feat(vitest): support vi.waitFor method

docs/api/vi.md

@@ -712,6 +712,12 @@ unmockedIncrement(30) === 31
 
   The implementation is based internally on [`@sinonjs/fake-timers`](https://github.com/sinonjs/fake-timers).
 
+## vi.isFakeTimers
+
+- **Type:** `() => boolean`
+
+  Returns `true` if fake timers are enabled.
+
 ## vi.useRealTimers
 
 - **Type:** `() => Vitest`

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

@@ -175,6 +175,10 @@ export class FakeTimers {
     this._userConfig = config
   }
 
+  isFakeTimers() {
+    return this._fakingTime
+  }
+
   private _checkFakeTimers() {
     if (!this._fakingTime) {
       throw new Error(

packages/vitest/src/integrations/vi.ts

@@ -12,6 +12,7 @@ import { fn, isMockFunction, spies, spyOn } from './spy'
 import { waitFor } from './wait'
 
 interface VitestUtils {
+  isFakeTimers: () => boolean
   useFakeTimers(config?: FakeTimerInstallOpts): this
   useRealTimers(): this
   runOnlyPendingTimers(): this
@@ -215,6 +216,10 @@ function createVitest(): VitestUtils {
       return utils
     },
 
+    isFakeTimers() {
+      return _timers.isFakeTimers()
+    },
+
     useRealTimers() {
       _timers.useRealTimers()
       _mockedDate = null

packages/vitest/src/integrations/wait.ts

@@ -53,12 +53,8 @@ export function waitFor<T>(callback: WaitForCallback<T>, options: number | WaitF
     }
 
     const checkCallback = () => {
-      try {
-        // use fake timers
-        vi.getTimerCount()
+      if (vi.isFakeTimers())
         vi.advanceTimersByTime(interval)
-      }
-      catch {}
 
       if (promiseStatus === 'pending')
         return