chore(workers): Test that closing a worker closes any child workers (#12215)

Before #12156, closing a worker which had children would cause a panic
(https://github.com/denoland/deno/issues/11342#issuecomment-918327693).

After that PR, closing a worker will also close any child workers.

1 files changed, 13 insertions, 0 deletions

diff --git a/cli/tests/testdata/workers/close_nested_parent.js b/cli/tests/testdata/workers/close_nested_parent.js
new file mode 100644
index 000000000..c528632ce
--- /dev/null
+++ b/cli/tests/testdata/workers/close_nested_parent.js
@@ -0,0 +1,13 @@
+// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.
+
+console.log("Starting the parent worker");
+
+new Worker(
+  new URL("./close_nested_child.js", import.meta.url),
+  { type: "module" },
+);
+
+self.addEventListener("message", () => {
+  console.log("Closing");
+  self.close();
+});