1 files changed, 53 insertions, 0 deletions
diff --git a/devtools/client/inspector/changes/test/browser_changes_declaration_remove_ahead.js b/devtools/client/inspector/changes/test/browser_changes_declaration_remove_ahead.js
new file mode 100644
index 0000000000..b249fc8198
--- /dev/null
+++ b/devtools/client/inspector/changes/test/browser_changes_declaration_remove_ahead.js
@@ -0,0 +1,53 @@
+/* Any copyright is dedicated to the Public Domain.
+ http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test that the correct declaration is identified and changed after removing a
+// declaration positioned ahead of it in the same CSS rule.
+
+const TEST_URI = `
+  <style type='text/css'>
+    div {
+      color: red;
+      display: block;
+    }
+  </style>
+  <div></div>
+`;
+
+add_task(async function () {
+  await addTab("data:text/html;charset=utf-8," + encodeURIComponent(TEST_URI));
+  const { inspector, view: ruleView } = await openRuleView();
+  const { document: doc, store } = selectChangesView(inspector);
+
+  await selectNode("div", inspector);
+  const prop1 = getTextProperty(ruleView, 1, { color: "red" });
+  const prop2 = getTextProperty(ruleView, 1, { display: "block" });
+
+  let onTrackChange = waitForDispatch(store, "TRACK_CHANGE");
+  info("Change the second declaration");
+  await setProperty(ruleView, prop2, "grid");
+  await onTrackChange;
+
+  onTrackChange = waitForDispatch(store, "TRACK_CHANGE");
+  info("Remove the first declaration");
+  await removeProperty(ruleView, prop1);
+  await onTrackChange;
+
+  onTrackChange = waitForDispatch(store, "TRACK_CHANGE");
+  info("Change the second declaration again");
+  await setProperty(ruleView, prop2, "flex");
+  info("Wait for change to be tracked");
+  await onTrackChange;
+
+  // Ensure changes to the second declaration were tracked after removing the first one.
+  await waitFor(
+    () => getRemovedDeclarations(doc).length == 2,
+    "Two declarations should have been tracked as removed"
+  );
+  await waitFor(() => {
+    const addDecl = getAddedDeclarations(doc);
+    return addDecl.length == 1 && addDecl[0].value == "flex";
+  }, "One declaration should have been tracked as added, and the added declaration to have updated property value");
+});