Fix #14: Middleware hangs if rawBody is already parsed

README.md

@@ -36,11 +36,33 @@ alexaRouter.get('/weather_info', function(req, res) { ... })
 app.listen(3000)
 ```
 
+### Common errors
+* `The raw request body has already been parsed.`- This means that you're probably using one of the body-parser middlewares and it is loaded before this one. To fix it, you should load the body-parsers **after** this one.
+
+Before:
+```javascript
+var alexaRouter = express.Router()
+app.use('/alexa', alexaRouter)
+
+// INCORRECT
+alexaRouter.use(bodyParser.json());
+alexaRouter.use(verifier)
+```
+
+After:
+```javascript
+var alexaRouter = express.Router()
+app.use('/alexa', alexaRouter)
+
+// CORRECT
+alexaRouter.use(verifier)
+alexaRouter.use(bodyParser.json());
+```
 
 ### Mentions
 * [mreinstein](https://github.com/mreinstein) for his [alexa-verifier](https://github.com/alexa-js/alexa-verifier) module, which allows you to verify any Amazon requests from any web service
 
 ### License
 Copyright (c) 2016-2017 Tejas Shah
 
-MIT License, see [LICENSE](https://tejashah88.mit-license.org/2016-2017) for details.
+MIT License, see [LICENSE](https://tejashah88.mit-license.org/2016-2017) for details.

index.js

@@ -7,8 +7,8 @@ var verifier = require('alexa-verifier')
 // text string, and set a flag on the request object so other body parser
 // middlewares don't try to parse the body again
 module.exports = function alexaVerifierMiddleware(req, res, next) {
-  if (req._body && (typeof req.rawBody !== 'string')) {
-    var er = 'The raw request body is not available.'
+  if (req._body) {
+    var er = 'The raw request body has already been parsed.'
     return res.status(400).json({ status: 'failure', reason: er })
   }
 

test/index.js

@@ -54,7 +54,7 @@ test('fail if request body is already parsed', function(t) {
 
   t.equal(mockRes.statusCode, 400);
   t.deepEqual(JSON.parse(mockRes._getData()), {
-    reason: 'The raw request body is not available.',
+    reason: 'The raw request body has already been parsed.',
     status: 'failure'
   });