diff -r 000000000000 -r 6474c204b198 browser/devtools/netmonitor/test/browser_net_charts-02.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/devtools/netmonitor/test/browser_net_charts-02.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,49 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Makes sure Pie Charts have the right internal structure when
+ * initialized with empty data.
+ */
+
+function test() {
+  initNetMonitor(SIMPLE_URL).then(([aTab, aDebuggee, aMonitor]) => {
+    info("Starting test... ");
+
+    let { document, L10N, Chart } = aMonitor.panelWin;
+    let container = document.createElement("box");
+
+    let pie = Chart.Pie(document, {
+      data: null,
+      width: 100,
+      height: 100
+    });
+
+    let node = pie.node;
+    let slices = node.querySelectorAll(".pie-chart-slice.chart-colored-blob");
+    let labels = node.querySelectorAll(".pie-chart-label");
+
+    ok(node.classList.contains("pie-chart-container") &&
+       node.classList.contains("generic-chart-container"),
+      "A pie chart container was created successfully.");
+
+    is(slices.length, 1,
+      "There should be 1 pie chart slice created.");
+    ok(slices[0].getAttribute("d").match(/\s*M 50,50 L 50\.\d+,2\.5\d* A 47\.5,47\.5 0 1 1 49\.\d+,2\.5\d* Z/),
+      "The first slice has the correct data.");
+
+    ok(slices[0].hasAttribute("largest"),
+      "The first slice should be the largest one.");
+    ok(slices[0].hasAttribute("smallest"),
+      "The first slice should also be the smallest one.");
+    ok(slices[0].getAttribute("name"), L10N.getStr("pieChart.loading"),
+      "The first slice's name is correct.");
+
+    is(labels.length, 1,
+      "There should be 1 pie chart label created.");
+    is(labels[0].textContent, "Loading",
+      "The first label's text is correct.");
+
+    teardown(aMonitor).then(finish);
+  });
+}