flash instance returns middleware directly without executing

.travis.yml

@@ -1,7 +1,9 @@
 node_js:
-- "0.8"
-- "0.10"
-- "0.11"
+- "7"
+- "8"
+- "9"
+- "10"
+- "11"
 language: node_js
 script: "npm run-script test-travis"
 after_script: "npm install coveralls@2 && cat ./coverage/lcov.info | coveralls"

README.md

@@ -13,32 +13,47 @@ The simplest flash implementation for Express.
 ## Usage
 
 ```bash
-npm i flash
+npm install flash
 ```
 
 ```js
-app.use(session()); // session middleware
-app.use(require('flash')());
+let flash = require('flash')
 
-app.use(function (req, res) {
+app.use(session()) // session middleware
+app.use(flash)
+
+app.use(function (req, res, next) {
   // flash a message
-  req.flash('info', 'hello!');
-  next();
+  req.flash('info', 'hello!')
+  next()
 })
 ```
+## Using Pug
 
-```jade
+```pug
 for message in flash
   a.alert(class='alert-' + message.type)
     p= message.message
 ```
 
-```jade
-while message = flash.shift() // consume messages as jade reads them
+Or
+
+```pug
+while message = flash.shift() // consume messages as pug reads them
   a.alert(class='alert-' + message.type)
     p= message.message
 ```
 
+## Using Nunjucks
+
+```nunjucks
+  {% set data = flash.shift() %}
+
+  <div class="card">
+    <p class="text"><strong>{{data.type}}:</strong> {{ data.message }}</p>
+  </div>
+```
+
 ## API
 
 ### req.flash([type], msg)

index.js

@@ -1,32 +1,37 @@
+'use strict'
 
-var assert = require('assert')
-
-module.exports = function () {
-  return function (req, res, next) {
-    assert(req.session, 'a req.session is required!')
+function flash (req, res, next) {
+  // Let's validate that req.session is required
+  if (req.session) {
+    // If session.flash doesn't exists we create a new array
     if (!Array.isArray(req.session.flash)) req.session.flash = []
+
     res.locals.flash = req.session.flash
-    req.flash = res.flash = push
+    req.flash = res.flash = pushMessage
+
     next()
+  } else {
+    let error = new Error('A req.session is required!')
+
+    next(error)
   }
 }
 
-function push(type, msg) {
-  if (!msg) {
-    msg = type
-    type = 'info'
-  }
-  msg = {
-    message: msg,
-    type: type
+function pushMessage (type, message) {
+  let res = this.res || this
+  let messages = res.locals.flash
+  // Let's create a new flash message to push
+  let flashMessage = {
+    type: message ? type : 'info',
+    message: message || type
   }
-  var res = this.res || this
-  var messages = res.locals.flash
+
   // do not allow duplicate flash messages
-  for (var i = 0; i < messages.length; i++) {
-    var message = messages[i]
-    if (msg.type === message.type && msg.message === message.message) return this
-  }
-  messages.push(msg)
+  let msg = messages.find(msg => msg.type === flashMessage.type && msg.message === flashMessage.message)
+  if (msg) return this
+
+  messages.push(flashMessage)
   return this
 }
+
+module.exports = flash