From da613dd71341a84180e04f258224475944e5d2e6 Mon Sep 17 00:00:00 2001
From: Rui Martins <rmartins90@users.noreply.github.com>
Date: Tue, 18 Oct 2022 14:59:22 +0100
Subject: [PATCH 1/2] chore: warn developers for duplicated store keys

---
 packages/pinia/__tests__/store.spec.ts | 14 +++++++++++++-
 packages/pinia/src/createPinia.ts      |  1 +
 packages/pinia/src/rootStore.ts        |  8 ++++++++
 packages/pinia/src/store.ts            |  8 ++++++++
 4 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/packages/pinia/__tests__/store.spec.ts b/packages/pinia/__tests__/store.spec.ts
index 4e0a21ad7e..259b17e02c 100644
--- a/packages/pinia/__tests__/store.spec.ts
+++ b/packages/pinia/__tests__/store.spec.ts
@@ -101,7 +101,7 @@ describe('Store', () => {
 
   it('can create an empty state if no state option is provided', () => {
     const store = defineStore({ id: 'some' })()
-
+    
     expect(store.$state).toEqual({})
   })
 
@@ -379,4 +379,16 @@ describe('Store', () => {
       `[🍍]: A getter cannot have the same name as another state property. Rename one of them. Found with "anyName" in store "main".`
     ).toHaveBeenWarnedTimes(1)
   })
+
+  it.only('warns when creating store with existing id', async () => {
+    const storeId = 'testStoreID';
+    const useFirstStore = defineStore(storeId, {});
+    const useSecondStore = defineStore(storeId, {});
+    useFirstStore();
+    useSecondStore();
+
+    expect(
+      `[🍍]: Stores should have unique identifiers. Found multiple stores with id "testStoreID". Rename one of them.`
+    ).toHaveBeenWarned();
+  });
 })
diff --git a/packages/pinia/src/createPinia.ts b/packages/pinia/src/createPinia.ts
index f71497fd31..90253bc3df 100644
--- a/packages/pinia/src/createPinia.ts
+++ b/packages/pinia/src/createPinia.ts
@@ -52,6 +52,7 @@ export function createPinia(): Pinia {
     _a: null,
     _e: scope,
     _s: new Map<string, StoreGeneric>(),
+    _k: [],
     state,
   })
 
diff --git a/packages/pinia/src/rootStore.ts b/packages/pinia/src/rootStore.ts
index 0509a5c8eb..9bbd3fa21e 100644
--- a/packages/pinia/src/rootStore.ts
+++ b/packages/pinia/src/rootStore.ts
@@ -85,6 +85,14 @@ export interface Pinia {
    */
   _s: Map<string, StoreGeneric>
 
+  /**
+   * Registry of store ids defined in this pinia instance.
+   * This is used to check for duplicated keys.
+   * 
+   * @internal
+   */
+  _k: Array<string>
+
   /**
    * Added by `createTestingPinia()` to bypass `useStore(pinia)`.
    *
diff --git a/packages/pinia/src/store.ts b/packages/pinia/src/store.ts
index 98d77a2666..4504ee2127 100644
--- a/packages/pinia/src/store.ts
+++ b/packages/pinia/src/store.ts
@@ -880,6 +880,14 @@ export function defineStore(
     id = idOrOptions.id
   }
 
+  // Warn developers about existing store ID in dev environments
+  if (__DEV__ && activePinia?._k.includes(id)) {
+    console.warn(`[🍍]: Stores should have unique identifiers. Found multiple stores with id "${id}". Rename one of them.`)
+  }
+
+  // Push ID to keys registry
+  activePinia?._k.push(id)
+
   function useStore(pinia?: Pinia | null, hot?: StoreGeneric): StoreGeneric {
     const currentInstance = getCurrentInstance()
     pinia =

From fbfc8304c4e62165a8bd5fd061fbb23a44a90863 Mon Sep 17 00:00:00 2001
From: Rui Martins <rmartins90@users.noreply.github.com>
Date: Tue, 18 Oct 2022 15:09:16 +0100
Subject: [PATCH 2/2] chore: remove "only" keyword on test

---
 packages/pinia/__tests__/store.spec.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/pinia/__tests__/store.spec.ts b/packages/pinia/__tests__/store.spec.ts
index 259b17e02c..cef8262448 100644
--- a/packages/pinia/__tests__/store.spec.ts
+++ b/packages/pinia/__tests__/store.spec.ts
@@ -101,7 +101,7 @@ describe('Store', () => {
 
   it('can create an empty state if no state option is provided', () => {
     const store = defineStore({ id: 'some' })()
-    
+
     expect(store.$state).toEqual({})
   })
 
@@ -380,7 +380,7 @@ describe('Store', () => {
     ).toHaveBeenWarnedTimes(1)
   })
 
-  it.only('warns when creating store with existing id', async () => {
+  it('warns when creating store with existing id', async () => {
     const storeId = 'testStoreID';
     const useFirstStore = defineStore(storeId, {});
     const useSecondStore = defineStore(storeId, {});