Merge pull request #181 from Juanmcuello/json-body-parser-fix

Rack::JSONBodyParser. Do not rescue JSON:ParserError

Author: andrykonchin

lib/rack/contrib/json_body_parser.rb

@@ -55,16 +55,18 @@ def initialize(
     end
 
     def call(env)
-      if @verbs.include?(env[Rack::REQUEST_METHOD]) &&
-         @matcher.call(@media, env['CONTENT_TYPE'])
+      begin
+        if @verbs.include?(env[Rack::REQUEST_METHOD]) &&
+           @matcher.call(@media, env['CONTENT_TYPE'])
 
-        update_form_hash_with_json_body(env)
+          update_form_hash_with_json_body(env)
+        end
+      rescue JSON::ParserError
+        body = { error: 'Failed to parse body as JSON' }.to_json
+        header = { 'Content-Type' => 'application/json' }
+        return Rack::Response.new(body, 400, header).finish
       end
       @app.call(env)
-    rescue JSON::ParserError
-      body = { error: 'Failed to parse body as JSON' }.to_json
-      header = { 'Content-Type' => 'application/json' }
-      Rack::Response.new(body, 400, header).finish
     end
 
     private

test/spec_rack_json_body_parser_spec.rb

@@ -66,6 +66,12 @@ def create_parser(app, **args, &block)
     _(result).must_be_empty
   end
 
+  specify "should not rescue JSON:ParserError raised by the app" do
+    env = mock_env
+    app = ->(env) { raise JSON::ParserError }
+    _( -> { create_parser(app).call(env) }).must_raise JSON::ParserError
+  end
+
   describe "contradiction between body and type" do
     specify "should return bad request with a JSON-encoded error message" do
       env = mock_env(input: 'This is not JSON')