repro: 'set' on proxy: trap returned falsish for property with Vue v3…

….2.45

This comes from the fact that mocks are set via a mixin (Options API) and we run into the more strict behavior of Vue v3.2.45
introduced in vuejs/core@f73925d#diff-ea4d1ddabb7e22e17e80ada458eef70679af4005df2a1a6b73418fec897603ceR404

tests/components/ScriptSetup.vue

@@ -12,6 +12,6 @@ const inc = () => {
 </script>
 
 <template>
-  <button @click="inc">{{ count }}</button>
+  <button @click="inc()">{{ count }}</button>
   <Hello />
 </template>

tests/expose.spec.ts

@@ -1,4 +1,4 @@
-import { describe, expect, it } from 'vitest'
+import { describe, expect, it, vi } from 'vitest'
 import { nextTick } from 'vue'
 import { mount } from '../src'
 import Hello from './components/Hello.vue'
@@ -61,4 +61,21 @@ describe('expose', () => {
     await nextTick()
     expect(wrapper.html()).toContain('2')
   })
+
+  it('should not throw when mocking', async () => {
+    const spiedIncrement = vi.fn()
+    const wrapper = mount(ScriptSetup, {
+      global: {
+        mocks: {
+          inc: spiedIncrement
+        }
+      }
+    })
+
+    await wrapper.find('button').trigger('click')
+    await nextTick()
+
+    expect(spiedIncrement).toHaveBeenCalled()
+    expect(wrapper.html()).toContain('0')
+  })
 })