2.0.0-beta.15: uncaught error in an async-generator `action()` freezes the JS thread

[brenelz]

Describe the bug

When an action() is given an async generator (async function*) and an uncaught error occurs inside it, the returned promise never settles and the whole JS thread freezes in an infinite microtask loop (frozen tab in the browser, hung process in Node). The same code written as a sync function* rejects correctly.

Since the transition's iterator is never removed from _actions, the transition also never completes.

Reproduction

import { action } from "@solidjs/signals";

const act = action(async function* () {
  throw new Error("boom"); // any uncaught throw: failed fetch, TypeError, etc.
});

act(); // never settles; event loop is starved — a setTimeout after this never fires

Real-world shape:

const save = action(async function* (text: string) {
  const res = await fetch("/api/todos", { method: "POST", body: text });
  if (!res.ok) throw new Error("save failed"); // ← freezes the tab
  return yield res.json();
});