1 files changed, 54 insertions, 0 deletions
diff --git a/devtools/client/inspector/flexbox/test/browser_flexbox_container_and_item_updates_on_change.js b/devtools/client/inspector/flexbox/test/browser_flexbox_container_and_item_updates_on_change.js
new file mode 100644
index 0000000000..af62ac2ff0
--- /dev/null
+++ b/devtools/client/inspector/flexbox/test/browser_flexbox_container_and_item_updates_on_change.js
@@ -0,0 +1,54 @@
+/* Any copyright is dedicated to the Public Domain.
+ http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test that the flex container accordion is rendered when a flex item is updated to
+// also be a flex container.
+
+const TEST_URI = `
+  <style>
+    .container {
+      display: flex;
+    }
+  </style>
+  <div id="container" class="container">
+    <div id="item">
+      <div></div>
+    </div>
+  </div>
+`;
+
+add_task(async function () {
+  await addTab("data:text/html;charset=utf-8," + encodeURIComponent(TEST_URI));
+  const { inspector, flexboxInspector } = await openLayoutView();
+  const { document: doc } = flexboxInspector;
+
+  const onFlexItemSizingRendered = waitForDOM(doc, "ul.flex-item-sizing");
+  await selectNode("#item", inspector);
+  const [flexSizingContainer] = await onFlexItemSizingRendered;
+
+  ok(flexSizingContainer, "The flex sizing info is rendered.");
+
+  info("Changing the flexbox in the page.");
+  const onAccordionsChanged = waitForDOM(doc, ".accordion-item", 4);
+  await SpecialPowers.spawn(
+    gBrowser.selectedBrowser,
+    [],
+    () => (content.document.getElementById("item").className = "container")
+  );
+  const [flexItemPane, flexContainerPane] = await onAccordionsChanged;
+
+  ok(flexItemPane, "The flex item accordion pane is rendered.");
+  ok(flexContainerPane, "The flex container accordion pane is rendered.");
+  is(
+    flexItemPane.children[0].textContent,
+    "Flex Item of div#container.container",
+    "Got the correct header for the flex item pane."
+  );
+  is(
+    flexContainerPane.children[0].textContent,
+    "Flex Container",
+    "Got the correct header for the flex container pane."
+  );
+});