1 files changed, 46 insertions, 0 deletions
diff --git a/devtools/client/inspector/changes/test/browser_changes_background_tracking.js b/devtools/client/inspector/changes/test/browser_changes_background_tracking.js
new file mode 100644
index 0000000000..613e2d9062
--- /dev/null
+++ b/devtools/client/inspector/changes/test/browser_changes_background_tracking.js
@@ -0,0 +1,46 @@
+/* Any copyright is dedicated to the Public Domain.
+ http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test that CSS changes are collected in the background without the Changes panel visible
+
+const TEST_URI = `
+  <style type='text/css'>
+    div {
+      color: red;
+    }
+  </style>
+  <div></div>
+`;
+
+add_task(async function () {
+  info("Ensure Changes panel is NOT the default panel; use Computed panel");
+  await pushPref("devtools.inspector.activeSidebar", "computedview");
+
+  await addTab("data:text/html;charset=utf-8," + encodeURIComponent(TEST_URI));
+  const { inspector, view: ruleView } = await openRuleView();
+
+  await selectNode("div", inspector);
+  const prop = getTextProperty(ruleView, 1, { color: "red" });
+
+  info("Disable the first CSS declaration");
+  await togglePropStatus(ruleView, prop);
+
+  info("Select the Changes panel");
+  const { document: doc, store } = selectChangesView(inspector);
+  const onTrackChange = waitForDispatch(store, "TRACK_CHANGE");
+  const onResetChanges = waitForDispatch(store, "RESET_CHANGES");
+
+  info("Wait for change to be tracked");
+  await onTrackChange;
+  const removedDeclarations = getRemovedDeclarations(doc);
+  is(removedDeclarations.length, 1, "One declaration was tracked as removed");
+
+  // Test for Bug 1656477. Check that changes are not cleared immediately afterwards.
+  info("Wait to see if the RESET_CHANGES action is dispatched unexpecteldy");
+  const sym = Symbol();
+  const onTimeout = wait(500).then(() => sym);
+  const raceResult = await Promise.any([onResetChanges, onTimeout]);
+  ok(raceResult === sym, "RESET_CHANGES has not been dispatched");
+});