日期和时间 – 测试运行器 | Bun 文档

bun:test 允许您在测试中更改时间。

这适用于以下任何一项

Date.now
new Date()
new Intl.DateTimeFormat().format()

定时器目前尚未受到影响，但在 Bun 的未来版本中可能会受到影响。

`setSystemTime`

要更改系统时间，请使用 setSystemTime

import { setSystemTime, beforeAll, test, expect } from "bun:test";

beforeAll(() => {
  setSystemTime(new Date("2020-01-01T00:00:00.000Z"));
});

test("it is 2020", () => {
  expect(new Date().getFullYear()).toBe(2020);
});

为了支持使用 Jest 的 useFakeTimers 和 useRealTimers 的现有测试，您可以使用 useFakeTimers 和 useRealTimers。

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);
});

test("unlike in jest", () => {
  const OriginalDate = Date;
  jest.useFakeTimers();
  if (typeof Bun === "undefined") {
    // In Jest, the Date constructor changes
    // That can cause all sorts of bugs because suddenly Date !== Date before the test.
    expect(Date).not.toBe(OriginalDate);
    expect(Date.now).not.toBe(OriginalDate.now);
  } else {
    // In bun:test, Date constructor does not change when you useFakeTimers
    expect(Date).toBe(OriginalDate);
    expect(Date.now).toBe(OriginalDate.now);
  }
});

定时器——请注意，我们尚未实现对模拟定时器的内置支持，但这已在路线图上。

重置系统时间

要重置系统时间，请不带参数传递给 setSystemTime

import { setSystemTime, expect, test } 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);
});

设置时区

要更改时区，可以将 $TZ 环境变量传递给 bun test。

TZ=America/Los_Angeles bun test

或者在运行时设置 process.env.TZ

import { test, expect } from "bun:test";

test("Welcome to California!", () => {
  process.env.TZ = "America/Los_Angeles";
  expect(new Date().getTimezoneOffset()).toBe(420);
  expect(new Intl.DateTimeFormat().resolvedOptions().timeZone).toBe(
    "America/Los_Angeles",
  );
});

test("Welcome to New York!", () => {
  // Unlike in Jest, you can set the timezone multiple times at runtime and it will work.
  process.env.TZ = "America/New_York";
  expect(new Date().getTimezoneOffset()).toBe(240);
  expect(new Intl.DateTimeFormat().resolvedOptions().timeZone).toBe(
    "America/New_York",
  );
});