tests: added mock data sources to go backend

backend-go/internal/application/services/user_service_test.go

@@ -0,0 +1,23 @@
+package services_test
+
+import "testing"
+
+
+func TestCreateUserService(t *testing.T) {
+	mockRepo := mocks.NewMockUserRepository()
+	service := services.NewUserService(mockRepo)
+
+	user := entities.UserCreate{
+		Email:    "service@test.com",
+		Name:     "Jane Doe",
+		Password: "securepassword",
+	}
+
+	result := service.CreateUser(context.Background(), user)
+
+	assert.True(t, result.IsRight(), "Expected service to create user")
+	result.Map(func(user entities.User) {
+		assert.Equal(t, "service@test.com", user.Email)
+		assert.Equal(t, "Jane Doe", user.Name)
+	})
+}