mistykey/packages/backend/test/misc/GodOfTimeService.ts
2025-11-05 19:20:05 -05:00

88 lines
2.3 KiB
TypeScript

/*
* SPDX-FileCopyrightText: hazelnoot and other Sharkey contributors
* SPDX-License-Identifier: AGPL-3.0-only
*/
import { Injectable } from '@nestjs/common';
import { TimeService, Timer } from '@/core/TimeService.js';
/**
* Fake implementation of TimeService that allows manual control of time.
* When this service is used, the flow of time is fully stopped.
*
* Test cases can manually adjust the "now" parameter to move time forwards and backwards.
* When moving forward, timers (interval and timeout) will automatically fire as appropriate.
*/
@Injectable()
export class GodOfTimeService extends TimeService<GodsOwnTimer> {
private _now = 0;
constructor() {
super();
}
/**
* Get or set the current time, in milliseconds since the unix epoch.
*/
public get now() {
return this._now;
}
public set now(value: number) {
// Moving backwards is allowed, for now.
if (value > this._now) {
// Fire all expiring timers in chronological order.
const expiringTimers = this.timers
.values()
.filter(t => t.expiresAt >= value)
.toArray()
.sort((a, b) => a.expiresAt - b.expiresAt);
// Since we sorted the list, this will progressively increase "now" as we handle later and later events.
for (const timer of expiringTimers) {
// When the timer fires, "now" should equal the time that was originally waited for.
this._now = timer.expiresAt;
// Cleanup first in case timer throws an exception.
this.timers.delete(timer.timerId);
timer.callback();
}
}
// Bump up to the final target value
this._now = value;
}
/**
* Clears all timers and resets to time=0.
*/
public reset() {
this.resetTo(0);
}
/**
* Clears all timers and resets to the real-world time.
*/
public resetToNow() {
this.resetTo(Date.now());
}
/**
* Clears all timers and resets to a given time.
*/
public resetTo(to: number) {
this.timers.clear();
this.now = to;
}
protected startNativeTimer(timerId: symbol, repeating: boolean, callback: () => void, delay: number): GodsOwnTimer {
const expiresAt = this.now + delay;
return { timerId, repeating, delay, expiresAt, callback };
}
protected stopNativeTimer(): void {
// no-op - fake timers have no side effects to clean up
}
}
export interface GodsOwnTimer extends Timer {
expiresAt: number;
}