From db96c4556df31619eda87e4b5f3e8b737429707a Mon Sep 17 00:00:00 2001
From: Denis Karabaza <denis.karabaza@gmail.com>
Date: Fri, 3 Aug 2018 21:51:52 +0200
Subject: [PATCH 1/2] feat: warn about conflicts between state and module

---
 src/store.js              |  7 +++++++
 test/unit/modules.spec.js | 18 ++++++++++++++++++
 2 files changed, 25 insertions(+)

diff --git a/src/store.js b/src/store.js
index b5b083c92..5cb2ff5b3 100644
--- a/src/store.js
+++ b/src/store.js
@@ -282,6 +282,13 @@ function installModule (store, rootState, path, module, hot) {
     const parentState = getNestedState(rootState, path.slice(0, -1))
     const moduleName = path[path.length - 1]
     store._withCommit(() => {
+      if (process.env.NODE_ENV !== 'production') {
+        if (moduleName in parentState) {
+          console.warn(
+            `[vuex] state field "${moduleName}" was overridden by a module with the same name`
+          )
+        }
+      }
       Vue.set(parentState, moduleName, module.state)
     })
   }
diff --git a/test/unit/modules.spec.js b/test/unit/modules.spec.js
index bc8fa2247..8ba9d24fc 100644
--- a/test/unit/modules.spec.js
+++ b/test/unit/modules.spec.js
@@ -547,6 +547,24 @@ describe('Modules', () => {
       store.dispatch('parent/test')
     })
 
+    it('module: warn when module overrides state', () => {
+      spyOn(console, 'warn')
+      const store = new Vuex.Store({
+        state () {
+          return { value: 1 }
+        },
+        modules: {
+          value: {
+            state: () => 2
+          }
+        }
+      })
+      expect(store.state.value).toBe(2)
+      expect(console.warn).toHaveBeenCalledWith(
+        `[vuex] state field "value" was overridden by a module with the same name`
+      )
+    })
+
     it('dispatching multiple actions in different modules', done => {
       const store = new Vuex.Store({
         modules: {

From 4e252745a41e2a92fd94399b59891c8aeab40d25 Mon Sep 17 00:00:00 2001
From: ktsn <ktsn55@gmail.com>
Date: Sun, 10 Nov 2019 22:14:43 +0800
Subject: [PATCH 2/2] fix: show module path when it overwrite a state field

---
 src/store.js              |  2 +-
 test/unit/modules.spec.js | 18 +++++++++++-------
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/src/store.js b/src/store.js
index 5cb2ff5b3..b30e0d31a 100644
--- a/src/store.js
+++ b/src/store.js
@@ -285,7 +285,7 @@ function installModule (store, rootState, path, module, hot) {
       if (process.env.NODE_ENV !== 'production') {
         if (moduleName in parentState) {
           console.warn(
-            `[vuex] state field "${moduleName}" was overridden by a module with the same name`
+            `[vuex] state field "${moduleName}" was overridden by a module with the same name at "${path.join('.')}"`
           )
         }
       }
diff --git a/test/unit/modules.spec.js b/test/unit/modules.spec.js
index 8ba9d24fc..bc34ae1e6 100644
--- a/test/unit/modules.spec.js
+++ b/test/unit/modules.spec.js
@@ -550,18 +550,22 @@ describe('Modules', () => {
     it('module: warn when module overrides state', () => {
       spyOn(console, 'warn')
       const store = new Vuex.Store({
-        state () {
-          return { value: 1 }
-        },
         modules: {
-          value: {
-            state: () => 2
+          foo: {
+            state () {
+              return { value: 1 }
+            },
+            modules: {
+              value: {
+                state: () => 2
+              }
+            }
           }
         }
       })
-      expect(store.state.value).toBe(2)
+      expect(store.state.foo.value).toBe(2)
       expect(console.warn).toHaveBeenCalledWith(
-        `[vuex] state field "value" was overridden by a module with the same name`
+        `[vuex] state field "value" was overridden by a module with the same name at "foo.value"`
       )
     })