fix: close fetch response body on GC (#11467)

This commit fixes fetch response bodies to be automatically closed if
the `Response.body` readable stream goes out of scope and is GC'ed.

1 files changed, 16 insertions, 0 deletions

diff --git a/cli/tests/fetch_response_finalization.js b/cli/tests/fetch_response_finalization.js
new file mode 100644
index 000000000..dd7c355eb
--- /dev/null
+++ b/cli/tests/fetch_response_finalization.js
@@ -0,0 +1,16 @@
+async function doAFetch() {
+  const resp = await fetch("http://localhost:4545/README.md");
+  console.log(Deno.resources()); // print the current resources
+  const _resp = resp;
+  // at this point resp can be GC'ed
+}
+
+await doAFetch(); // create a resource
+
+globalThis.gc(); // force GC
+
+// It is very important that there is a yield here, otherwise the finalizer for
+// the response body is not called and the resource is not closed.
+await new Promise((resolve) => setTimeout(resolve, 0));
+
+console.log(Deno.resources()); // print the current resources