test(shallowRef): add test case

Author: Alfred-Skyblue

packages/dts-test/ref.test-d.ts

@@ -208,6 +208,16 @@ describe('shallowRef with generic', <T extends { name: string }>() => {
   expectType<ShallowRef<T>>(shallowRef(r))
 })
 
+{
+  // should return ShallowRef<T> | Ref<T>, not ShallowRef<T | Ref<T>>
+  expectType<ShallowRef<{ name: string }> | Ref<{ name: string }>>(
+    shallowRef({} as MaybeRef<{ name: string }>)
+  )
+  expectType<ShallowRef<number> | Ref<string[]> | ShallowRef<string>>(
+    shallowRef('' as Ref<string[]> | string | number)
+  )
+}
+
 // proxyRefs: should return `reactive` directly
 const r1 = reactive({
   k: 'v'