Function mergeProps

packages/runtime-core/src/vnode.ts:877–914

(...args: (Data & VNodeProps)[])

}

export function mergeProps(...args: (Data & VNodeProps)[]): Data {
  const ret: Data = {}
  for (let i = 0; i < args.length; i++) {
    const toMerge = args[i]
    for (const key in toMerge) {
      if (key === 'class') {
        if (ret.class !== toMerge.class) {
          ret.class = normalizeClass([ret.class, toMerge.class])
        }
      } else if (key === 'style') {
        ret.style = normalizeStyle([ret.style, toMerge.style])
      } else if (isOn(key)) {
        const existing = ret[key]
        const incoming = toMerge[key]
        if (
          incoming &&
          existing !== incoming &&
          !(isArray(existing) && existing.includes(incoming))
        ) {
          ret[key] = existing
            ? [].concat(existing as any, incoming as any)
            : incoming
        } else if (
          incoming == null &&
          existing == null &&
          // mergeProps({ 'onUpdate:modelValue': undefined }) should not retain
          // the model listener.
          !isModelListener(key)
        ) {
          ret[key] = incoming
        }
      } else if (key !== '') {
        ret[key] = toMerge[key]
      }
    }
  }
  return ret
}

export function invokeVNodeHook(
  hook: VNodeHook,