WIP feat: access namespaced getters using the dot notation

src/store.js

@@ -237,6 +237,12 @@ function resetStoreVM (store, state, hot) {
       enumerable: true // for local getters
     })
   })
+  // map namespaced getters - computed object needs to be complete
+  forEachValue(wrappedGetters, (fn, key) => {
+    if (key.includes('/')) {
+      mapNamespacedGetter(store.getters, key, computed[key], computed)
+    }
+  })
 
   // use a Vue instance to store the state tree
   // suppress warnings just in case the user has added
@@ -452,6 +458,34 @@ function getNestedState (state, path) {
     : state
 }
 
+function mapNamespacedGetter (gettersObject, path, getterFunction, computed) {
+  const sections = path.split('/')
+  // If there is a getter registered in the root namespace with the name of the module
+  // don't map the namespaced getters to avoid breaking changes.
+  // A warning should be thrown in this case.
+  if (computed[sections[0]]) {
+    console.warn(
+      `[vuex] "${sections[0]}" module's getters are not available under the dot-notation because there is a getter in the root namespace with the same name ("${sections[0]}").`,
+      `If you want to use the dot-notation rename the "${sections[0]}" root getter or the module.`
+    )
+    return
+  }
+  sections.forEach((section, index) => {
+    // if it's the value AKA the last element of the array
+    if (index === sections.length - 1) {
+      Object.defineProperty(gettersObject, section, {
+        get: getterFunction,
+        enumerable: true
+      })
+    } else {
+      if (!gettersObject[section]) {
+        gettersObject[section] = {}
+      }
+      gettersObject = gettersObject[section]
+    }
+  })
+}
+
 function unifyObjectStyle (type, payload, options) {
   if (isObject(type) && type.type) {
     options = payload

test/unit/modules.spec.js

@@ -547,6 +547,101 @@ describe('Modules', () => {
       store.dispatch('parent/test')
     })
 
+    it('module: prefer root getter when there is a module with the same name', () => {
+      const store = new Vuex.Store({
+        state: {},
+        getters: {
+          users () {
+            return 'root users'
+          }
+        },
+        modules: {
+          users: {
+            namespaced: true
+          }
+        }
+      })
+      expect(store.getters.users).toBe('root users')
+    })
+
+    it('module: warn when root getter has the same name with a namespaced module', () => {
+      spyOn(console, 'warn')
+      new Vuex.Store({
+        getters: {
+          users () {
+            return 'root users'
+          }
+        },
+        modules: {
+          users: {
+            namespaced: true,
+            getters: {
+              users () {
+                return 'module users'
+              }
+            }
+          }
+        }
+      })
+      expect(console.warn).toHaveBeenCalledWith(
+        `[vuex] "users" module's getters are not available under the dot-notation because there is a getter in the root namespace with the same name ("users").`,
+        `If you want to use the dot-notation rename the "users" root getter or the module.`
+      )
+    })
+
+    it('module: access namespaced getters with a dot', () => {
+      const store = new Vuex.Store({
+        modules: {
+          a: {
+            namespaced: true,
+            state: () => ({ x: 1 }),
+            mutations: {
+              incX: state => state.x++
+            },
+            getters: {
+              twiceX: state => state.x * 2
+            },
+            modules: {
+              b: {
+                state: () => ({ y: 10 }),
+                mutations: {
+                  incY: state => state.y++
+                },
+                getters: {
+                  twiceY: state => state.y * 2
+                }
+              },
+              c: {
+                namespaced: true,
+                state: () => ({ z: 100 }),
+                mutations: {
+                  incZ: state => state.z++
+                },
+                getters: {
+                  twiceZ: state => state.z * 2
+                }
+              }
+            }
+          }
+        }
+      })
+
+      // root > namespaced
+      expect(store.getters.a.twiceX).toBe(2)
+      store.commit('a/incX')
+      expect(store.getters.a.twiceX).toBe(4)
+
+      // root > namespaced > not namespaced
+      expect(store.getters.a.twiceY).toBe(20)
+      store.commit('a/incY')
+      expect(store.getters.a.twiceY).toBe(22)
+
+      // root > namespaced > namespaced
+      expect(store.getters.a.c.twiceZ).toBe(200)
+      store.commit('a/c/incZ')
+      expect(store.getters.a.c.twiceZ).toBe(202)
+    })
+
     it('dispatching multiple actions in different modules', done => {
       const store = new Vuex.Store({
         modules: {