Bug 1146566 - 1 - Use devtools common frame-script in markupview tests and add helper; r=bgrins

This change loads the devtools common frame-script-utils.js frame-script in the browser message
manager when a new test tab is opened by a test, and it adds a new getDomElementInfo message
listener useful for many tests to retrieve data about a node without having to go through a
CPOW.

--HG--
extra : rebase_source : 7783609faa96ba9a321156f781101244acd9ae2d
extra : histedit_source : 171b976aa669f59342d31dbe278cda3769988c2b%2C5c1851a0090c961e04c26ecdc167b4c4b965c73f

browser/devtools/markupview/test/head.js

@@ -48,6 +48,7 @@ registerCleanupFunction(function*() {
 
 const TEST_URL_ROOT = "http://mochi.test:8888/browser/browser/devtools/markupview/test/";
 const CHROME_BASE = "chrome://mochitests/content/browser/browser/devtools/markupview/test/";
+const COMMON_FRAME_SCRIPT_URL = "chrome://browser/content/devtools/frame-script-utils.js";
 
 /**
  * Add a new test tab in the browser and load the given url.
@@ -66,6 +67,9 @@ function addTab(url) {
   let tab = window.gBrowser.selectedTab = window.gBrowser.addTab(url);
   let linkedBrowser = tab.linkedBrowser;
 
+  info("Loading the helper frame script " + COMMON_FRAME_SCRIPT_URL);
+  linkedBrowser.messageManager.loadFrameScript(COMMON_FRAME_SCRIPT_URL, false);
+
   linkedBrowser.addEventListener("load", function onload() {
     linkedBrowser.removeEventListener("load", onload, true);
     info("URL '" + url + "' loading complete");
@@ -124,6 +128,50 @@ function openInspector() {
   return def.promise;
 }
 
+/**
+ * Wait for a content -> chrome message on the message manager (the window
+ * messagemanager is used).
+ * @param {String} name The message name
+ * @return {Promise} A promise that resolves to the response data when the
+ * message has been received
+ */
+function waitForContentMessage(name) {
+  info("Expecting message " + name + " from content");
+
+  let mm = gBrowser.selectedBrowser.messageManager;
+
+  let def = promise.defer();
+  mm.addMessageListener(name, function onMessage(msg) {
+    mm.removeMessageListener(name, onMessage);
+    def.resolve(msg.data);
+  });
+  return def.promise;
+}
+
+/**
+ * Send an async message to the frame script (chrome -> content) and wait for a
+ * response message with the same name (content -> chrome).
+ * @param {String} name The message name. Should be one of the messages defined
+ * in doc_frame_script.js
+ * @param {Object} data Optional data to send along
+ * @param {Object} objects Optional CPOW objects to send along
+ * @param {Boolean} expectResponse If set to false, don't wait for a response
+ * with the same name from the content script. Defaults to true.
+ * @return {Promise} Resolves to the response data if a response is expected,
+ * immediately resolves otherwise
+ */
+function executeInContent(name, data={}, objects={}, expectResponse=true) {
+  info("Sending message " + name + " to content");
+  let mm = gBrowser.selectedBrowser.messageManager;
+
+  mm.sendAsyncMessage(name, data, objects);
+  if (expectResponse) {
+    return waitForContentMessage(name);
+  } else {
+    return promise.resolve();
+  }
+}
+
 /**
  * Simple DOM node accesor function that takes either a node or a string css
  * selector as argument and returns the corresponding node

browser/devtools/shared/frame-script-utils.js

@@ -133,6 +133,36 @@ addMessageListener("devtools:test:setStyle", function(msg) {
   sendAsyncMessage("devtools:test:setStyle");
 });
 
+/**
+ * Get information about a DOM element, identified by a selector.
+ * @param {Object} data
+ * - {String} selector The CSS selector to get the node (can be a "super"
+ *   selector).
+ * @return {Object} data Null if selector didn't match any node, otherwise:
+ * - {String} tagName.
+ * - {String} namespaceURI.
+ * - {Number} numChildren The number of children in the element.
+ * - {Array} attributes An array of {name, value, namespaceURI} objects.
+ */
+addMessageListener("devtools:test:getDomElementInfo", function(msg) {
+  let {selector} = msg.data;
+  let node = superQuerySelector(selector);
+
+  let info = null;
+  if (node) {
+    info = {
+      tagName: node.tagName,
+      namespaceURI: node.namespaceURI,
+      numChildren: node.children.length,
+      attributes: [...node.attributes].map(({name, value, namespaceURI}) => {
+        return {name, value, namespaceURI};
+      })
+    };
+  }
+
+  sendAsyncMessage("devtools:test:getDomElementInfo", info);
+});
+
 /**
  * Set a given attribute value on a node.
  * @param {Object} data