diff -r 000000000000 -r 6474c204b198 browser/devtools/styleinspector/test/browser_ruleview_edit-property-order.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/devtools/styleinspector/test/browser_ruleview_edit-property-order.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,68 @@
+/* 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/ */
+
+"use strict";
+
+// Checking properties orders and overrides in the rule-view
+
+let test = asyncTest(function*() {
+  yield addTab("data:text/html;charset=utf-8,browser_ruleview_manipulation.js");
+  let {toolbox, inspector, view} = yield openRuleView();
+
+  info("Creating the test document and getting the test node");
+  content.document.body.innerHTML = '<div id="testid">Styled Node</div>';
+  let element = getNode("#testid");
+
+  yield selectNode(element, inspector);
+
+  let elementStyle = view._elementStyle;
+  let elementRule = elementStyle.rules[0];
+
+  info("Checking rules insertion order and checking the applied style");
+  let firstProp = elementRule.createProperty("background-color", "green", "");
+  let secondProp = elementRule.createProperty("background-color", "blue", "");
+  is(elementRule.textProps[0], firstProp, "Rules should be in addition order.");
+  is(elementRule.textProps[1], secondProp, "Rules should be in addition order.");
+  yield elementRule._applyingModifications;
+  is(element.style.getPropertyValue("background-color"), "blue", "Second property should have been used.");
+
+  info("Removing the second property and checking the applied style again");
+  secondProp.remove();
+  yield elementRule._applyingModifications;
+  is(element.style.getPropertyValue("background-color"), "green", "After deleting second property, first should be used.");
+
+  info("Creating a new second property and checking that the insertion order is still the same");
+  secondProp = elementRule.createProperty("background-color", "blue", "");
+  yield elementRule._applyingModifications;
+  is(element.style.getPropertyValue("background-color"), "blue", "New property should be used.");
+  is(elementRule.textProps[0], firstProp, "Rules shouldn't have switched places.");
+  is(elementRule.textProps[1], secondProp, "Rules shouldn't have switched places.");
+
+  info("Disabling the second property and checking the applied style");
+  secondProp.setEnabled(false);
+  yield elementRule._applyingModifications;
+  is(element.style.getPropertyValue("background-color"), "green", "After disabling second property, first value should be used");
+
+  info("Disabling the first property too and checking the applied style");
+  firstProp.setEnabled(false);
+  yield elementRule._applyingModifications;
+  is(element.style.getPropertyValue("background-color"), "", "After disabling both properties, value should be empty.");
+
+  info("Re-enabling the second propertyt and checking the applied style");
+  secondProp.setEnabled(true);
+  yield elementRule._applyingModifications;
+  is(element.style.getPropertyValue("background-color"), "blue", "Value should be set correctly after re-enabling");
+
+  info("Re-enabling the first property and checking the insertion order is still respected");
+  firstProp.setEnabled(true);
+  yield elementRule._applyingModifications;
+  is(element.style.getPropertyValue("background-color"), "blue", "Re-enabling an earlier property shouldn't make it override a later property.");
+  is(elementRule.textProps[0], firstProp, "Rules shouldn't have switched places.");
+  is(elementRule.textProps[1], secondProp, "Rules shouldn't have switched places.");
+
+  info("Modifying the first property and checking the applied style");
+  firstProp.setValue("purple", "");
+  yield elementRule._applyingModifications;
+  is(element.style.getPropertyValue("background-color"), "blue", "Modifying an earlier property shouldn't override a later property.");
+});