1 files changed, 111 insertions, 0 deletions
diff --git a/devtools/client/inspector/markup/test/browser_markup_dragdrop_reorder.js b/devtools/client/inspector/markup/test/browser_markup_dragdrop_reorder.js
new file mode 100644
index 0000000000..cbcc86fa74
--- /dev/null
+++ b/devtools/client/inspector/markup/test/browser_markup_dragdrop_reorder.js
@@ -0,0 +1,111 @@
+/* Any copyright is dedicated to the Public Domain.
+ http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+requestLongerTimeout(2);
+
+// Test different kinds of drag and drop node re-ordering.
+
+const TEST_URL = URL_ROOT + "doc_markup_dragdrop.html";
+
+add_task(async function () {
+  const { inspector } = await openInspectorForURL(TEST_URL);
+  let ids;
+
+  info("Expand #test node");
+  const parentFront = await getNodeFront("#test", inspector);
+  await inspector.markup.expandNode(parentFront);
+  await waitForMultipleChildrenUpdates(inspector);
+
+  info("Scroll #test into view");
+  const parentContainer = await getContainerForNodeFront(
+    parentFront,
+    inspector
+  );
+  parentContainer.elt.scrollIntoView(true);
+
+  info("Test putting an element back at its original place");
+  await dragElementToOriginalLocation("#firstChild", inspector);
+  ids = await getChildrenIDsOf(parentFront, inspector);
+  is(ids[0], "firstChild", "#firstChild is still the first child of #test");
+  is(ids[1], "middleChild", "#middleChild is still the second child of #test");
+
+  info("Testing switching elements inside their parent");
+  await moveElementDown("#firstChild", "#middleChild", inspector);
+  ids = await getChildrenIDsOf(parentFront, inspector);
+  is(ids[0], "middleChild", "#firstChild is now the second child of #test");
+  is(ids[1], "firstChild", "#middleChild is now the first child of #test");
+
+  info("Testing switching elements with a last child");
+  await moveElementDown("#firstChild", "#lastChild", inspector);
+  ids = await getChildrenIDsOf(parentFront, inspector);
+  is(ids[1], "lastChild", "#lastChild is now the second child of #test");
+  is(ids[2], "firstChild", "#firstChild is now the last child of #test");
+
+  info("Testing appending element to a parent");
+  await moveElementDown("#before", "#test", inspector);
+  ids = await getChildrenIDsOf(parentFront, inspector);
+  is(ids.length, 4, "New element appended to #test");
+  is(
+    ids[0],
+    "before",
+    "New element is appended at the right place (currently first child)"
+  );
+
+  info("Testing moving element to after it's parent");
+  await moveElementDown("#firstChild", "#test", inspector);
+  ids = await getChildrenIDsOf(parentFront, inspector);
+  is(ids.length, 3, "#firstChild is no longer #test's child");
+  const siblingFront = await inspector.walker.nextSibling(parentFront);
+  is(
+    siblingFront.id,
+    "firstChild",
+    "#firstChild is now #test's nextElementSibling"
+  );
+});
+
+async function dragElementToOriginalLocation(selector, inspector) {
+  info("Picking up and putting back down " + selector);
+
+  function onMutation() {
+    ok(false, "Mutation received from dragging a node back to its location");
+  }
+  inspector.on("markupmutation", onMutation);
+  await simulateNodeDragAndDrop(inspector, selector, 0, 0);
+
+  // Wait a bit to make sure the event never fires.
+  // This doesn't need to catch *all* cases, since the mutation
+  // will cause failure later in the test when it checks element ordering.
+  await wait(500);
+  inspector.off("markupmutation", onMutation);
+}
+
+async function moveElementDown(selector, next, inspector) {
+  info("Switching " + selector + " with " + next);
+
+  const container = await getContainerForSelector(next, inspector);
+  const height = container.tagLine.getBoundingClientRect().height;
+
+  const onMutated = inspector.once("markupmutation");
+  const uiUpdate = inspector.once("inspector-updated");
+
+  await simulateNodeDragAndDrop(inspector, selector, 0, Math.round(height) + 2);
+
+  const mutations = await onMutated;
+  await uiUpdate;
+
+  is(mutations.length, 2, "2 mutations were received");
+}
+
+async function getChildrenIDsOf(parentFront, { walker }) {
+  const { nodes } = await walker.children(parentFront);
+  // Filter out non-element nodes since children also returns pseudo-elements.
+  return nodes
+    .filter(node => {
+      return !node.isPseudoElement;
+    })
+    .map(node => {
+      return node.id;
+    });
+}