feat(reactivePick): add test cases (#2653)

* feat(reactivePick): add test cases

* fix(reactivePick):  eslint

Co-authored-by: 丶远方 <pantengyang@cybstar.com>
Co-authored-by: wheat <jacobrclevenger@gmail.com>

packages/shared/reactivePick/index.test.ts

@@ -0,0 +1,47 @@
+import { reactive } from 'vue-demi'
+import { reactivePick } from '../reactivePick'
+
+describe('reactivePick', () => {
+  it('should be defined', () => {
+    expect(reactivePick).toBeDefined()
+  })
+
+  it('should work', () => {
+    const source = reactive({
+      foo: 'foo',
+      bar: 'bar',
+    })
+    const state = reactivePick(source, 'bar')
+
+    expect(state).toEqual({
+      bar: 'bar',
+    })
+
+    source.foo = 'foo2'
+
+    expect(state).toEqual({
+      bar: 'bar',
+    })
+
+    source.bar = 'bar1'
+
+    expect(state).toEqual({
+      bar: 'bar1',
+    })
+  })
+
+  it('should write back', () => {
+    const source = reactive({
+      foo: 'foo',
+      bar: 'bar',
+    })
+    const state = reactivePick(source, 'bar')
+
+    state.bar = 'bar2'
+
+    expect(source).toEqual({
+      foo: 'foo',
+      bar: 'bar2',
+    })
+  })
+})