feat(shared): support Map and Set in toDisplayString

close #1067, close #1100

packages/shared/src/index.ts

@@ -11,6 +11,7 @@ export * from './domTagConfig'
 export * from './domAttrConfig'
 export * from './escapeHtml'
 export * from './looseEqual'
+export * from './toDisplayString'
 
 export const EMPTY_OBJ: { readonly [key: string]: any } = __DEV__
   ? Object.freeze({})
@@ -112,15 +113,6 @@ export const capitalize = cacheStringFunction(
 export const hasChanged = (value: any, oldValue: any): boolean =>
   value !== oldValue && (value === value || oldValue === oldValue)
 
-// For converting {{ interpolation }} values to displayed strings.
-export const toDisplayString = (val: unknown): string => {
-  return val == null
-    ? ''
-    : isArray(val) || (isPlainObject(val) && val.toString === objectToString)
-      ? JSON.stringify(val, null, 2)
-      : String(val)
-}
-
 export const invokeArrayFns = (fns: Function[], arg?: any) => {
   for (let i = 0; i < fns.length; i++) {
     fns[i](arg)