fix: nextTick mocking error message to mention correct config option (#4215)

Author: AriPerkkio

docs/api/vi.md

@@ -698,7 +698,7 @@ unmockedIncrement(30) === 31
 
   To enable mocking timers, you need to call this method. It will wrap all further calls to timers (such as `setTimeout`, `setInterval`, `clearTimeout`, `clearInterval`, `nextTick`, `setImmediate`, `clearImmediate`, and `Date`), until [`vi.useRealTimers()`](#vi-userealtimers) is called.
 
-  Mocking `nextTick` is not supported when running Vitest inside `node:child_process` by using `--no-threads`. NodeJS uses `process.nextTick` internally in `node:child_process` and hangs when it is mocked. Mocking `nextTick` is supported when running Vitest with `--threads`.
+  Mocking `nextTick` is not supported when running Vitest inside `node:child_process` by using `--pool=forks`. NodeJS uses `process.nextTick` internally in `node:child_process` and hangs when it is mocked. Mocking `nextTick` is supported when running Vitest with `--pool=threads`.
 
   The implementation is based internally on [`@sinonjs/fake-timers`](https://github.com/sinonjs/fake-timers).
 

packages/vitest/src/integrations/vi.ts

@@ -211,7 +211,7 @@ function createVitest(): VitestUtils {
       if (workerState.isChildProcess) {
         if (config?.toFake?.includes('nextTick') || workerState.config?.fakeTimers?.toFake?.includes('nextTick')) {
           throw new Error(
-            'vi.useFakeTimers({ toFake: ["nextTick"] }) is not supported in node:child_process. Use --threads if mocking nextTick is required.',
+            'vi.useFakeTimers({ toFake: ["nextTick"] }) is not supported in node:child_process. Use --pool=threads if mocking nextTick is required.',
           )
         }
       }

test/config/test/failures.test.ts

@@ -95,7 +95,7 @@ test('nextTick cannot be mocked inside child_process', async () => {
     include: ['./fixtures/test/fake-timers.test.ts'],
   })
 
-  expect(stderr).toMatch('Error: vi.useFakeTimers({ toFake: ["nextTick"] }) is not supported in node:child_process. Use --threads if mocking nextTick is required.')
+  expect(stderr).toMatch('Error: vi.useFakeTimers({ toFake: ["nextTick"] }) is not supported in node:child_process. Use --pool=threads if mocking nextTick is required.')
 })
 
 test('nextTick can be mocked inside worker_threads', async () => {