diff -r 000000000000 -r 6474c204b198 browser/devtools/netmonitor/test/browser_net_prefs-and-l10n.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/devtools/netmonitor/test/browser_net_prefs-and-l10n.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,67 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Tests if the preferences and localization objects work correctly.
+ */
+
+function test() {
+  initNetMonitor(SIMPLE_URL).then(([aTab, aDebuggee, aMonitor]) => {
+    info("Starting test... ");
+
+    ok(aMonitor.panelWin.L10N,
+      "Should have a localization object available on the panel window.");
+    ok(aMonitor.panelWin.Prefs,
+      "Should have a preferences object available on the panel window.");
+
+    function testL10N() {
+      let { L10N } = aMonitor.panelWin;
+
+      ok(L10N.stringBundle,
+        "The localization object should have a string bundle available.");
+
+      let bundleName = "chrome://browser/locale/devtools/netmonitor.properties";
+      let stringBundle = Services.strings.createBundle(bundleName);
+
+      is(L10N.getStr("netmonitor.label"),
+        stringBundle.GetStringFromName("netmonitor.label"),
+        "The getStr() method didn't return the expected string.");
+
+      is(L10N.getFormatStr("networkMenu.totalMS", "foo"),
+        stringBundle.formatStringFromName("networkMenu.totalMS", ["foo"], 1),
+        "The getFormatStr() method didn't return the expected string.");
+    }
+
+    function testPrefs() {
+      let { Prefs } = aMonitor.panelWin;
+
+      is(Prefs.root, "devtools.netmonitor",
+        "The preferences object should have a correct root path.");
+
+      is(Prefs.networkDetailsWidth,
+        Services.prefs.getIntPref("devtools.netmonitor.panes-network-details-width"),
+        "Getting a pref should work correctly.");
+
+      let previousValue = Prefs.networkDetailsWidth;
+      let bogusValue = ~~(Math.random() * 100);
+      Prefs.networkDetailsWidth = bogusValue;
+      is(Prefs.networkDetailsWidth,
+        Services.prefs.getIntPref("devtools.netmonitor.panes-network-details-width"),
+        "Getting a pref after it has been modified should work correctly.");
+      is(Prefs.networkDetailsWidth, bogusValue,
+        "The pref wasn't updated correctly in the preferences object.");
+
+      Prefs.networkDetailsWidth = previousValue;
+      is(Prefs.networkDetailsWidth,
+        Services.prefs.getIntPref("devtools.netmonitor.panes-network-details-width"),
+        "Getting a pref after it has been modified again should work correctly.");
+      is(Prefs.networkDetailsWidth, previousValue,
+        "The pref wasn't updated correctly again in the preferences object.");
+    }
+
+    testL10N();
+    testPrefs();
+
+    teardown(aMonitor).then(finish);
+  });
+}