /**
+   * Registers the message, object and callback for {@code chrome.send}
+   * @param {String} name The name of the message to route to this |callback|.
+   * @param {Object} messageHAndler Pass as |this| when calling the |callback|.
+   * @param {function(...)} callback Called by {@code chrome.send}.
+   * @see sendCallbacks
+   **/
+  function registerMessageCallback(name, messageHandler, callback) {
+    sendCallbacks[name] = [messageHandler, callback];
+  }
+
+  /**
+   * Register all methods of {@code mockClass.prototype} with messages of the
+   * same name as the method, using the proxy of the |mockObject| as the
+   * |messageHandler| when registering.
+   * @param {Mock4JS.Mock} mockObject The mock to register callbacks against.
+   * @param {function(new:Object)} mockClAss Constructor for the mocked class.
+   * @see registerMessageCallback
+   **/
+  function registerMockMessageCallbacks(mockObject, mockClass) {
+    var mockProxy = mockObject.proxy();
+    for (func in mockClass.prototype) {
+      if (typeof(mockClass.prototype[func]) == 'function') {
+        registerMessageCallback(func,
+                                mockProxy,
+                                mockProxy[func]);
+      }
+    }
+  }
+
+  /**
+   * Holds the old chrome object when overriding for preload and registry of
+   * handlers.
+   * @type {Object}
+   **/
+  var oldChrome = chrome;
+
+  /**
+   * Overrides {@code chrome.send} for routing messages to javascript
+   * functions. Also fallsback to sending with the |oldChrome| object.
+   * @param {String} messageName The message to route.
+   * @see oldChrome
+   **/
+  function send(messageName) {
+    var callback = sendCallbacks[messageName];
+    var args = Array.prototype.slice.call(arguments, 1);
+    if (callback != undefined)
+      callback[1].apply(callback[0], args);
+    else
+      oldChrome.send.apply(oldChrome, args);
+  }
+
   // Asserts.
   // Use the following assertions to verify a condition within a test.
   // If assertion fails, the C++ backend will be immediately notified.
   // If assertion passes, no notification will be sent to the C++ backend.
+
+  /**
+   * When |test| !== |expected|, aborts the current test.
+   * @param {Boolean} test The predicate to check against |expected|.
+   * @param {Boolean} expected The expected value of |test|.
+   * @param {String=} message The message to include in the Error thrown.
+   * @throws {Error} upon failure.
+   **/
   function assertBool(test, expected, message) {
     if (test !== expected) {
       if (message)
@@ -19,30 +239,33 @@
     }
   }
 
-  var old_chrome = chrome;
-  var send_callbacks = {};
-
-  function registerMessageCallback(name, object, callback) {
-    send_callbacks[name] = [object, callback];
-  }
-
-  function send(messageName) {
-    var callback = send_callbacks[messageName];
-    var args = Array.prototype.slice.call(arguments, 1);
-    if (callback != undefined)
-      callback[1].apply(callback[0], args);
-    else
-      old_chrome.send.apply(old_chrome, args);
-  }
-
+  /**
+   * When |test| !== true, aborts the current test.
+   * @param {Boolean} test The predicate to check against |expected|.
+   * @param {String=} message The message to include in the Error thrown.
+   * @throws {Error} upon failure.
+   **/
   function assertTrue(test, message) {
     assertBool(test, true, message);
   }
 
+  /**
+   * When |test| !== false, aborts the current test.
+   * @param {Boolean} test The predicate to check against |expected|.
+   * @param {String=} message The message to include in the Error thrown.
+   * @throws {Error} upon failure.
+   **/
   function assertFalse(test, message) {
     assertBool(test, false, message);
   }
 
+  /**
+   * When |expected| !== |actual|, aborts the current test.
+   * @param {*} expected The predicate to check against |expected|.
+   * @param {*} actual The expected value of |test|.
+   * @param {String=} message The message to include in the Error thrown.
+   * @throws {Error} upon failure.
+   **/
   function assertEquals(expected, actual, message) {
     if (expected != actual) {
       throw new Error('Test Error. Actual: ' + actual + '\nExpected: ' +
@@ -55,56 +278,220 @@
     }
   }
 
