fix(types): fix shallowRef's return type (#12979)

close #12978

src/v3/reactivity/ref.ts

@@ -40,9 +40,7 @@ export function isRef(r: any): r is Ref {
  return !!(r && (r as Ref).__v_isRef === true)
 }
 
-export function ref<T extends object>(
- value: T
-): [T] extends [Ref] ? T : Ref<UnwrapRef<T>>
+export function ref<T extends Ref>(value: T): T
 export function ref<T>(value: T): Ref<UnwrapRef<T>>
 export function ref<T = any>(): Ref<T | undefined>
 export function ref(value?: unknown) {
@@ -53,9 +51,8 @@ declare const ShallowRefMarker: unique symbol
 
 export type ShallowRef<T = any> = Ref<T> & { [ShallowRefMarker]?: true }
 
-export function shallowRef<T extends object>(
- value: T
-): T extends Ref ? T : ShallowRef<T>
+export function shallowRef<T>(value: T | Ref<T>): Ref<T> | ShallowRef<T>
+export function shallowRef<T extends Ref>(value: T): T
 export function shallowRef<T>(value: T): ShallowRef<T>
 export function shallowRef<T = any>(): ShallowRef<T | undefined>
 export function shallowRef(value?: unknown) {

types/test/v3/reactivity-test.ts

@@ -15,7 +15,7 @@ import {
  set,
  del
 } from '../../index'
-import { describe, expectType } from '../utils'
+import { IsUnion, describe, expectType } from '../utils'
 
 function plainType(arg: number | Ref<number>) {
  // ref coercing
@@ -385,3 +385,14 @@ describe('set/del', () => {
  // @ts-expect-error
  del([], 'fse', 123)
 })
+
+
+{
+ //#12978
+ type Steps = { step: '1' } | { step: '2' }
+ const shallowUnionGenParam = shallowRef<Steps>({ step: '1' })
+ const shallowUnionAsCast = shallowRef({ step: '1' } as Steps)
+
+ expectType<IsUnion<typeof shallowUnionGenParam>>(false)
+ expectType<IsUnion<typeof shallowUnionAsCast>>(false)
+}

types/test/v3/watch-test.ts

@@ -1,4 +1,4 @@
-import { ref, computed, watch } from '../../index'
+import { ref, computed, watch, shallowRef } from '../../index'
 import { expectType } from '../utils'
 
 const source = ref('foo')
@@ -76,3 +76,17 @@ watch([someRef, otherRef], values => {
  // no type error
  console.log(value2.a)
 })
+
+{
+ //#12978
+ type Steps = { step: '1' } | { step: '2' }
+ const shallowUnionGenParam = shallowRef<Steps>({ step: '1' })
+ const shallowUnionAsCast = shallowRef({ step: '1' } as Steps)
+
+ watch(shallowUnionGenParam, value => {
+ expectType<Steps>(value)
+ })
+ watch(shallowUnionAsCast, value => {
+ expectType<Steps>(value)
+ })
+}