can1357
1d8ee5a891
- Replaced Bun.sleep with scheduler.wait for Node-compatible cancellable sleeps. - Added module-level timestamp gate to skip yields within 50ms of the last one. - Threaded AbortSignal through ExponentialYield.sleep to cancel losing timers in race. - Added tests covering gate behaviour and stray-timer cancellation.
60 lines
2.4 KiB
TypeScript
60 lines
2.4 KiB
TypeScript
import { describe, expect, it } from "bun:test";
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import { ExponentialYield, yieldIfDue } from "../src/utils/yield";
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const YIELD_SLEEP_MS = 20;
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const YIELD_INTERVAL_MS = 50;
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describe("yieldIfDue", () => {
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it("sleeps on the first call and primes the timestamp gate", async () => {
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// Prime the gate so the next call is in a known state.
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await yieldIfDue();
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const start = performance.now();
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await yieldIfDue();
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const elapsed = performance.now() - start;
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// Within the 50 ms gate window — must be a near-instant return.
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expect(elapsed).toBeLessThan(YIELD_SLEEP_MS / 2);
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});
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it("sleeps again once the gate window elapses", async () => {
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await yieldIfDue();
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// Wait past the gate the same way callers would (real time).
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await new Promise<void>(r => setTimeout(r, YIELD_INTERVAL_MS + 5));
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const start = performance.now();
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await yieldIfDue();
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const elapsed = performance.now() - start;
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expect(elapsed).toBeGreaterThanOrEqual(YIELD_SLEEP_MS - 5);
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});
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});
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describe("ExponentialYield.race", () => {
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it("returns the racer's value as soon as it settles", async () => {
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const ey = new ExponentialYield({ minMs: 5_000, maxMs: 10_000 });
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const racer = new Promise<string>(r => setTimeout(() => r("done"), 10));
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const start = performance.now();
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const out = await ey.race([racer]);
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const elapsed = performance.now() - start;
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expect(out).toBe("done");
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// The 5s yield must not have delayed us: settle within a comfy margin.
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expect(elapsed).toBeLessThan(500);
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});
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it("cancels the losing sleep so it does not keep the loop alive", async () => {
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// If the losing Bun.sleep weren't cancelled, this test would block for
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// the full minMs after the racer wins, since the prior implementation
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// kept fresh timers ticking. We pick a minMs far larger than the racer
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// delay and assert we return well before it.
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const ey = new ExponentialYield({ minMs: 2_000, maxMs: 2_000 });
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const racer = new Promise<number>(r => setTimeout(() => r(42), 20));
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const start = performance.now();
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const out = await ey.race([racer]);
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const elapsed = performance.now() - start;
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expect(out).toBe(42);
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expect(elapsed).toBeLessThan(500);
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// After race resolves, ensure the AbortController-driven cancel really
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// unblocked the underlying timer: a short follow-up sleep should not
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// be perturbed by residual pending timers. (Sanity: this returns.)
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await new Promise<void>(r => setTimeout(r, 30));
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});
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});
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