fix: preserve cancellation when change-time settles

src/artifacts/ChangeTimeBaseline.test.ts

@@ -271,3 +271,17 @@ it("does not consume Windows limits on other hosts and preserves cancellation du
     ),
   ).rejects.toBe(reason);
 });
+
+it("preserves cancellation during a Windows read even when the timestamp is stable", async () => {
+  const controller = new AbortController();
+  const reason = new Error("cancelled during read");
+  await expect(
+    settleChangeTimeBaseline(
+      async () => {
+        controller.abort(reason);
+        return statsAt(1);
+      },
+      { platform: "win32", now: () => 10000, signal: controller.signal },
+    ),
+  ).rejects.toBe(reason);
+});

src/filesystem/ChangeTimeBaseline.ts

@@ -28,7 +28,8 @@ export interface ChangeTimeSettleSeams {
   readonly sleep?: ((delayMs: number) => Promise<void>) | undefined;
   /** Launch environment. Omission reads `process.env`. */
   readonly environment?:
-    Readonly<Record<string, string | undefined>> | undefined;
+    | Readonly<Record<string, string | undefined>>
+    | undefined;
   /** Already resolved budget. Omission parses `environment`. */
   readonly limits?: WindowsChangeTimeSettleLimits | undefined;
   /** Cancels the wait; the last observation is not returned once aborted. */
@@ -111,10 +112,10 @@ export const settleChangeTimeBaseline = async (
   const sleep = seams.sleep ?? defaultSleep;
   let observed = await read();
   for (let poll = 0; poll < limits.maxPolls; poll += 1) {
+    throwIfAborted(seams);
     if (!changeTimeMayStillDrift(observed, settled)) return observed;
     // A settle window is bounded by driftMs, not by the poll budget, so a
     // cancelled scope must not keep an inventory waiting it out.
-    throwIfAborted(seams);
     await sleep(limits.pollMs);
     throwIfAborted(seams);
     observed = await read();