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| -rw-r--r-- | docs/test/time.md | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/docs/test/time.md b/docs/test/time.md index 1cc841fb9..678312903 100644 --- a/docs/test/time.md +++ b/docs/test/time.md @@ -24,6 +24,20 @@ test("it is 2020", () => { }); ``` +To support existing tests that use Jest's `useFakeTimers` and `useRealTimers`, you can use `useFakeTimers` and `useRealTimers`: + +```ts +test("just like in jest", () => { + jest.useFakeTimers(); + jest.setSystemTime(new Date("2020-01-01T00:00:00.000Z")); + expect(new Date().getFullYear()).toBe(2020); + jest.useRealTimers(); + expect(new Date().getFullYear()).toBeGreaterThan(2020); +}); +``` + +Note that we have not implemented builtin support for mocking timers yet, but this is on the roadmap. + ### Reset the system time To reset the system time, pass no arguments to `setSystemTime`: @@ -32,9 +46,13 @@ To reset the system time, pass no arguments to `setSystemTime`: import { setSystemTime, beforeAll } from "bun:test"; test("it was 2020, for a moment.", () => { + // Set it to something! setSystemTime(new Date("2020-01-01T00:00:00.000Z")); expect(new Date().getFullYear()).toBe(2020); + + // reset it! setSystemTime(); + expect(new Date().getFullYear()).toBeGreaterThan(2020); }); ``` |