diff -r 000000000000 -r 6474c204b198 browser/devtools/inspector/test/browser_inspector_breadcrumbs.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/devtools/inspector/test/browser_inspector_breadcrumbs.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,101 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+function test()
+{
+  waitForExplicitFinish();
+  ignoreAllUncaughtExceptions();
+
+  let nodes = [
+    {nodeId: "i1111", result: "i1 i11 i111 i1111"},
+    {nodeId: "i22", result: "i2 i22 i221"},
+    {nodeId: "i2111", result: "i2 i21 i211 i2111"},
+    {nodeId: "i21", result: "i2 i21 i211 i2111"},
+    {nodeId: "i22211", result: "i2 i22 i222 i2221 i22211"},
+    {nodeId: "i22", result: "i2 i22 i222 i2221 i22211"},
+  ];
+
+  let doc;
+  let nodes;
+  let cursor;
+  let inspector;
+  let target;
+  let panel;
+  let container;
+
+  gBrowser.selectedTab = gBrowser.addTab();
+  gBrowser.selectedBrowser.addEventListener("load", function onload() {
+    gBrowser.selectedBrowser.removeEventListener("load", onload, true);
+    doc = content.document;
+    waitForFocus(setupTest, content);
+  }, true);
+
+  content.location = "http://mochi.test:8888/browser/browser/devtools/inspector/test/browser_inspector_breadcrumbs.html";
+
+  function setupTest()
+  {
+    for (let i = 0; i < nodes.length; i++) {
+      let node = doc.getElementById(nodes[i].nodeId);
+      nodes[i].node = node;
+      ok(nodes[i].node, "node " + nodes[i].nodeId + " found");
+    }
+
+    openInspector(runTests);
+  }
+
+  function runTests(aInspector)
+  {
+    inspector = aInspector;
+    target = TargetFactory.forTab(gBrowser.selectedTab);
+    panel = gDevTools.getToolbox(target).getPanel("inspector");
+    container = panel.panelDoc.getElementById("inspector-breadcrumbs");
+    cursor = 0;
+    inspector.on("breadcrumbs-updated", nodeSelected);
+    executeSoon(function() {
+      inspector.selection.setNode(nodes[0].node);
+    });
+  }
+
+  function nodeSelected()
+  {
+    performTest();
+    cursor++;
+
+    if (cursor >= nodes.length) {
+      inspector.off("breadcrumbs-updated", nodeSelected);
+      // breadcrumbs-updated is an event that is fired before the rest of the
+      // inspector is updated, so there'll be hanging connections if we finish
+      // up before waiting for everything to end.
+      inspector.once("inspector-updated", finishUp);
+    } else {
+      let node = nodes[cursor].node;
+      inspector.selection.setNode(node);
+    }
+  }
+
+  function performTest()
+  {
+    let buttonsLabelIds = nodes[cursor].result.split(" ");
+
+    // html > body > …
+    is(container.childNodes.length, buttonsLabelIds.length + 2, "Node " + cursor + ": Items count");
+
+    for (let i = 2; i < container.childNodes.length; i++) {
+      let expectedId = "#" + buttonsLabelIds[i - 2];
+      let button = container.childNodes[i];
+      let labelId = button.querySelector(".breadcrumbs-widget-item-id");
+      is(labelId.textContent, expectedId, "Node " + cursor + ": button " + i + " matches");
+    }
+
+    let checkedButton = container.querySelector("button[checked]");
+    let labelId = checkedButton.querySelector(".breadcrumbs-widget-item-id");
+    let id = inspector.selection.node.id;
+    is(labelId.textContent, "#" + id, "Node " + cursor + ": selection matches");
+  }
+
+  function finishUp() {
+    doc = nodes = inspector = null;
+    gBrowser.removeCurrentTab();
+    finish();
+  }
+}