test(watch): watching a reactive array (vuejs#10848)

packages/runtime-core/__tests__/apiWatch.spec.ts

@@ -96,6 +96,30 @@ describe('api: watch', () => {
     expect(spy).toBeCalledWith([1], [1], expect.anything())
   })
 
+  it('should not call functions inside a reactive source array', () => {
+    const spy1 = vi.fn()
+    const array = reactive([spy1])
+    const spy2 = vi.fn()
+    watch(array, spy2, { immediate: true })
+    expect(spy1).toBeCalledTimes(0)
+    expect(spy2).toBeCalledWith([spy1], undefined, expect.anything())
+  })
+
+  it('should not unwrap refs in a reactive source array', async () => {
+    const val = ref({ foo: 1 })
+    const array = reactive([val])
+    const spy = vi.fn()
+    watch(array, spy, { immediate: true })
+    expect(spy).toBeCalledTimes(1)
+    expect(spy).toBeCalledWith([val], undefined, expect.anything())
+
+    // deep by default
+    val.value.foo++
+    await nextTick()
+    expect(spy).toBeCalledTimes(2)
+    expect(spy).toBeCalledWith([val], [val], expect.anything())
+  })
+
   it('should not fire if watched getter result did not change', async () => {
     const spy = vi.fn()
     const n = ref(0)
@@ -186,6 +210,24 @@ describe('api: watch', () => {
     expect(dummy).toBe(1)
   })
 
+  it('directly watching reactive array with explicit deep: false', async () => {
+    const val = ref(1)
+    const array: any[] = reactive([val])
+    const spy = vi.fn()
+    watch(array, spy, { immediate: true, deep: false })
+    expect(spy).toBeCalledTimes(1)
+    expect(spy).toBeCalledWith([val], undefined, expect.anything())
+
+    val.value++
+    await nextTick()
+    expect(spy).toBeCalledTimes(1)
+
+    array[1] = 2
+    await nextTick()
+    expect(spy).toBeCalledTimes(2)
+    expect(spy).toBeCalledWith([val, 2], [val, 2], expect.anything())
+  })
+
   // #9916
   it('watching shallow reactive array with deep: false', async () => {
     class foo {