Bug 1192421 - Part 3: Add a test. r=pbrosset

browser/devtools/styleinspector/test/browser.ini

@@ -143,6 +143,7 @@ skip-if = (os == "win" && debug) || e10s # bug 963492: win. bug 1040653: e10s.
 [browser_ruleview_pseudo-element_02.js]
 skip-if = e10s # Bug 1090340
 [browser_ruleview_pseudo_lock_options.js]
+[browser_ruleview_refresh-noflicker.js]
 [browser_ruleview_refresh-on-attribute-change_01.js]
 [browser_ruleview_refresh-on-attribute-change_02.js]
 [browser_ruleview_refresh-on-style-change.js]

browser/devtools/styleinspector/test/browser_ruleview_refresh-noflicker.js

@@ -0,0 +1,33 @@
+/* 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";
+
+// Test that the rule view does not go blank while selecting a new node.
+
+const TESTCASE_URI = 'data:text/html;charset=utf-8,' +
+                     '<div id="testdiv" style="font-size:10px;">Test div!</div>';
+
+add_task(function*() {
+  yield addTab(TESTCASE_URI);
+
+  info("Opening the rule view and selecting the test node");
+  let {toolbox, inspector, view} = yield openRuleView();
+  let testdiv = yield getNodeFront("#testdiv", inspector);
+  yield selectNode(testdiv, inspector);
+
+  let htmlBefore = view.element.innerHTML;
+  ok(htmlBefore.indexOf("font-size") > -1, "The rule view should contain a font-size property.");
+
+  // Do the selectNode call manually, because otherwise it's hard to guarantee
+  // that we can make the below checks at a reasonable time.
+  info("refreshing the node");
+  let p = view.selectElement(testdiv, true);
+  is(view.element.innerHTML, htmlBefore, "The rule view is unchanged during selection.");
+  ok(view.element.classList.contains("non-interactive"), "The rule view is marked non-interactive.");
+  yield p;
+
+  info("node refreshed");
+  ok(!view.element.classList.contains("non-interactive"), "The rule view is marked interactive again.");
+});