refactor handler out

src/cmd/server/handler/handler_test.go

@@ -0,0 +1,21 @@
+package handler_test
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"show-rss/src/cmd/server/handler"
+	"show-rss/src/db"
+	"testing"
+)
+
+func TestHandler(t *testing.T) {
+	h := handler.New(db.Test(t, context.Background()))
+
+	w := httptest.NewRecorder()
+	r := httptest.NewRequest(http.MethodGet, "/not-found", nil)
+	h.ServeHTTP(w, r)
+	if w.Code != http.StatusNotFound {
+		t.Errorf("%+v", w)
+	}
+}