feat!: enable mocking Temporal without fake timers

docs/api/vi.md

@@ -1159,7 +1159,7 @@ await vi.runOnlyPendingTimersAsync()
 function setSystemTime(date: string | number | Date): Vitest
 ```
 
-If fake timers are enabled, this method simulates a user changing the system clock (will affect date related API like `hrtime`, `performance.now` or `new Date()`) - however, it will not fire any timers. If fake timers are not enabled, this method will only mock `Date.*` calls.
+If fake timers are enabled, this method simulates a user changing the system clock (will affect date related API like `hrtime`, `performance.now` or `new Date()`) - however, it will not fire any timers. If fake timers are not enabled, this method will only mock `Date.*` and `Temporal.Now.*` calls.
 
 Useful if you need to test anything that depends on the current date - for example [Luxon](https://github.com/moment/luxon/) calls inside your code.
 

docs/guide/migration.md

@@ -147,6 +147,15 @@ Temporal.Now.instant().epochMilliseconds // 0 (was the real time in v4)
 vi.useFakeTimers({ toNotFake: ['Temporal'] })
 ```
 
+### `setSystemTime` Now Mocks Temporal
+
+Previously `vi.setSystemTime` mocked only `Date` without fake timers, but now it also mocks methods of `Temporal.Now`.
+
+```ts
+vi.setSystemTime(0)
+Temporal.Now.instant().epochMilliseconds // 0 (was the real time in v4)
+```
+
 ### `toThrow("")` Matches Any Error Message
 
 [`toThrow`](/api/expect#tothrow) (and its alias `toThrowError`) treats a string argument as a substring of the error message. In Vitest 4 an empty string was special-cased to the `/^$/` pattern, so it matched only an error whose message was empty. It now behaves like any other substring, and an empty string is contained in every message:

docs/guide/mocking.md

@@ -171,7 +171,7 @@ Don't forget that this only [mocks _external_ access](/guide/mocking/modules#moc
 
 ### Mock the current date
 
-To mock `Date`'s time, you can use `vi.setSystemTime` helper function. This value will **not** automatically reset between different tests.
+To mock `Date` and `Temporal`'s time, you can use `vi.setSystemTime` helper function. This value will **not** automatically reset between different tests.
 
 Beware that using `vi.useFakeTimers` also changes the `Date`'s time.
 
@@ -180,6 +180,8 @@ const mockDate = new Date(2022, 0, 1)
 vi.setSystemTime(mockDate)
 const now = new Date()
 expect(now.valueOf()).toBe(mockDate.valueOf())
+const nowInstant = Temporal.Now.instant()
+expect(nowInstant.epochMilliseconds).toBe(mockDate.valueOf())
 // reset mocked time
 vi.useRealTimers()
 ```

packages/vitest/src/integrations/mock/timers.ts

@@ -13,7 +13,8 @@ import type {
 } from '@sinonjs/fake-timers'
 import { withGlobal } from '@sinonjs/fake-timers'
 import { isChildProcess } from '../../runtime/utils'
-import { mockDate, RealDate, resetDate } from './date'
+
+const RealDate = globalThis.Date
 
 export class FakeTimers {
   private _global: typeof globalThis
@@ -134,7 +135,7 @@ export class FakeTimers {
 
   useRealTimers(): void {
     if (this._fakingDate) {
-      resetDate()
+      this._clock.uninstall()
       this._fakingDate = null
     }
 
@@ -147,7 +148,7 @@ export class FakeTimers {
   useFakeTimers(): void {
     const fakeDate = this._fakingDate || Date.now()
     if (this._fakingDate) {
-      resetDate()
+      this._clock.uninstall()
       this._fakingDate = null
     }
 
@@ -197,8 +198,19 @@ export class FakeTimers {
       this._clock.setSystemTime(date)
     }
     else {
-      this._fakingDate = date ?? new Date(this.getRealSystemTime())
-      mockDate(this._fakingDate)
+      const newFakingDate = date ?? new Date(this.getRealSystemTime())
+      if (this._fakingDate) {
+        this._fakingDate = newFakingDate
+        this._clock.setSystemTime(newFakingDate)
+      }
+      else {
+        this._fakingDate = newFakingDate
+        this._clock = this._fakeTimers.install({
+          now: newFakingDate,
+          toFake: ['Date', 'Temporal'],
+          ignoreMissingTimers: true,
+        })
+      }
     }
   }
 

packages/vitest/src/runtime/console.ts

@@ -4,9 +4,10 @@ import { relative } from 'node:path'
 import { Writable } from 'node:stream'
 import { getSafeTimers } from '@vitest/utils/timers'
 import c from 'tinyrainbow'
-import { RealDate } from '../integrations/mock/date'
 import { getWorkerState } from './utils'
 
+const RealDate = globalThis.Date
+
 export const UNKNOWN_TEST_ID = '__vitest__unknown_test__'
 
 function getTaskIdByStack(root: string) {

test/unit/test/timers-temporal.test.ts

@@ -24,3 +24,23 @@ it('Temporal.Now follows fake timers', () => {
   expect(globalThis.Temporal).toBe(real)
   expect(globalThis.Temporal.Now.instant().epochMilliseconds).not.toBe(1234)
 })
+
+it('Temporal.Now follows setSystemTime without fake timers', () => {
+  const real = globalThis.Temporal
+
+  expect(vi.isFakeTimers()).toBe(false)
+  vi.setSystemTime(0)
+  expect(vi.isFakeTimers()).toBe(false)
+  expect(globalThis.Temporal).not.toBe(real)
+  expect(globalThis.Temporal.Now.instant().epochMilliseconds).toBe(0)
+
+  vi.setSystemTime(1234)
+  expect(vi.isFakeTimers()).toBe(false)
+  expect(globalThis.Temporal.Now.instant().epochMilliseconds).toBe(1234)
+
+  // restore
+  vi.useRealTimers()
+  expect(vi.isFakeTimers()).toBe(false)
+  expect(globalThis.Temporal).toBe(real)
+  expect(globalThis.Temporal.Now.instant().epochMilliseconds).not.toBe(1234)
+})