test: test unwrapping computed refs

packages/reactivity/src/reactive.ts

@@ -1,13 +1,11 @@
 import { isObject, toTypeString } from '@vue/shared'
 import { mutableHandlers, readonlyHandlers } from './baseHandlers'
-
 import {
   mutableCollectionHandlers,
   readonlyCollectionHandlers
 } from './collectionHandlers'
-
-import { UnwrapNestedRefs } from './ref'
 import { ReactiveEffect } from './effect'
+import { UnwrapRef, Ref } from './ref'
 
 // The main WeakMap that stores {target -> key -> dep} connections.
 // Conceptually, it's easier to think of a dependency as a Dep class
@@ -40,6 +38,9 @@ const canObserve = (value: any): boolean => {
   )
 }
 
+// only unwrap nested ref
+type UnwrapNestedRefs<T> = T extends Ref ? T : UnwrapRef<T>
+
 export function reactive<T extends object>(target: T): UnwrapNestedRefs<T>
 export function reactive(target: object) {
   // if trying to observe a readonly proxy, return the readonly version.