This package provides utilities for testing.
```js import { assertSpyCalls, spy } from "@std/testing/mock"; import { FakeTime } from "@std/testing/time"; function secondInterval(cb: () => void): number { return setInterval(cb, 1000); } Deno.test("secondInterval calls callback every second and stops after being cleared", () => { using time = new FakeTime(); const cb = spy(); const intervalId = secondInterval(cb); assertSpyCalls(cb, 0); time.tick(500); assertSpyCalls(cb, 0); time.tick(500); assertSpyCalls(cb, 1); time.tick(3500); assertSpyCalls(cb, 4); clearInterval(intervalId); time.tick(1000); assertSpyCalls(cb, 4); }); ``` ### Add to your project ```sh deno add jsr:@std/testing ``` See all symbols in @std/testing on