fix(types): keep the original type when unwrapping markRaw (#3791)

packages/reactivity/src/reactive.ts

@@ -11,7 +11,7 @@ import {
   shallowCollectionHandlers,
   shallowReadonlyCollectionHandlers
 } from './collectionHandlers'
-import { UnwrapRefSimple, Ref } from './ref'
+import { UnwrapRefSimple, Ref, RawSymbol } from './ref'
 
 export const enum ReactiveFlags {
   SKIP = '__v_skip',
@@ -241,7 +241,9 @@ export function toRaw<T>(observed: T): T {
   return raw ? toRaw(raw) : observed
 }
 
-export function markRaw<T extends object>(value: T): T {
+export function markRaw<T extends object>(
+  value: T
+): T & { [RawSymbol]?: true } {
   def(value, ReactiveFlags.SKIP, true)
   return value
 }

packages/reactivity/src/ref.ts

@@ -12,6 +12,7 @@ import { CollectionTypes } from './collectionHandlers'
 import { createDep, Dep } from './dep'
 
 declare const RefSymbol: unique symbol
+export declare const RawSymbol: unique symbol
 
 export interface Ref<T = any> {
   value: T
@@ -291,6 +292,7 @@ export type UnwrapRefSimple<T> = T extends
   | BaseTypes
   | Ref
   | RefUnwrapBailTypes[keyof RefUnwrapBailTypes]
+  | { [RawSymbol]?: true }
   ? T
   : T extends Array<any>
   ? { [K in keyof T]: UnwrapRefSimple<T[K]> }