diff -r 000000000000 -r 6474c204b198 browser/devtools/framework/test/browser_toolbox_sidebar.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/devtools/framework/test/browser_toolbox_sidebar.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,150 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+function test() {
+  const Cu = Components.utils;
+  let {ToolSidebar} = devtools.require("devtools/framework/sidebar");
+
+  const toolURL = "data:text/xml;charset=utf8,<?xml version='1.0'?>" +
+                  "<?xml-stylesheet href='chrome://browser/skin/devtools/common.css' type='text/css'?>" +
+                  "<window xmlns='http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul'>" +
+                  "<hbox flex='1'><description flex='1'>foo</description><splitter class='devtools-side-splitter'/>" +
+                  "<tabbox flex='1' id='sidebar' class='devtools-sidebar-tabs'><tabs/><tabpanels flex='1'/></tabbox>" +
+                  "</hbox>" +
+                  "</window>";
+
+  const tab1URL = "data:text/html;charset=utf8,<title>1</title><p>1</p>";
+  const tab2URL = "data:text/html;charset=utf8,<title>2</title><p>2</p>";
+  const tab3URL = "data:text/html;charset=utf8,<title>3</title><p>3</p>";
+
+  let panelDoc;
+  let tab1Selected = false;
+  let registeredTabs = {};
+  let readyTabs = {};
+
+  let toolDefinition = {
+    id: "fakeTool4242",
+    visibilityswitch: "devtools.fakeTool4242.enabled",
+    url: toolURL,
+    label: "FAKE TOOL!!!",
+    isTargetSupported: function() true,
+    build: function(iframeWindow, toolbox) {
+      let deferred = promise.defer();
+      executeSoon(function() {
+        deferred.resolve({
+          target: toolbox.target,
+          toolbox: toolbox,
+          isReady: true,
+          destroy: function(){},
+          panelDoc: iframeWindow.document,
+        });
+      }.bind(this));
+      return deferred.promise;
+    },
+  };
+
+  gDevTools.registerTool(toolDefinition);
+
+  addTab("about:blank", function(aBrowser, aTab) {
+    let target = TargetFactory.forTab(gBrowser.selectedTab);
+    gDevTools.showToolbox(target, toolDefinition.id).then(function(toolbox) {
+      let panel = toolbox.getPanel(toolDefinition.id);
+      ok(true, "Tool open");
+
+      let tabbox = panel.panelDoc.getElementById("sidebar");
+      panel.sidebar = new ToolSidebar(tabbox, panel, "testbug865688", true);
+
+      panel.sidebar.on("new-tab-registered", function(event, id) {
+        registeredTabs[id] = true;
+      });
+
+      panel.sidebar.once("tab1-ready", function(event) {
+        info(event);
+        readyTabs.tab1 = true;
+        allTabsReady(panel);
+      });
+
+      panel.sidebar.once("tab2-ready", function(event) {
+        info(event);
+        readyTabs.tab2 = true;
+        allTabsReady(panel);
+      });
+
+      panel.sidebar.once("tab3-ready", function(event) {
+        info(event);
+        readyTabs.tab3 = true;
+        allTabsReady(panel);
+      });
+
+      panel.sidebar.once("tab1-selected", function(event) {
+        info(event);
+        tab1Selected = true;
+        allTabsReady(panel);
+      });
+
+      panel.sidebar.addTab("tab1", tab1URL, true);
+      panel.sidebar.addTab("tab2", tab2URL);
+      panel.sidebar.addTab("tab3", tab3URL);
+
+      panel.sidebar.show();
+    }).then(null, console.error);
+  });
+
+  function allTabsReady(panel) {
+    if (!tab1Selected || !readyTabs.tab1 || !readyTabs.tab2 || !readyTabs.tab3) {
+      return;
+    }
+
+    ok(registeredTabs.tab1, "tab1 registered");
+    ok(registeredTabs.tab2, "tab2 registered");
+    ok(registeredTabs.tab3, "tab3 registered");
+    ok(readyTabs.tab1, "tab1 ready");
+    ok(readyTabs.tab2, "tab2 ready");
+    ok(readyTabs.tab3, "tab3 ready");
+
+    let tabs = panel.sidebar._tabbox.querySelectorAll("tab");
+    let panels = panel.sidebar._tabbox.querySelectorAll("tabpanel");
+    let label = 1;
+    for (let tab of tabs) {
+      is(tab.getAttribute("label"), label++, "Tab has the right title");
+    }
+    is(label, 4, "Found the right amount of tabs.");
+    is(panel.sidebar._tabbox.selectedPanel, panels[0], "First tab is selected");
+    ok(panel.sidebar.getCurrentTabID(), "tab1", "getCurrentTabID() is correct");
+
+    panel.sidebar.once("tab1-unselected", function() {
+      ok(true, "received 'unselected' event");
+      panel.sidebar.once("tab2-selected", function() {
+        ok(true, "received 'selected' event");
+        panel.sidebar.hide();
+        is(panel.sidebar._tabbox.getAttribute("hidden"), "true", "Sidebar hidden");
+        is(panel.sidebar.getWindowForTab("tab1").location.href, tab1URL, "Window is accessible");
+        testWidth(panel);
+      });
+    });
+
+    panel.sidebar.select("tab2");
+  }
+
+  function testWidth(panel) {
+    let tabbox = panel.panelDoc.getElementById("sidebar");
+    tabbox.width = 420;
+    panel.sidebar.destroy().then(function() {
+      tabbox.width = 0;
+      panel.sidebar = new ToolSidebar(tabbox, panel, "testbug865688", true);
+      panel.sidebar.show();
+      is(panel.panelDoc.getElementById("sidebar").width, 420, "Width restored")
+      finishUp(panel);
+    });
+  }
+
+  function finishUp(panel) {
+    panel.sidebar.destroy();
+    gDevTools.unregisterTool(toolDefinition.id);
+
+    executeSoon(function() {
+      gBrowser.removeCurrentTab();
+      finish();
+    });
+  }
+}