Add support in test scripts backend for simple HTML tests.

tools/testing/dart/browser_controller.dart

Index: tools/testing/dart/browser_controller.dart
diff --git a/tools/testing/dart/browser_controller.dart b/tools/testing/dart/browser_controller.dart
index d5bd5efae9dcc69902a090f9a90126d942019cee..2f8979ba8b1f718631465e294108bfcd30c80d1b 100644
--- a/tools/testing/dart/browser_controller.dart
+++ b/tools/testing/dart/browser_controller.dart
@@ -4,7 +4,7 @@
 library browser;
 
 import "dart:async";
-import "dart:convert" show LineSplitter, UTF8;
+import "dart:convert" show LineSplitter, UTF8, JSON;
 import "dart:core";
 import "dart:io";
 
@@ -785,6 +785,18 @@ class BrowserTest {
   }
 }
 
+
+/**
+ * Describes a test with a custom HTML page to be run in the browser.
+ */
+class HtmlTest extends BrowserTest {
+  List<String> expectedMessages;
+
+  HtmlTest(url, doneCallback, timeout, this.expectedMessages)
+      : super(url, doneCallback, timeout) { }
+}
+
+
 /* Describes the output of running the test in a browser */
 class BrowserTestOutput {
   final Duration delayUntilTestStarted;
@@ -1302,7 +1314,7 @@ class BrowserTestingServer {
                                      "no-cache, no-store, must-revalidate");
     }
     int testId(request) =>
-        int.parse(request.uri.queryParameters["id"].split("=")[1]);
+        int.parse(request.uri.queryParameters["id"]);
     String browserId(request, prefix) =>
         request.uri.path.substring(prefix.length + 1);
 
@@ -1388,8 +1400,15 @@ class BrowserTestingServer {
     } else if (nextTest == null) {
       // We don't currently have any tests ready for consumption, wait.
       return waitSignal;
+    } else if (nextTest is HtmlTest){

[ricow1, 2014/10/07 12:46:21]

add a toJSON to the BrowserTest and overwrite it in HtmlTest, remove type
testing here?

[Bill Hesse, 2014/10/07 15:28:34]

Done.

+      return JSON.encode({'url': nextTest.url,
+                          'id': nextTest.id,
+                          'isHtmlTest': true,
+                          'expectedMessages': nextTest.expectedMessages});
     } else {
-      return "${nextTest.url}#id=${nextTest.id}";
+      return JSON.encode({'url': nextTest.url,
+                          'id': nextTest.id,
+                          'isHtmlTest': false});
     }
   }
 
@@ -1429,6 +1448,9 @@ class BrowserTestingServer {
       var use_iframe = ${useIframe};
       var start = new Date();
 
+      // Object that holds the state of an HTML test
+      var html_test;
+  
       function newTaskHandler() {
         if (this.readyState == this.DONE) {
           if (this.status == 200) {
@@ -1438,12 +1460,24 @@ class BrowserTestingServer {
               // Don't do anything, we will be killed shortly.
             } else {
               var elapsed = new Date() - start;
-              // The task is send to us as:
-              // URL#ID
-              var split = this.responseText.split('#');
-              var nextTask = split[0];
-              next_id = split[1];
-              run(nextTask);
+              var nextTask = JSON.parse(this.responseText);
+              var url = nextTask.url;
+              next_id = nextTask.id;
+              if (nextTask.isHtmlTest) {
+                html_test = {
+                  expected_messages: nextTask.expectedMessages,
+                  found_message_count: 0,
+                  double_received_messages: [],
+                  unexpected_messages: [],
+                  found_messages: {}
+                };
+                for (var i = 0; i < html_test.expected_messages.length; ++i) {
+                  html_test.found_messages[html_test.expected_messages[i]] = 0;
+                }
+              } else {
+                html_test = null;
+              }               
+              run(url);
             }
           } else {
             reportError('Could not contact the server and get a new task');
@@ -1473,11 +1507,49 @@ class BrowserTestingServer {
             'GET', '$nextTestPath/$browserId', newTaskHandler, "", false);
       }
 
