回答

Vue 3分离了一个可以在nodejs后端操作的响应式库@vue/reactivity，可直接通过 npm 安装，独立于框架使用。

示例代码

const { reactive, ref, computed, watchEffect } = require('@vue/reactivity')

// 创建响应式对象
const user = reactive({
  name: 'John',
  age: 30,
  address: {
    city: 'New York',
    street: '123 Main St'
  }
})

// 创建响应式原始值
const counter = ref(0)

// 创建计算属性
const fullInfo = computed(() => {
  return `${user.name}, ${user.age}, ${user.address.city}`
})

// 监听响应式数据变化
watchEffect(() => {
  console.log(`[Watcher] User info: ${fullInfo.value}`)
})

watchEffect(() => {
  console.log(`[Watcher] Counter: ${counter.value}`)
})

// 修改响应式数据（会触发 watchers）
user.age = 31
counter.value++

// 嵌套属性修改也会触发响应
user.address.city = 'San Francisco'

// 计算属性会自动更新
console.log(`Full info: ${fullInfo.value}`)

// 输出:
// [Watcher] User info: John, 30, New York
// [Watcher] Counter: 0
// [Watcher] User info: John, 31, New York
// [Watcher] Counter: 1
// [Watcher] User info: John, 31, San Francisco
// Full info: John, 31, San Francisco