Changes how #body_params determines the length of the request

Author: adamgotterer

CHANGELOG.markdown

@@ -1,6 +1,7 @@
 Next Release
 ============
 
+* [#210](https://github.com/intridea/grape/pull/210): Fix: `Endpoint#body_params` causing undefined method 'size' - [@adamgotterer](https://github.com/adamgotterer).
 * [#201](https://github.com/intridea/grape/pull/201): Rewritten `params` DSL, including support for coercion and validations - [@schmurfy](https://github.com/schmurfy).
 * [#205](https://github.com/intridea/grape/pull/205): Fix: Corrected parsing of empty JSON body on POST/PUT - [@tim-vandecasteele](https://github.com/tim-vandecasteele).
 * [#181](https://github.com/intridea/grape/pull/181): Fix: Corrected JSON serialization of nested hashes containing `Grape::Entity` instances - [@benrosenblum](https://github.com/benrosenblum).

lib/grape/endpoint.rb

@@ -125,7 +125,7 @@ def params
 
     # Pull out request body params if the content type matches and we're on a POST or PUT
     def body_params
-      if ['POST', 'PUT'].include?(request.request_method.to_s.upcase) && request.body.size > 0
+      if ['POST', 'PUT'].include?(request.request_method.to_s.upcase) && request.content_length.to_i > 0
         return case env['CONTENT_TYPE']
           when 'application/json'
             MultiJson.decode(request.body.read)