fix(usage): reject pre-cancelled quota waits

Author: outlier27-cell

extensions/usage/providers/utils.ts

@@ -82,6 +82,7 @@ export async function waitForUsage<T>(
   promise: Promise<T>,
   signal: AbortSignal,
 ): Promise<T> {
+  signal.throwIfAborted();
   let onAbort: (() => void) | undefined;
   const aborted = new Promise<never>((_resolve, reject) => {
     onAbort = () => reject(signal.reason);

tests/extensions/usage/providers.test.ts

@@ -11,6 +11,7 @@ import { DEFAULT_ADAPTERS } from "../../../extensions/usage/providers/registry.t
 import {
   computeUsageStatus,
   parseTimestamp,
+  waitForUsage,
 } from "../../../extensions/usage/providers/utils.ts";
 
 function jwt(payload: Record<string, unknown>) {
@@ -25,6 +26,17 @@ function payloadFetch(payload: unknown): typeof fetch {
   return async () => Response.json(payload);
 }
 
+test("a pre-cancelled quota wait cannot return an already-fulfilled result", async () => {
+  const controller = new AbortController();
+  const reason = new Error("cancelled fixture");
+  controller.abort(reason);
+
+  await assert.rejects(
+    waitForUsage(Promise.resolve("stale quota"), controller.signal),
+    (error: unknown) => error === reason,
+  );
+});
+
 test("Cursor uses its session cookie, authoritative percentages and independent account metadata", async () => {
   const calls: Array<{ url: string; init?: RequestInit }> = [];
   const report = await cursorAdapter.fetchUsage(