fixed setting locale in request object

README.md

@@ -80,6 +80,8 @@ app.prepare().then(() => {
 })
 ```
 
+> RequestHandler automatically sets req.locale to locale of matched route so you can use it in your app.
+
 Optionally you can pass a custom handler, for example:
 
 ```javascript

src/index.js

@@ -88,6 +88,7 @@ class Routes {
       const {route, query, parsedUrl} = this.match(req.url)
 
       if (route) {
+        req.locale = route.locale
         if (customHandler) {
           customHandler({req, res, route, query})
         } else {

test/index.test.js

@@ -85,6 +85,16 @@ describe('Request handler', () => {
     expect(app.render).toBeCalledWith(req, res, route.page, query)
   })
 
+  test('find route and test locale is set correctly', () => {
+    const routes = nextRoutes()
+    const app = {getRequestHandler: jest.fn(), render: jest.fn()}
+    const req = {url: '/cs/test'}
+
+    routes.add('test', 'cs', '/test')
+    routes.getRequestHandler(app)(req, {})
+    expect(req.locale).toEqual('cs')
+  })
+
   test('find route and call custom handler', () => {
     const {routes, app, req, res} = setup('/en/a')
     const {route, query} = routes.add('a', 'en').match('/en/a')