test: add unit tests

Author: Alfred-Skyblue

packages/runtime-core/__tests__/components/KeepAlive.spec.ts

@@ -23,7 +23,8 @@ import {
   onMounted,
   reactive,
   shallowRef,
-  onDeactivated
+  onDeactivated,
+  watch
 } from '@vue/runtime-test'
 import { KeepAliveProps } from '../../src/components/KeepAlive'
 
@@ -977,4 +978,72 @@ describe('KeepAlive', () => {
     expect(mountedB).toHaveBeenCalledTimes(1)
     expect(unmountedB).toHaveBeenCalledTimes(0)
   })
+
+  test('should pause/resume effectScope in onActivated/onDeactivated', async () => {
+    const renderA = vi.fn(() => 'A')
+    const renderB = vi.fn(() => 'B')
+    const msg = ref('hello')
+    const watchSpy = vi.fn()
+    const A = {
+      name: 'A',
+      setup() {
+        watch(
+          msg,
+          () => {
+            watchSpy()
+          },
+          { immediate: true }
+        )
+        return () => h('div', [renderA(), msg.value])
+      }
+    }
+    const B = {
+      name: 'B',
+      setup() {
+        return renderB
+      }
+    }
+
+    const current = shallowRef(A)
+    const app = createApp({
+      setup() {
+        return () => {
+          return [h(KeepAlive, {}, h(current.value))]
+        }
+      }
+    })
+
+    app.mount(root)
+
+    expect(renderA).toHaveBeenCalledTimes(1)
+    expect(watchSpy).toHaveBeenCalledTimes(1)
+
+    msg.value = 'world'
+    await nextTick()
+    expect(renderA).toHaveBeenCalledTimes(2)
+    expect(watchSpy).toHaveBeenCalledTimes(2)
+
+    // @ts-expect-error
+    current.value = B
+    await nextTick()
+    msg.value = 'foo'
+    await nextTick()
+
+    // The effect should not be executed after deactivated.
+    expect(renderA).toHaveBeenCalledTimes(2)
+    expect(watchSpy).toHaveBeenCalledTimes(2)
+    current.value = A
+    await nextTick()
+
+    // Resume effect execution after activated.
+    // The effect in the render function will be executed immediately after recovery.
+    expect(renderA).toHaveBeenCalledTimes(3)
+    expect(watchSpy).toHaveBeenCalledTimes(2)
+
+    msg.value = 'bar'
+    await nextTick()
+
+    expect(renderA).toHaveBeenCalledTimes(4)
+    expect(watchSpy).toHaveBeenCalledTimes(3)
+  })
 })