feat(ref): 实现 ref 值变化检测和依赖触发功能

- 在 shared 包中新增 hasChanged 函数用于比较值是否发生变化
- 修改 RefImpl 类添加 _rawValue 属性存储原始值
- 实现 ref setter 中的值变化检测逻辑
- 添加 triggerRefValue 函数用于触发 ref 依赖更新
- 优化 ref 的 getter 和 setter 方法实现响应式更新

packages/reactivity/src/ref.ts

@@ -1,6 +1,7 @@
 import { createDep, Dep } from './dep'
 import { toReactive } from './reactive'
-import { activeEffect, track, trackEffects } from './effect'
+import { activeEffect, triggerEffects, trackEffects } from './effect'
+import { hasChanged } from '@vue/shared'
 
 export interface Ref<T = any> {
   value: T
@@ -17,20 +18,36 @@ function createRef(rawValue: unknown, shallow: boolean) {
 }
 class RefImpl<T> {
   private _value: T
+  private _rawValue: T
   public dep?: Dep = undefined
   public readonly __v_isRef = true
   constructor(
     value: T,
     public readonly __v_isShallow: boolean
   ) {
+    this._rawValue = value
     this._value = __v_isShallow ? value : toReactive(value)
   }
   get value() {
     trackRefValue(this)
     return this._value
   }
-  set value(newValue) {}
+  set value(newValue) {
+    if (hasChanged(newValue, this._rawValue)) {
+      this._rawValue = newValue
+      this._value = toReactive(newValue)
+      triggerRefValue(this)
+    }
+  }
 }
+//触发依赖
+export function triggerRefValue(ref) {
+  if (ref.dep) {
+    triggerEffects(ref.dep)
+  }
+}
+
+//收集依赖
 export function trackRefValue(ref) {
   if (activeEffect) {
     trackEffects(ref.dep || (ref.dep = createDep()))

packages/shared/src/index.ts

@@ -3,3 +3,11 @@ export const isArray = Array.isArray
 
 export const isObject = (val: unknown) =>
   val !== null && typeof val === 'object'
+
+/**
+ * 对比两个数据是否发生改变
+ * @param value
+ * @param oldValue
+ */
+export const hasChanged = (value: any, oldValue: any): boolean =>
+  !Object.is(value, oldValue)