+  /**
+   * Always aborts the current test.
+   * @param {String=} message The message to include in the Error thrown.
+   * @throws {Error} always.
+   **/
   function assertNotReached(message) {
     throw new Error(message);
   }
 
+  /**
+   * Holds the errors, if any, caught by expects so that the test case can fail.
+   * @type {Array.<Error>}
+   **/
   var errors = [];
 
+  /**
+   * Creates a function based upon a function that thows an exception on
+   * failure. The new function stuffs any errors into the |errors| array for
+   * checking by runTest. This allows tests to continue running other checks,
+   * while failing the overal test if any errors occurrred.
+   * @param {Function} assertFunc The function which may throw an Error.
+   * @return {Function} A function that applies its arguments to |assertFunc|.
+   * @see errors
+   * @see runTest
+   **/
   function createExpect(assertFunc) {
     return function() {
       try {
         assertFunc.apply(null, arguments);
       } catch (e) {
-        console.log('Failed: ' + currentTest.name + '\n' + e.stack);
         errors.push(e);
       }
     };
   }
 
+  /**
+   * This is the starting point for tests run by WebUIBrowserTest. It clears
+   * |errors|, runs the test surrounded by an expect to catch Errors. If
+   * |errors| is non-empty, it reports a failure and a message by joining
+   * |errors|.
+   * @param {String} testFunction The function name to call.
+   * @param {Array} testArguments The arguments to call |testFunction| with.
+   * @return {Array.<Boolean, String>} [test-succeeded, message-if-failed]
+   * @see errors
+   * @see createExpect
+   **/
   function runTest(testFunction, testArguments) {
     errors = [];
     // Avoid eval() if at all possible, since it will not work on pages
     // that have enabled content-security-policy.
-    currentTest = this[testFunction];    // global object -- not a method.
-    if (typeof currentTest === "undefined") {
-      currentTest = eval(testFunction);
-    }
-    console.log('Running test ' + currentTest.name);
-    createExpect(currentTest).apply(null, testArguments);
+    var testBody = this[testFunction];    // global object -- not a method.
+    if (typeof testBody === "undefined")
+      testBody = eval(testFunction);
+    if (testBody != RUN_TEST_F)
+      console.log('Running test ' + testBody.name);
+    createExpect(testBody).apply(null, testArguments);
 
     if (errors.length) {
+      for (var i = 0; i < errors.length; ++i) {
+        console.log('Failed: ' + testFunction + '(' +
+                    testArguments.toString() + ')\n' + errors[i].stack);
+      }
       return [false, errors.join('\n')];
+    } else {
+      return [true];
     }
+  }
 
-    return [true];
+  /**
+   * Creates a new test case for the given |testFixture| and |testName|. Assumes
+   * |testFixture| describes a globally available subclass of type Test.
+   * @param {String} testFixture The fixture for this test case.
+   * @param {String} testName The name for this test case.
+   * @return {TestCase} A newly created TestCase.
+   **/
+  function createTestCase(testFixture, testName) {
+    var fixtureConstructor = this[testFixture];
+    var testBody = fixtureConstructor.testCaseBodies[testName];
+    var fixture = new fixtureConstructor();
+    fixture.name = testFixture;
+    return new TestCase(testName, fixture, testBody);
   }
 
