[hw-1] implement cart service

cart/internal/app/server/error_response.go

@@ -0,0 +1,24 @@
+package server
+
+import (
+	"encoding/json"
+	"net/http"
+
+	"github.com/rs/zerolog/log"
+)
+
+func makeErrorResponse(w http.ResponseWriter, err error, statusCode int) {
+	type ErrorMessage struct {
+		Message string
+	}
+
+	w.Header().Add("Content-Type", "application/json")
+	w.WriteHeader(statusCode)
+
+	errResponse := &ErrorMessage{Message: err.Error()}
+	if errE := json.NewEncoder(w).Encode(errResponse); errE != nil {
+		log.Err(errE).Send()
+
+		return
+	}
+}