feat(reactivity): support default value in toRef()

2021-12-11 16:41:58 +08:00
parent d0ea900922
commit 2db9c909c2
3 changed files with 41 additions and 3 deletions
--- a/packages/reactivity/tests/ref.spec.ts
+++ b/packages/reactivity/tests/ref.spec.ts
@@ -269,6 +269,18 @@ describe('reactivity/ref', () => {
    expect(toRef(r, 'x')).toBe(r.x)
  })

+  test('toRef default value', () => {
+    const a: { x: number | undefined } = { x: undefined }
+    const x = toRef(a, 'x', 1)
+    expect(x.value).toBe(1)
+
+    a.x = 2
+    expect(x.value).toBe(2)
+
+    a.x = undefined
+    expect(x.value).toBe(1)
+  })
+
  test('toRefs', () => {
    const a = reactive({
      x: 1,