Added server tests

Server.go

@@ -18,7 +18,7 @@ import (
 // Server is the interface for an HTTP server.
 type Server interface {
 	Get(path string, handler Handler)
-	Request(method string, path string, body io.Reader) Response
+	Request(method string, path string, headers []Header, body io.Reader) Response
 	Router() *router.Router[Handler]
 	Run(address string) error
 	Use(handlers ...Handler)
@@ -67,8 +67,9 @@ func (s *server) Get(path string, handler Handler) {
 // Request performs a synthetic request and returns the response.
 // This function keeps the response in memory so it's slightly slower than a real request.
 // However it is very useful inside tests where you don't want to spin up a real web server.
-func (s *server) Request(method string, url string, body io.Reader) Response {
+func (s *server) Request(method string, url string, headers []Header, body io.Reader) Response {
 	ctx := s.newContext()
+	ctx.request.headers = headers
 	s.handleRequest(ctx, method, url, io.Discard)
 	return ctx.Response()
 }
@@ -178,7 +179,7 @@ func (s *server) handleConnection(conn net.Conn) {
 			key := message[:colon]
 			value := message[colon+2 : len(message)-2]
 
-			ctx.request.headers = append(ctx.request.headers, header{
+			ctx.request.headers = append(ctx.request.headers, Header{
 				Key:   key,
 				Value: value,
 			})
@@ -219,12 +220,12 @@ func (s *server) newContext() *context {
 		request: request{
 			reader:  bufio.NewReader(nil),
 			body:    make([]byte, 0),
-			headers: make([]header, 0, 8),
+			headers: make([]Header, 0, 8),
 			params:  make([]router.Parameter, 0, 8),
 		},
 		response: response{
 			body:    make([]byte, 0, 1024),
-			headers: make([]header, 0, 8),
+			headers: make([]Header, 0, 8),
 			status:  200,
 		},
 	}