fix(core): typing of key in VNodeProps (#4242)

close #4240

Author: AlexandraCaragata

packages/runtime-core/src/components/KeepAlive.ts

@@ -46,7 +46,7 @@ export interface KeepAliveProps {
   max?: number | string
 }
 
-type CacheKey = string | number | ConcreteComponent
+type CacheKey = string | number | symbol | ConcreteComponent
 type Cache = Map<CacheKey, VNode>
 type Keys = Set<CacheKey>
 

packages/runtime-core/src/renderer.ts

@@ -1873,7 +1873,7 @@ function baseCreateRenderer(
       const s2 = i // next starting index
 
       // 5.1 build key:index map for newChildren
-      const keyToNewIndexMap: Map<string | number, number> = new Map()
+      const keyToNewIndexMap: Map<string | number | symbol, number> = new Map()
       for (i = s2; i <= e2; i++) {
         const nextChild = (c2[i] = optimized
           ? cloneIfMounted(c2[i] as VNode)

packages/runtime-core/src/vnode.ts

@@ -90,7 +90,7 @@ export type VNodeHook =
 
 // https://github.com/microsoft/TypeScript/issues/33099
 export type VNodeProps = {
-  key?: string | number
+  key?: string | number | symbol
   ref?: VNodeRef
 
   // vnode hooks
@@ -138,7 +138,7 @@ export interface VNode<
 
   type: VNodeTypes
   props: (VNodeProps & ExtraProps) | null
-  key: string | number | null
+  key: string | number | symbol | null
   ref: VNodeNormalizedRef | null
   /**
    * SFC only. This is assigned on vnode creation using currentScopeId