swappableMux is now public and Append() now updates Server.Handler

Co-authored-by: Roberto Abdelkader Martínez Pérez <robertomartinezp@gmail.com>

internal/server/user/server_test.go

@@ -1,3 +1,41 @@
 package user
 
+import (
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"testing"
+
+	"github.com/BBVA/kapow/internal/server/model"
+	"github.com/BBVA/kapow/internal/server/user/mux"
+)
+
 // TODO TestRunRunsAnHTTPServer(t *testing.T) {}
+
+func TestAppendUpdatesMuxWithProvideRoute(t *testing.T) {
+	Server = http.Server{
+		Handler: mux.New(),
+	}
+	srl := New()
+	route := model.Route{
+		Method:     "GET",
+		Pattern:    "/",
+		Entrypoint: "/bin/sh -c",
+		Command:    "jaillover > /tmp/kapow-test-append-updates-mux",
+	}
+	os.Remove("/tmp/kapow-test-append-updates-mux")
+	defer os.Remove("/tmp/kapow-test-append-updates-mux")
+
+	srl.Append(route)
+
+	req := httptest.NewRequest("GET", "/", nil)
+	w := httptest.NewRecorder()
+
+	Server.Handler.ServeHTTP(w, req)
+
+	if _, err := os.Stat("/tmp/kapow-test-append-updates-mux"); os.IsNotExist(err) {
+		t.Error("Routes not updated")
+	} else if err != nil {
+		t.Fatalf("Unexpected error: %v", err)
+	}
+}