1 files changed, 102 insertions, 0 deletions
diff --git a/devtools/server/tests/browser/browser_inspector-remove.js b/devtools/server/tests/browser/browser_inspector-remove.js
new file mode 100644
index 0000000000..8338e40ea2
--- /dev/null
+++ b/devtools/server/tests/browser/browser_inspector-remove.js
@@ -0,0 +1,102 @@
+/* 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 testRemoveSubtree() {
+  const { target, walker } = await initInspectorFront(
+    MAIN_DOMAIN + "inspector-traversal-data.html"
+  );
+
+  await SpecialPowers.spawn(gBrowser.selectedBrowser, [], function () {
+    function ignoreNode(node) {
+      // Duplicate the walker logic to skip blank nodes...
+      return (
+        node.nodeType === content.Node.TEXT_NODE &&
+        !/[^\s]/.test(node.nodeValue)
+      );
+    }
+
+    let nextSibling = content.document.querySelector("#longlist").nextSibling;
+    while (nextSibling && ignoreNode(nextSibling)) {
+      nextSibling = nextSibling.nextSibling;
+    }
+
+    let previousSibling =
+      content.document.querySelector("#longlist").previousSibling;
+    while (previousSibling && ignoreNode(previousSibling)) {
+      previousSibling = previousSibling.previousSibling;
+    }
+    content.nextSibling = nextSibling;
+    content.previousSibling = previousSibling;
+  });
+
+  let originalOwnershipSize = 0;
+  const longlist = await walker.querySelector(walker.rootNode, "#longlist");
+  const longlistID = longlist.actorID;
+  await walker.children(longlist);
+  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");
+
+  const onMutation = waitForMutation(walker, isChildList);
+  const siblings = await walker.removeNode(longlist);
+
+  await SpecialPowers.spawn(
+    gBrowser.selectedBrowser,
+    [[siblings.previousSibling.actorID, siblings.nextSibling.actorID]],
+    function ([previousActorID, nextActorID]) {
+      const { require } = ChromeUtils.importESModule(
+        "resource://devtools/shared/loader/Loader.sys.mjs"
+      );
+      const {
+        DevToolsServer,
+      } = require("resource://devtools/server/devtools-server.js");
+
+      // Convert actorID to current compartment string otherwise
+      // searchAllConnectionsForActor is confused and won't find the actor.
+      previousActorID = String(previousActorID);
+      nextActorID = String(nextActorID);
+      const previous =
+        DevToolsServer.searchAllConnectionsForActor(previousActorID);
+      const next = DevToolsServer.searchAllConnectionsForActor(nextActorID);
+
+      is(
+        previous.rawNode,
+        content.previousSibling,
+        "Should have returned the previous sibling."
+      );
+      is(
+        next.rawNode,
+        content.nextSibling,
+        "Should have returned the next sibling."
+      );
+    }
+  );
+  await onMutation;
+  // Our ownership size should now be 51 fewer (we forgot about #longlist + 26
+  // children + 26 singleTextChild nodes, but learned about #longlist's
+  // prev/next sibling)
+  const newOwnershipSize = await assertOwnershipTrees(walker);
+  is(
+    newOwnershipSize,
+    originalOwnershipSize - 51,
+    "Ownership tree should be lower"
+  );
+  // Now verify that some nodes have gone away
+  return checkMissing(target, longlistID);
+});