fix(reactivity): avoid length mutating array methods causing infinite updates (#2138)

fix #2137

Co-authored-by: Evan You <yyx990803@gmail.com>

packages/reactivity/__tests__/effect.spec.ts

@@ -358,6 +358,29 @@ describe('reactivity/effect', () => {
     expect(counterSpy).toHaveBeenCalledTimes(2)
   })
 
+  it('should avoid infinite recursive loops when use Array.prototype.push/unshift/pop/shift', () => {
+    ;(['push', 'unshift'] as const).forEach(key => {
+      const arr = reactive<number[]>([])
+      const counterSpy1 = jest.fn(() => (arr[key] as any)(1))
+      const counterSpy2 = jest.fn(() => (arr[key] as any)(2))
+      effect(counterSpy1)
+      effect(counterSpy2)
+      expect(arr.length).toBe(2)
+      expect(counterSpy1).toHaveBeenCalledTimes(1)
+      expect(counterSpy2).toHaveBeenCalledTimes(1)
+    })
+    ;(['pop', 'shift'] as const).forEach(key => {
+      const arr = reactive<number[]>([1, 2, 3, 4])
+      const counterSpy1 = jest.fn(() => (arr[key] as any)())
+      const counterSpy2 = jest.fn(() => (arr[key] as any)())
+      effect(counterSpy1)
+      effect(counterSpy2)
+      expect(arr.length).toBe(2)
+      expect(counterSpy1).toHaveBeenCalledTimes(1)
+      expect(counterSpy2).toHaveBeenCalledTimes(1)
+    })
+  })
+
   it('should allow explicitly recursive raw function loops', () => {
     const counter = reactive({ num: 0 })
     const numSpy = jest.fn(() => {