Function invokeDirectiveHook

packages/runtime-core/src/directives.ts:170–200

(
  vnode: VNode,
  prevVNode: VNode | null,
  instance: ComponentInternalInstance | null,
  name: keyof ObjectDirective,
)

}

export function invokeDirectiveHook(
  vnode: VNode,
  prevVNode: VNode | null,
  instance: ComponentInternalInstance | null,
  name: keyof ObjectDirective,
): void {
  const bindings = vnode.dirs!
  const oldBindings = prevVNode && prevVNode.dirs!
  for (let i = 0; i < bindings.length; i++) {
    const binding = bindings[i]
    if (oldBindings) {
      binding.oldValue = oldBindings[i].value
    }
    let hook = binding.dir[name] as DirectiveHook | DirectiveHook[] | undefined
    if (__COMPAT__ && !hook) {
      hook = mapCompatDirectiveHook(name, binding.dir, instance)
    }
    if (hook) {
      // disable tracking inside all lifecycle hooks
      // since they can potentially be called inside effects.
      pauseTracking()
      callWithAsyncErrorHandling(hook, instance, ErrorCodes.DIRECTIVE_HOOK, [
        vnode.el,
        binding,
        vnode,
        prevVNode,
      ])
      resetTracking()
    }
  }
}