1 files changed, 70 insertions, 0 deletions
diff --git a/docshell/test/unit/test_browsing_context_structured_clone.js b/docshell/test/unit/test_browsing_context_structured_clone.js
new file mode 100644
index 0000000000..1c91a9b0b2
--- /dev/null
+++ b/docshell/test/unit/test_browsing_context_structured_clone.js
@@ -0,0 +1,70 @@
+"use strict";
+
+add_task(async function test_BrowsingContext_structured_clone() {
+  let browser = Services.appShell.createWindowlessBrowser(false);
+
+  let frame = browser.document.createElement("iframe");
+
+  await new Promise(r => {
+    frame.onload = () => r();
+    browser.document.body.appendChild(frame);
+  });
+
+  let { browsingContext } = frame;
+
+  let sch = new StructuredCloneHolder("debug name", "<anonymized> debug name", {
+    browsingContext,
+  });
+
+  let deserialize = () => sch.deserialize({}, true);
+
+  // Check that decoding a live browsing context produces the correct
+  // object.
+  equal(
+    deserialize().browsingContext,
+    browsingContext,
+    "Got correct browsing context from StructuredClone deserialize"
+  );
+
+  // Check that decoding a second time still succeeds.
+  equal(
+    deserialize().browsingContext,
+    browsingContext,
+    "Got correct browsing context from second StructuredClone deserialize"
+  );
+
+  // Destroy the browsing context and make sure that the decode fails
+  // with a DataCloneError.
+  //
+  // Making sure the BrowsingContext is actually destroyed by the time
+  // we do the second decode is a bit tricky. We obviously have clear
+  // our local references to it, and give the GC a chance to reap them.
+  // And we also, of course, have to destroy the frame that it belongs
+  // to, or its frame loader and window global would hold it alive.
+  //
+  // Beyond that, we don't *have* to reload or destroy the parent
+  // document, but we do anyway just to be safe.
+  //
+
+  frame.remove();
+  frame = null;
+  browsingContext = null;
+
+  browser.document.location.reload();
+  browser.close();
+
+  // We will schedule a precise GC and do both GC and CC a few times, to make
+  // sure we have completely destroyed the WindowGlobal actors (which keep
+  // references to their BrowsingContexts) in order
+  // to allow their (now snow-white) references to be collected.
+  await schedulePreciseGCAndForceCC(3);
+
+  // OK. We can be fairly confident that the BrowsingContext object
+  // stored in our structured clone data has been destroyed. Make sure
+  // that attempting to decode it again leads to the appropriate error.
+  Assert.throws(
+    deserialize,
+    e => e.name === "DataCloneError",
+    "Should get a DataCloneError when trying to decode a dead BrowsingContext"
+  );
+});