1 files changed, 54 insertions, 0 deletions
diff --git a/devtools/server/tests/browser/browser_inspector-release.js b/devtools/server/tests/browser/browser_inspector-release.js
new file mode 100644
index 0000000000..5546da605a
--- /dev/null
+++ b/devtools/server/tests/browser/browser_inspector-release.js
@@ -0,0 +1,54 @@
+/* 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
+);
+
+add_task(async function loadNewChild() {
+  const { target, walker } = await initInspectorFront(
+    MAIN_DOMAIN + "inspector-traversal-data.html"
+  );
+
+  let originalOwnershipSize = 0;
+  let longlist = null;
+  let firstChild = null;
+  const list = await walker.querySelectorAll(walker.rootNode, "#longlist div");
+  // Make sure we have the 26 children of longlist in our ownership tree.
+  is(list.length, 26, "Expect 26 div children.");
+  // Make sure we've read in all those children and incorporated them
+  // in our ownership tree.
+  const items = await list.items();
+  originalOwnershipSize = await assertOwnershipTrees(walker);
+
+  // Here is how the ownership tree is summed up:
+  // #document                      1
+  //   <html>                       1
+  //     <body>                     1
+  //       <div id=longlist>        1
+  //         <div id=a>a</div>   26*2 (each child plus it's singleTextChild)
+  //         ...
+  //         <div id=z>z</div>
+  //                             -----
+  //                               56
+  is(originalOwnershipSize, 56, "Correct number of items in ownership tree");
+  firstChild = items[0].actorID;
+  // Now get the longlist and release it from the ownership tree.
+  const node = await walker.querySelector(walker.rootNode, "#longlist");
+  longlist = node.actorID;
+  await walker.releaseNode(node);
+  // Our ownership size should now be 53 fewer
+  // (we forgot about #longlist + 26 children + 26 singleTextChild nodes)
+  const newOwnershipSize = await assertOwnershipTrees(walker);
+  is(
+    newOwnershipSize,
+    originalOwnershipSize - 53,
+    "Ownership tree should be lower"
+  );
+  // Now verify that some nodes have gone away
+  await checkMissing(target, longlist);
+  await checkMissing(target, firstChild);
+});