Add unit test for returning headers

Signed-off-by: Alex Ellis <alexellis2@gmail.com>

auth/basic-auth/main.go

@@ -60,9 +60,20 @@ func makeLogger(next http.Handler) func(w http.ResponseWriter, r *http.Request)
 		next.ServeHTTP(rr, r)
 		log.Printf("Validated request %d.\n", rr.Code)
 
+		resHeader := rr.Header()
+		copyHeaders(w.Header(), &resHeader)
+
 		w.WriteHeader(rr.Code)
 		if rr.Body != nil {
 			w.Write(rr.Body.Bytes())
 		}
 	}
 }
+
+func copyHeaders(destination http.Header, source *http.Header) {
+	for k, v := range *source {
+		vClone := make([]string, len(v))
+		copy(vClone, v)
+		(destination)[k] = vClone
+	}
+}

auth/basic-auth/main_test.go

@@ -0,0 +1,29 @@
+package main
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func Test_makeLogger(t *testing.T) {
+	handler := http.HandlerFunc(makeLogger(http.HandlerFunc(
+		func(w http.ResponseWriter, r *http.Request) {
+			w.Header().Set("X-Unit-Test", "true")
+		})))
+
+	s := httptest.NewServer(handler)
+	defer s.Close()
+
+	req := httptest.NewRequest(http.MethodGet, s.URL, nil)
+	rr := httptest.NewRecorder()
+
+	handler.ServeHTTP(rr, req)
+
+	got := rr.Header().Get("X-Unit-Test")
+	want := "true"
+	if want != got {
+		t.Errorf("Header X-Unit-Test, want: %s, got %s", want, got)
+	}
+
+}