fix(runtime): event loop panics in classic workers (#11756)

Classic worker scripts are now executed in the context of a Tokio
runtime. This does mean we can not spawn more tokio runtimes in
"op_worker_sync_fetch". We instead spawn a new thread there, that can
create a new Tokio runtime that we can use to block the worker thread.

3 files changed, 12 insertions, 0 deletions

diff --git a/cli/tests/integration/run_tests.rs b/cli/tests/integration/run_tests.rs
index c7e0325ec..981b85199 100644
--- a/cli/tests/integration/run_tests.rs
+++ b/cli/tests/integration/run_tests.rs
@@ -1109,6 +1109,13 @@ itest!(import_file_with_colon {
   output: "import_file_with_colon.ts.out",
   http_server: true,
 });
+
+itest!(classic_workers_event_loop {
+  args:
+    "run --enable-testing-features-do-not-use classic_workers_event_loop.js",
+  output: "classic_workers_event_loop.js.out",
+});
+
 // FIXME(bartlomieju): disabled, because this test is very flaky on CI
 // itest!(local_sources_not_cached_in_memory {
 //   args: "run --allow-read --allow-write no_mem_cache.js",
diff --git a/cli/tests/testdata/classic_workers_event_loop.js b/cli/tests/testdata/classic_workers_event_loop.js
new file mode 100644
index 000000000..810a6df7f
--- /dev/null
+++ b/cli/tests/testdata/classic_workers_event_loop.js
@@ -0,0 +1,4 @@
+new Worker(
+  "data:application/javascript,setTimeout(() => {console.log('done'); self.close()}, 1000)",
+  { type: "classic" },
+);
diff --git a/cli/tests/testdata/classic_workers_event_loop.js.out b/cli/tests/testdata/classic_workers_event_loop.js.out
new file mode 100644
index 000000000..19f86f493
--- /dev/null
+++ b/cli/tests/testdata/classic_workers_event_loop.js.out
@@ -0,0 +1 @@
+done