+      function childError(message, filename, lineno, colno, error) {
+        if (error) {
+          reportMessage('FAIL:' + filename + ':' + lineno + 
+               ':' + colno + ':' + message + '\\n' + error.stack, false, false);
+        } else if (filename) {
+          reportMessage('FAIL:' + filename + ':' + lineno + 
+               ':' + colno + ':' + message, false, false);
+        } else {
+          reportMessage('FAIL: ' + message, false, false);
+        }
+        return true;
+      }
+
+      function setChildHandlers(e) {
+        embedded_iframe.contentWindow.addEventListener('message',
+                                                       childMessageHandler,
+                                                       false);
+        embedded_iframe.contentWindow.onerror = childError;
+        reportMessage("First message from html test", true, false);
+        html_test.handlers_installed = true;
+      }
+
+      function checkChildHandlersInstalled() {
+        if (!html_test.handlers_installed) {
+          reportMessage("First message from html test", true, false);
+          reportMessage(
+              'FAIL: Html test did not call ' +
+              'window.parent.dispatchEvent(new Event("detect_errors")) ' +
+              'as its first action', false, false);
+        }
+      }
+
       function run(url) {
         number_of_tests++;
         number_div.innerHTML = number_of_tests;
         executing_div.innerHTML = url;
         if (use_iframe) {
+          if (html_test) {
+            window.addEventListener('detect_errors', setChildHandlers, false);
+            embedded_iframe.onload = checkChildHandlersInstalled;
+          } else {
+            embedded_iframe.onload = null;
+          }
           embedded_iframe.src = url;
         } else {
           if (typeof testing_window != 'undefined') {
@@ -1558,6 +1630,7 @@ class BrowserTestingServer {
         return parsedData;
       }
 
+      // Browser tests send JSON messages to the driver window, handled here.
       function messageHandler(e) {
         var msg = e.data;
         if (typeof msg != 'string') return;
@@ -1585,9 +1658,41 @@ class BrowserTestingServer {
         }
       }
 
-      window.addEventListener('message', messageHandler, false);
-      waitForDone = false;
+      function reportHtmlTestWarning () {
+        reportMessage('Warning:\\n  Messages received multiple times:\\n    ' +
+                      html_test.double_received_messages +
+                      '\\n  Unexpected messages:\\n    ' +
+                      html_test.unexpected_messages, false, true);
+      }
 
+      // HTML tests post messages to their own window, handled by this handler.
+      // This handler is installed on the child window when it sends the
+      // 'detect_errors' event.  Every HTML test must send 'detect_errors' to
+      // its parent window as its first action, so all errors will be caught.
+      function childMessageHandler(e) {
+        var msg = e.data;
+        if (typeof msg != 'string') return;

[ricow1, 2014/10/07 12:46:21]

what would this mean?

[Bill Hesse, 2014/10/07 15:28:34]

Apparently, things other than strings can be posted to the window.

+        if (msg in html_test.found_messages) {
+          html_test.found_messages[msg]++;
+          if (html_test.found_messages[msg] == 1) {
+            html_test.found_message_count++;
+          } else {  
+            html_test.double_received_messages.push(msg);

[ricow1, 2014/10/07 12:46:21]

I am thinking this could be an error (I am so beeping sick of the existing
double reporting tests, making this an error should at least make it better for
this category of tests)

[Bill Hesse, 2014/10/07 15:28:34]

Lets think about this.  It is easy to change.

+            reportHtmlTestWarning();
+          }
+        } else {
+          html_test.unexpected_messages.push(msg);
+          reportHtmlTestWarning();

[ricow1, 2014/10/07 12:46:21]

same comment as above, or do we expect this?

[Bill Hesse, 2014/10/07 15:28:34]

I think it might be more reasonable to expect this - some framework, or some new
library, could send messages to the window object, and the test should just
ignore them.  I know there is a comment that polymer sends doubles to the window
as messages - that is why we only look at strings.

+        }
+        if (html_test.found_message_count == html_test.expected_messages.length) {

[Bill Hesse, 2014/10/07 12:09:56]

Long line fixed.

+          reportMessage('Test done: PASS', false, false);
+        }
+      }
+
+      if (!html_test) {
+        window.addEventListener('message', messageHandler, false);
+        waitForDone = false;
+      }
       getNextTask();
     }