message: fix: allow _ in watch paths (element compat)
diff: @@ -30,7 +30,7 @@ export function def (obj: Object, key: string, val: any, enumerable?: boolean) {
  /**
  * Parse simple path.
  */
  -const bailRE = new RegExp(`[^${unicodeLetters}.$]`)
  +const bailRE = new RegExp(`[^${unicodeLetters}.$_]`)
  export function parsePath (path: string): any {
  if (bailRE.test(path)) {
  return
  