Reformated/commented for clarity

lib/app/store.js

@@ -42,30 +42,33 @@ if (typeof storeData !== 'function') {
       continue
     }
 
-    //if file is user/index.js
+    //if file is foo/index.js
-    //it should save as user
+    //it should save as foo
-    var isIndex = (name === 'index')
+    let isIndex = (name === 'index')
     if (isIndex)
       namePath.pop()
 
     let module      = getModuleNamespace(storeData, namePath)
+    let fileModule  = getModule(filename)
     name = namePath.pop()
     module[name] = module[name] || {}
-    var fileModule = getModule(filename)
 
+    //if file is foo.js, existing properties take priority
+    //because it's the least specific case
     if (!isIndex) {
       module[name] = Object.assign({}, fileModule, module[name])
       module[name].namespaced = true
       continue
     }
 
+    //if file is foo/index.js we want to overwrite properties from foo.js
+    //but not from appended mods like foo/actions.js
     var appendedMods = []
     if (module[name].appends) {
       fileModule.appends = module[name].appends
-      for (let append of module[name].appends) {
+      for (let append of module[name].appends)
         appendedMods[append] = module[name][append]
     }
-    }
     module[name] = Object.assign(module[name], fileModule, appendedMods)
   }