fix: delete mock in moduleCache when unmock

packages/vitest/src/runtime/mocker.ts

@@ -280,6 +280,10 @@ export class VitestMocker {
     const mock = this.mockMap.get(suitefile)
     if (mock?.[id])
       delete mock[id]
+
+    const mockId = this.getMockPath(id)
+    if (this.moduleCache.get(mockId))
+      this.moduleCache.delete(mockId)
   }
 
   public mockPath(path: string, external: string | null, factory?: () => any) {

test/core/test/unmock-import.test.ts

@@ -0,0 +1,26 @@
+import { afterEach, beforeEach, expect, test, vi } from 'vitest'
+
+// https://github.com/vitest-dev/vitest/issues/1940
+beforeEach(() => {
+  vi.doMock('/data', () => ({
+    data: {
+      state: 'STARTED',
+    },
+  }))
+})
+afterEach(() => {
+  vi.doUnmock('/data')
+})
+
+test('first import', async () => {
+  // @ts-expect-error I know this
+  const { data } = await import('/data')
+  data.state = 'STOPPED'
+  expect(data.state).toBe('STOPPED')
+})
+
+test('second import should had been re-mock', async () => {
+  // @ts-expect-error I know this
+  const { data } = await import('/data')
+  expect(data.state).toBe('STARTED')
+})