fix(watch): deep watching symbol properties

packages/runtime-core/__tests__/apiWatch.spec.ts

@@ -932,6 +932,52 @@ describe('api: watch', () => {
  expect(dummy).toEqual([1, 2])
  })
 
+ it('deep with symbols', async () => {
+ const symbol1 = Symbol()
+ const symbol2 = Symbol()
+ const symbol3 = Symbol()
+ const symbol4 = Symbol()
+
+ const raw: any = {
+ [symbol1]: {
+ [symbol2]: 1,
+ },
+ }
+
+ Object.defineProperty(raw, symbol3, {
+ writable: true,
+ enumerable: false,
+ value: 1,
+ })
+
+ const state = reactive(raw)
+ const spy = vi.fn()
+
+ watch(() => state, spy, { deep: true })
+
+ await nextTick()
+ expect(spy).toHaveBeenCalledTimes(0)
+
+ state[symbol1][symbol2] = 2
+ await nextTick()
+ expect(spy).toHaveBeenCalledTimes(1)
+
+ // Non-enumerable properties don't trigger deep watchers
+ state[symbol3] = 3
+ await nextTick()
+ expect(spy).toHaveBeenCalledTimes(1)
+
+ // Adding a new symbol property
+ state[symbol4] = 1
+ await nextTick()
+ expect(spy).toHaveBeenCalledTimes(2)
+
+ // Removing a symbol property
+ delete state[symbol4]
+ await nextTick()
+ expect(spy).toHaveBeenCalledTimes(3)
+ })
+
  it('immediate', async () => {
  const count = ref(0)
  const cb = vi.fn()

packages/runtime-core/src/apiWatch.ts

@@ -493,6 +493,11 @@ export function traverse(
  for (const key in value) {
  traverse(value[key], depth, seen)
  }
+ for (const key of Object.getOwnPropertySymbols(value)) {
+ if (Object.prototype.propertyIsEnumerable.call(value, key)) {
+ traverse(value[key as any], depth, seen)
+ }
+ }
  }
  return value
 }