fix: cleanup last mocked cache when call vi.doMock (#2872)

fix #2870

docs/api/vi.md

@@ -221,13 +221,11 @@ increment(1) === 2
 let mockedIncrement = 100
 
 beforeEach(() => {
-  // simple doMock doesn't clear the previous cache, so we need to clear it manually here
-  vi.doUnmock('./increment.js')
   // you can access variables inside a factory
-  vi.doMock('./increment.js', () => ({ increment: () => mockedIncrement++ }))
+  vi.doMock('./increment.js', () => ({ increment: () => ++mockedIncrement }))
 })
 
-test('importing the next module imports mocked one', () => {
+test('importing the next module imports mocked one', async () => {
   // original import WAS NOT MOCKED, because vi.doMock is evaluated AFTER imports
   expect(increment(1)).toBe(2)
   const { increment: mockedIncrement } = await import('./increment.js')

packages/vitest/src/runtime/mocker.ts

@@ -60,6 +60,12 @@ export class VitestMocker {
     return this.executor.moduleCache
   }
 
+  private deleteCachedItem(id: string) {
+    const mockId = this.getMockPath(id)
+    if (this.moduleCache.has(mockId))
+      this.moduleCache.delete(mockId)
+  }
+
   public getSuiteFilepath(): string {
     return getWorkerState().filepath || 'global'
   }
@@ -292,9 +298,7 @@ export class VitestMocker {
     if (mock && id in mock)
       delete mock[id]
 
-    const mockId = this.getMockPath(id)
-    if (this.moduleCache.get(mockId))
-      this.moduleCache.delete(mockId)
+    this.deleteCachedItem(id)
   }
 
   public mockPath(originalId: string, path: string, external: string | null, factory?: MockFactory) {
@@ -309,6 +313,7 @@ export class VitestMocker {
 
     this.mockMap.set(suitefile, mocks)
     this.resolveCache.set(suitefile, resolves)
+    this.deleteCachedItem(id)
   }
 
   public async importActual<T>(rawId: string, importee: string): Promise<T> {

test/core/test/do-mock.test.ts

@@ -0,0 +1,32 @@
+import { expect, test, vi } from 'vitest'
+
+test('doMock works', async () => {
+  const { increment: incrementWith1 } = await import('./fixtures/increment')
+  expect(incrementWith1(1)).toBe(2)
+
+  vi.doMock('./fixtures/increment', () => ({
+    increment: (num: number) => num + 10,
+  }))
+
+  const { increment: incrementWith10 } = await import('./fixtures/increment')
+
+  expect(incrementWith10(1)).toBe(11)
+})
+
+test('the second doMock can override the first doMock', async () => {
+  vi.doMock('./fixtures/increment', () => ({
+    increment: (num: number) => num + 10,
+  }))
+
+  const { increment: incrementWith1 } = await import('./fixtures/increment')
+
+  expect(incrementWith1(1)).toBe(11)
+
+  vi.doMock('./fixtures/increment', () => ({
+    increment: (num: number) => num + 20,
+  }))
+
+  const { increment: incrementWith20 } = await import('./fixtures/increment')
+
+  expect(incrementWith20(1)).toBe(21)
+})

test/core/test/fixtures/increment.ts

@@ -0,0 +1 @@
+export const increment = (num: number) => num + 1