1 files changed, 157 insertions, 0 deletions
diff --git a/devtools/server/tests/browser/browser_inspector-retain.js b/devtools/server/tests/browser/browser_inspector-retain.js
new file mode 100644
index 0000000000..43d156675e
--- /dev/null
+++ b/devtools/server/tests/browser/browser_inspector-retain.js
@@ -0,0 +1,157 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+Services.scriptloader.loadSubScript(
+  "chrome://mochitests/content/browser/devtools/server/tests/browser/inspector-helpers.js",
+  this
+);
+
+// Retain a node, and a second-order child (in another document, for kicks)
+// Release the parent of the top item, which should cause one retained orphan.
+
+// Then unretain the top node, which should retain the orphan.
+
+// Then change the source of the iframe, which should kill that orphan.
+
+add_task(async function testRetain() {
+  // The test does not make sense when EFT is enabled, as different documents will have
+  // different walkers.
+  if (isEveryFrameTargetEnabled()) {
+    return;
+  }
+
+  const { walker } = await initInspectorFront(
+    MAIN_DOMAIN + "inspector-traversal-data.html"
+  );
+
+  // Get the toplevel body element and retain it.
+  const bodyFront = await walker.querySelector(walker.rootNode, "body");
+  await walker.retainNode(bodyFront);
+  // Get an element in the child frame and retain it.
+  const frame = await walker.querySelector(walker.rootNode, "#childFrame");
+  const children = await walker.children(frame, { maxNodes: 1 });
+  const childDoc = children.nodes[0];
+  const childListFront = await walker.querySelector(childDoc, "#longlist");
+  const originalOwnershipSize = await assertOwnershipTrees(walker);
+  // and retain it.
+  await walker.retainNode(childListFront);
+  // OK, try releasing the parent of the first retained.
+  await walker.releaseNode(bodyFront.parentNode());
+  const clientTree = clientOwnershipTree(walker);
+
+  // That request should have freed the parent of the first retained
+  // but moved the rest into the retained orphaned tree.
+  is(
+    ownershipTreeSize(clientTree.root) +
+      ownershipTreeSize(clientTree.retained[0]) +
+      1,
+    originalOwnershipSize,
+    "Should have only lost one item overall."
+  );
+  is(walker._retainedOrphans.size, 1, "Should have retained one orphan");
+  ok(
+    walker._retainedOrphans.has(bodyFront),
+    "Should have retained the expected node."
+  );
+  // Unretain the body, which should promote the childListFront to a retained orphan.
+  await walker.unretainNode(bodyFront);
+  await assertOwnershipTrees(walker);
+
+  is(
+    walker._retainedOrphans.size,
+    1,
+    "Should still only have one retained orphan."
+  );
+  ok(
+    !walker._retainedOrphans.has(bodyFront),
+    "Should have dropped the body node."
+  );
+  ok(
+    walker._retainedOrphans.has(childListFront),
+    "Should have retained the child node."
+  );
+
+  // Change the source of the iframe, which should kill the retained orphan.
+  const onMutations = waitForMutation(walker, isUnretained);
+  await SpecialPowers.spawn(gBrowser.selectedBrowser, [], function () {
+    content.document.querySelector("#childFrame").src =
+      "data:text/html,<html>new child</html>";
+  });
+  await onMutations;
+
+  await assertOwnershipTrees(walker);
+  is(walker._retainedOrphans.size, 0, "Should have no more retained orphans.");
+});
+
+// Get a hold of a node, remove it from the doc and retain it at the same time.
+// We should always win that race (even though the mutation happens before the
+// retain request), because we haven't issued `getMutations` yet.
+add_task(async function testWinRace() {
+  const { walker } = await initInspectorFront(
+    MAIN_DOMAIN + "inspector-traversal-data.html"
+  );
+
+  const front = await walker.querySelector(walker.rootNode, "#a");
+  const onMutation = waitForMutation(walker, isChildList);
+  SpecialPowers.spawn(gBrowser.selectedBrowser, [], function () {
+    const contentNode = content.document.querySelector("#a");
+    contentNode.remove();
+  });
+  // Now wait for that mutation and retain response to come in.
+  await walker.retainNode(front);
+  await onMutation;
+
+  await assertOwnershipTrees(walker);
+  is(walker._retainedOrphans.size, 1, "Should have a retained orphan.");
+  ok(
+    walker._retainedOrphans.has(front),
+    "Should have retained our expected node."
+  );
+  await walker.unretainNode(front);
+
+  // Make sure we're clear for the next test.
+  await assertOwnershipTrees(walker);
+  is(walker._retainedOrphans.size, 0, "Should have no more retained orphans.");
+});
+
+// Same as above, but issue the request right after the 'new-mutations' event, so that
+// we *lose* the race.
+add_task(async function testLoseRace() {
+  const { walker } = await initInspectorFront(
+    MAIN_DOMAIN + "inspector-traversal-data.html"
+  );
+
+  const front = await walker.querySelector(walker.rootNode, "#z");
+  const onMutation = walker.once("new-mutations");
+  await SpecialPowers.spawn(gBrowser.selectedBrowser, [], function () {
+    const contentNode = content.document.querySelector("#z");
+    contentNode.remove();
+  });
+  await onMutation;
+
+  // Verify that we have an outstanding request (no good way to tell that it's a
+  // getMutations request, but there's nothing else it would be).
+  is(walker._requests.length, 1, "Should have an outstanding request.");
+  try {
+    await walker.retainNode(front);
+    ok(false, "Request should not have succeeded!");
+  } catch (err) {
+    // XXX: Switched to from ok() to todo_is() in Bug 1467712. Follow up in
+    // 1500960
+    // This is throwing because of
+    // `gInspectee.querySelector("#z").parentNode = null;` two blocks above...
+    // Even if you fix that, the test is still failing because "#a" was removed
+    // by the previous test. I am switching this to "#z" because I think that
+    // was the original intent. Still not failing with the expected error message
+    // Needs more work.
+    // ok(err, "noSuchActor", "Should have lost the race.");
+    is(
+      walker._retainedOrphans.size,
+      0,
+      "Should have no more retained orphans."
+    );
+    // Don't re-throw the error.
+  }
+});