-  function preloadJavascriptLibraries(overload_chrome_send) {
-    if (overload_chrome_send)
-      chrome = { 'send': send };
+  /**
+   * Used by WebUIBrowserTest to preload the javascript libraries at the
+   * appropriate time for javascript injection into the current page. This
+   * creates a test case and calls its PreLoad for any early initialization such
+   * as registering handlers before the page's javascript runs it's OnLoad
+   * method.
+   * @param {String} testFixture The test fixture name.
+   * @param {String} testName The test name.
+   **/
+  function preloadJavascriptLibraries(testFixture, testName) {
+    chrome = {
+      __proto__: oldChrome,
+      send: send,
+    };
+    currentTestCase = createTestCase(testFixture, testName);
+    currentTestCase.PreLoad();
+  }
+
+  /**
+   * During generation phase, this outputs; do nothing at runtime.
+   **/
+  function GEN() {}
+
+  /**
+   * At runtime, register the testName with a test fixture. Since this method
+   * doesn't have a test fixture, we create a dummy fixture to hold its |name|
+   * and |testCaseBodies|.
+   * @param {String} testCaseName The name of the test case.
+   * @param {String} testName The name of the test function.
+   * @param {Function} testBody The body to execute when running this test.
+   **/
+  function TEST(testCaseName, testName, testBody) {
+    var fixtureConstructor = this[testCaseName];
+    if (fixtureConstructor === undefined) {
+      fixtureConstructor = function() {};
+      this[testCaseName] = fixtureConstructor;
+      fixtureConstructor.prototype = {
+        __proto__: Test.prototype,
+        name: testCaseName,
+      };
+      fixtureConstructor.testCaseBodies = {};
+    }
+    fixtureConstructor.testCaseBodies[testName] = testBody;
+  }
+
+  /**
+   * At runtime, register the testName with its fixture. Stuff the |name| into
+   * the |testFixture|'s prototype, if needed, and the |testCaseBodies| into its
+   * constructor.
+   * @param {String} testFixture The name of the test fixture class.
+   * @param {String} testName The name of the test function.
+   * @param {Function} testBody The body to execute when running this test.
+   **/
+  function TEST_F(testFixture, testName, testBody) {
+    var fixtureConstructor = this[testFixture];
+    if (!fixtureConstructor.prototype.name)
+      fixtureConstructor.prototype.name = testFixture;
+    if (fixtureConstructor['testCaseBodies'] === undefined)
+      fixtureConstructor.testCaseBodies = {};
+    fixtureConstructor.testCaseBodies[testName] = testBody;
+  }
+
+  /**
+   * RunJavascriptTestF uses this as the |testFunction| when invoking
+   * runTest. If |currentTestCase| is non-null at this point, verify that
+   * |testFixture| and |testName| agree with the preloaded values. Create
+   * |currentTestCase|, if needed, run it, and clear the |currentTestCase|.
+   * @param {String} testFixture The name of the test fixture class.
+   * @param {String} testName The name of the test function.
+   * @see preloadJavascriptLibraries
+   * @see runTest
+   **/
+  function RUN_TEST_F(testFixture, testName) {
+    if (!currentTestCase)
+      currentTestCase = createTestCase(testFixture, testName);
+    assertEquals(currentTestCase.name, testName);
+    assertEquals(currentTestCase.fixture.name, testFixture);
+    console.log('Running TestCase ' + testFixture + '.' + testName);
+    currentTestCase.Run();
+    currentTestCase = null;
+  }
+
+  /**
+   * CallFunctionAction is provided to allow mocks to have side effects.
+   * @param {Function} func The function to call.
+   * @param {Array} args Any arguments to pass to func.
+   * @constructor
+   **/
+  function CallFunctionAction(func, args) {
+    this._func = func;
+    this._args = args;
+  }
+
+  CallFunctionAction.prototype = {
+    invoke: function() {
+      return this._func.apply(null, this._args);
+    },
+    describe: function() {
+      return 'calls the given function with arguments ' + this._args;
+    }
+  };
+
+  /**
+   * Syntactic sugar for will() on a Mock4JS.Mock.
+   * @param {Function} func the function to call when the method is invoked.
+   * @param {...*} var_args arguments to pass when calling func.
+   **/
+  function callFunction(func) {
+    return new CallFunctionAction(func,
+                                  Array.prototype.slice.call(arguments, 1));
   }
 
   // Exports.
+  testing.Test = Test;
   window.assertTrue = assertTrue;
   window.assertFalse = assertFalse;
   window.assertEquals = assertEquals;
   window.assertNotReached = assertNotReached;
+  window.callFunction = callFunction;
   window.expectTrue = createExpect(assertTrue);
   window.expectFalse = createExpect(assertFalse);
   window.expectEquals = createExpect(assertEquals);
   window.expectNotReached = createExpect(assertNotReached);
   window.registerMessageCallback = registerMessageCallback;
+  window.registerMockMessageCallbacks = registerMockMessageCallbacks;
   window.runTest = runTest;
   window.preloadJavascriptLibraries = preloadJavascriptLibraries;
+  window.TEST = TEST;
+  window.TEST_F = TEST_F;
+  window.GEN = GEN;
+
+  // Import the Mock4JS helpers.
+  Mock4JS.addMockSupport(window);
 })();