解决问题---"响应式数据的改变并不会引起watch的触发"

packages/runtime-core/src/apiWatch.ts

@@ -1,4 +1,4 @@
-import { EMPTY_OBJ, hasChanged } from '@vue/shared'
+import { EMPTY_OBJ, hasChanged, isObject } from '@vue/shared'
 import { isReactive, ReactiveEffect } from '@vue/reactivity'
 import { queuePreFlushCb } from '@vue/runtime-core'
 
@@ -28,7 +28,8 @@ function doWatch(
     //todo
     //浅拷贝的形式--指向同样的内存空间
     const baseGetter = getter
-    getter = () => baseGetter()
+    //等同于将source的属性传进去了
+    getter = () => traverse(baseGetter())
   }
 
   let oldValue = {}
@@ -58,3 +59,17 @@ function doWatch(
     effect.stop()
   }
 }
+
+/**
+ * 本质上是拿value, 出发一次getter行为
+ * @param value
+ */
+export function traverse(value: unknown) {
+  if (!isObject(value)) {
+    return value
+  }
+  for (const key in value as object) {
+    traverse((value as object)[key])
+  }
+  return value
+}