fix: lowercasing incoming request headers

closes antongolub#33

- Makes sure incoming header options are always lowercased. This behavior would be the same as in original express request.

src/main/js/request.js

@@ -23,7 +23,8 @@ import url from 'url'
 import {
   assign,
   setprototypeof,
-  appendAdditionalProps
+  appendAdditionalProps,
+  convertKeysToLowerCase
 } from './util'
 import DEFAULT_APP from './app'
 
@@ -74,7 +75,7 @@ export default class Request implements IRequest {
     this.socket = opts.socket
     this.app = opts.app
     this.res = opts.res
-    this.headers = opts.headers
+    this.headers = opts.headers ? convertKeysToLowerCase(opts.headers) : {}
     this.body = opts.body
     this.params = opts.params
     this.connection = opts.connection

src/test/js/request.js

@@ -47,6 +47,13 @@ describe('request', () => {
         expect(req.header('foo')).toBe('bar')
         expect(req.get('BAZ')).toBe('qux')
       })
+
+      it('lowercases incoming headers', () => {
+        const req = new Request({ headers: { 'BaZ-Header': 'qux' } })
+
+        expect(req.get('Baz-Header')).toBe('qux')
+        expect(req.headers['baz-header']).toBe('qux')
+      })
     })
 
     describe('ip', () => {