Bug 659625 - part2: implement console.clear in devtools webconsole;r=bgrins

When receiving a console clear message, the webconsole should clear
the UI: remove all messages until the clear() message and close
the variables view sidebar if opened.

Add one integration tests to test console.clear calls from the content page.

MozReview-Commit-ID: GnBCBSmN1rk

--HG--
extra : rebase_source : 3bb9f99fa4ac8ed6772e325dba978ce3e6a0f202
extra : source : 671011b82100a598dd8368205bd625227bfdc060

devtools/client/locales/en-US/webconsole.properties

@@ -107,6 +107,11 @@ timerStarted=%S: timer started
 # is the number of milliseconds.
 timeEnd=%1$S: %2$Sms
 
+# LOCALIZATION NOTE (consoleCleared): this string is displayed when receiving a
+# call to console.clear() to let the user know the previous messages of the
+# console have been removed programmatically.
+consoleCleared=Console was cleared.
+
 # LOCALIZATION NOTE (noCounterLabel): this string is used to display
 # count-messages with no label provided.
 noCounterLabel=<no label>

devtools/client/webconsole/console-output.js

@@ -93,6 +93,7 @@ const CONSOLE_API_LEVELS_TO_SEVERITIES = {
   warn: "warning",
   info: "info",
   log: "log",
+  clear: "log",
   trace: "log",
   table: "log",
   debug: "log",

devtools/client/webconsole/test/browser.ini

@@ -69,6 +69,7 @@ support-files =
   test-closure-optimized-out.html
   test-closures.html
   test-console-assert.html
+  test-console-clear.html
   test-console-count.html
   test-console-count-external-file.js
   test-console-extras.html
@@ -157,6 +158,7 @@ skip-if = (e10s && (os == 'win' || os == 'mac')) # Bug 1243976
 [browser_cached_messages.js]
 [browser_console.js]
 [browser_console_addonsdk_loader_exception.js]
+[browser_console_clear_method.js]
 [browser_console_clear_on_reload.js]
 [browser_console_click_focus.js]
 [browser_console_consolejsm_output.js]

