fix: reference the store directly in storeToRefs to ensure correct reactivity after HMR (#2795)

Author: babu-ch

packages/pinia/__tests__/storeToRefs.spec.ts

@@ -1,6 +1,7 @@
 import { describe, beforeEach, it, expect } from 'vitest'
 import { computed, reactive, ref, ToRefs } from 'vue'
 import { createPinia, defineStore, setActivePinia, storeToRefs } from '../src'
+import { set } from 'vue-demi'
 
 describe('storeToRefs', () => {
   beforeEach(() => {
@@ -170,6 +171,25 @@ describe('storeToRefs', () => {
     expect(refs.n.value).toBe(2)
   })
 
+  it('keep reactivity', () => {
+    const store = defineStore('a', () => {
+      const n = ref(0)
+      const double = computed(() => n.value * 2)
+      return { n, double }
+    })()
+
+    const { double } = storeToRefs(store)
+
+    // Assuming HMR operation
+    set(
+      store,
+      'double',
+      computed(() => 1)
+    )
+
+    expect(double.value).toEqual(1)
+  })
+
   tds(() => {
     const store1 = defineStore('a', () => {
       const n = ref(0)

packages/pinia/src/storeToRefs.ts

@@ -94,11 +94,11 @@ export function storeToRefs<SS extends StoreGeneric>(
     // @ts-expect-error: toRefs include methods and others
     return toRefs(store)
   } else {
-    store = toRaw(store)
+    const rawStore = toRaw(store)
 
     const refs = {} as StoreToRefs<SS>
-    for (const key in store) {
-      const value = store[key]
+    for (const key in rawStore) {
+      const value = rawStore[key]
       if (isRef(value) || isReactive(value)) {
         // @ts-expect-error: the key is state or getter
         refs[key] =