devtools/client/webconsole/test/browser_console_clear_method.js

@@ -0,0 +1,131 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Check that calls to console.clear from a script delete the messages
+// previously logged.
+
+"use strict";
+
+add_task(function* () {
+  const TEST_URI = "http://example.com/browser/devtools/client/webconsole/" +
+                   "test/test-console-clear.html";
+
+  yield loadTab(TEST_URI);
+  let hud = yield openConsole();
+  ok(hud, "Web Console opened");
+
+  info("Check the console.clear() done on page load has been processed.");
+  yield waitForLog("Console was cleared", hud);
+  ok(hud.outputNode.textContent.includes("Console was cleared"),
+    "console.clear() message is displayed");
+  ok(!hud.outputNode.textContent.includes("log1"), "log1 not displayed");
+  ok(!hud.outputNode.textContent.includes("log2"), "log2 not displayed");
+
+  info("Logging two messages log3, log4");
+  ContentTask.spawn(gBrowser.selectedBrowser, {}, function* () {
+    content.wrappedJSObject.console.log("log3");
+    content.wrappedJSObject.console.log("log4");
+  });
+
+  yield waitForLog("log3", hud);
+  yield waitForLog("log4", hud);
+
+  ok(hud.outputNode.textContent.includes("Console was cleared"),
+    "console.clear() message is still displayed");
+  ok(hud.outputNode.textContent.includes("log3"), "log3 is displayed");
+  ok(hud.outputNode.textContent.includes("log4"), "log4 is displayed");
+
+  info("Open the variables view sidebar for 'objFromPage'");
+  yield openSidebar("objFromPage", { a: 1 }, hud);
+  let sidebarClosed = hud.jsterm.once("sidebar-closed");
+
+  info("Call console.clear from the page");
+  ContentTask.spawn(gBrowser.selectedBrowser, {}, function* () {
+    content.wrappedJSObject.console.clear();
+  });
+
+  // Cannot wait for "Console was cleared" here because such a message is
+  // already present and would yield immediately.
+  info("Wait for variables view sidebar to be closed after console.clear()");
+  yield sidebarClosed;
+
+  ok(!hud.outputNode.textContent.includes("log3"), "log3 not displayed");
+  ok(!hud.outputNode.textContent.includes("log4"), "log4 not displayed");
+  ok(hud.outputNode.textContent.includes("Console was cleared"),
+    "console.clear() message is still displayed");
+  is(hud.outputNode.textContent.split("Console was cleared").length, 2,
+    "console.clear() message is only displayed once");
+
+  info("Logging one messages log5");
+  ContentTask.spawn(gBrowser.selectedBrowser, {}, function* () {
+    content.wrappedJSObject.console.log("log5");
+  });
+  yield waitForLog("log5", hud);
+
+  info("Close and reopen the webconsole.");
+  yield closeConsole(gBrowser.selectedTab);
+  hud = yield openConsole();
+  yield waitForLog("Console was cleared", hud);
+
+  ok(hud.outputNode.textContent.includes("Console was cleared"),
+    "console.clear() message is still displayed");
+  ok(!hud.outputNode.textContent.includes("log1"), "log1 not displayed");
+  ok(!hud.outputNode.textContent.includes("log2"), "log1 not displayed");
+  ok(!hud.outputNode.textContent.includes("log3"), "log3 not displayed");
+  ok(!hud.outputNode.textContent.includes("log4"), "log4 not displayed");
+  ok(hud.outputNode.textContent.includes("log5"), "log5 still displayed");
+});
+
+/**
+ * Wait for a single message to be logged in the provided webconsole instance
+ * with the category CATEGORY_WEBDEV and the SEVERITY_LOG severity.
+ *
+ * @param {String} message
+ *        The expected messaged.
+ * @param {WebConsole} webconsole
+ *        WebConsole instance in which the message should be logged.
+ */
+function* waitForLog(message, webconsole, options) {
+  yield waitForMessages({
+    webconsole: webconsole,
+    messages: [{
+      text: message,
+      category: CATEGORY_WEBDEV,
+      severity: SEVERITY_LOG,
+    }],
+  });
+}
+
+/**
+ * Open the variables view sidebar for the object with the provided name objName
+ * and wait for the expected object is displayed in the variables view.
+ *
+ * @param {String} objName
+ *        The name of the object to open in the sidebar.
+ * @param {Object} expectedObj
+ *        The properties that should be displayed in the variables view.
+ * @param {WebConsole} webconsole
+ *        WebConsole instance in which the message should be logged.
+ *
+ */
+function* openSidebar(objName, expectedObj, webconsole) {
+  let msg = yield webconsole.jsterm.execute(objName);
+  ok(msg, "output message found");
+
+  let anchor = msg.querySelector("a");
+  let body = msg.querySelector(".message-body");
+  ok(anchor, "object anchor");
+  ok(body, "message body");
+
+  yield EventUtils.synthesizeMouse(anchor, 2, 2, {}, webconsole.iframeWindow);
+
+  let vviewVar = yield webconsole.jsterm.once("variablesview-fetched");
+  let vview = vviewVar._variablesView;
+  ok(vview, "variables view object exists");
+
+  yield findVariableViewProperties(vviewVar, [
+    expectedObj,
+  ], { webconsole: webconsole });
+}

devtools/client/webconsole/test/test-console-clear.html

@@ -0,0 +1,16 @@
+<!DOCTYPE HTML>
+<html dir="ltr" xml:lang="en-US" lang="en-US"><head>
+    <meta charset="utf-8">
+    <title>Console.clear() tests</title>
+    <script type="text/javascript">
+      console.log("log1");
+      console.log("log2");
+      console.clear();
+
+      window.objFromPage = { a: 1 };
+    </script>
+  </head>
+  <body>
+    <h1 id="header">Clear Demo</h1>
+  </body>
+</html>

devtools/client/webconsole/webconsole.js

@@ -142,6 +142,7 @@ const LEVELS = {
   warn: SEVERITY_WARNING,
   info: SEVERITY_INFO,
   log: SEVERITY_LOG,
+  clear: SEVERITY_LOG,
   trace: SEVERITY_LOG,
   table: SEVERITY_LOG,
   debug: SEVERITY_LOG,
@@ -1285,6 +1286,11 @@ WebConsoleFrame.prototype = {
         node = msg.init(this.output).render().element;
         break;
       }
+      case "clear": {
+        body = l10n.getStr("consoleCleared");
+        clipboardText = body;
+        break;
+      }
       case "dir": {
         body = { arguments: args };
         let clipboardArray = [];
@@ -2203,6 +2209,14 @@ WebConsoleFrame.prototype = {
 
     let isRepeated = this._filterRepeatedMessage(node);
 
+    // If a clear message is processed while the webconsole is opened, the UI
+    // should be cleared.
+    if (message && message.level == "clear") {
+      // Do not clear the consoleStorage here as it has been cleared already
+      // by the clear method, only clear the UI.
+      this.jsterm.clearOutput(false);
+    }
+
     let visible = !isRepeated && !isFiltered;
     if (!isRepeated) {
       this.outputNode.appendChild(node);