【テストコードの実装】Go言語でのAPI開発 | 実践的な学習から実装まで⑥

package repository

import (
	"database/sql"
	"myApiProject/internal/domain"
	"strconv"
	"strings"
)

// 下のインフェースを追加
type UserRepository interface {
	FindByID(userID string) (*domain.User, error)
	UpdateUser(userRes domain.User) (string, error)
	GetUserDetails(userID string) (*domain.User, error)
}

// type名のプレフィックスを小文字に変更
type userRepository struct {
	db *sql.DB
}

// returnのプレフィックスを小文字に変更
func NewUserRepository(db *sql.DB) UserRepository {
	return &userRepository{db}
}

// 引数の型のプレフィックスを小文字に変更
func (r *userRepository) FindByID(userID string) (*domain.User, error) {
	user := &domain.User{}
	err := r.db.QueryRow("SELECT user_id, name, email, password FROM Users WHERE user_id = ?", userID).Scan(&user.UserID, &user.Name, &user.Email, &user.Password)
	if err != nil {
		return nil, err
	}
	return user, nil
}

// 引数の型のプレフィックスを小文字に変更
func (r *userRepository) UpdateUser(userRes domain.User) (string, error) {

	updates := []string{}
	params := []interface{}{}
	message := []string{}

	message = append(message, "ユーザーID'"+strconv.Itoa(userRes.UserID)+"'の")

	if userRes.Name != "" {
		updates = append(updates, "name = ?")
		params = append(params, userRes.Name)
		message = append(message, "名前を'"+userRes.Name+"'に、")
	}
	if userRes.Email != "" {
		updates = append(updates, "email = ?")
		params = append(params, userRes.Email)
		message = append(message, "Emailを'"+userRes.Email+"'に、")
	}
	if userRes.Password != "" {
		updates = append(updates, "password = ?")
		params = append(params, userRes.Password)
		message = append(message, "パスワードを'"+userRes.Password+"'に、")
	}

	message = append(message, "変更しました！")

	if len(updates) == 0 {
		return "ユーザーデータの更新は0件数です！", nil
	}

	query := "UPDATE Users SET " + strings.Join(updates, ", ") + " WHERE user_id = ?"
	params = append(params, userRes.UserID)

	_, err := r.db.Exec(query, params...)
	return strings.Join(message, ""), err
}

// 引数の型のプレフィックスを小文字に変更
func (repo *userRepository) GetUserDetails(userID string) (*domain.User, error) {
	query := `
        SELECT u.user_id, u.name, u.email, u.password,
               o.order_id, o.quantity, o.order_date,
               p.product_id, p.name, p.description, p.price
        FROM Users u
        LEFT JOIN Orders o ON u.user_id = o.user_id
        LEFT JOIN Products p ON o.product_id = p.product_id
        WHERE u.user_id = ?`

	rows, err := repo.db.Query(query, userID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var user domain.User
	var orders []domain.Order

	for rows.Next() {
		var order domain.Order
		var product domain.Product

		if err := rows.Scan(&user.UserID, &user.Name, &user.Email, &user.Password,
			&order.OrderID, &order.Quantity, &order.OrderDate,
			&product.ProductID, &product.Name, &product.Description, &product.Price); err != nil {
			return nil, err
		}

		order.Product = product
		orders = append(orders, order)
	}

	user.Orders = orders
	return &user, nil
}

mockgen -source=自分のプロジェクトまでの絶対パス\myApiProject\internal\repository\user_repository.go -destination=自分のプロジェクトまでの絶対パス\myApiProject\internal\repository\mock_user_repository.go -package=repository

// Code generated by MockGen. DO NOT EDIT.

// Package repository is a generated GoMock package.
package repository

import (
	domain "myApiProject/internal/domain"
	reflect "reflect"

	gomock "github.com/golang/mock/gomock"
)

// MockUserRepository is a mock of UserRepository interface.
type MockUserRepository struct {
	ctrl     *gomock.Controller
	recorder *MockUserRepositoryMockRecorder
}

// MockUserRepositoryMockRecorder is the mock recorder for MockUserRepository.
type MockUserRepositoryMockRecorder struct {
	mock *MockUserRepository
}

// NewMockUserRepository creates a new mock instance.
func NewMockUserRepository(ctrl *gomock.Controller) *MockUserRepository {
	mock := &MockUserRepository{ctrl: ctrl}
	mock.recorder = &MockUserRepositoryMockRecorder{mock}
	return mock
}

// EXPECT returns an object that allows the caller to indicate expected use.
func (m *MockUserRepository) EXPECT() *MockUserRepositoryMockRecorder {
	return m.recorder
}

// FindByID mocks base method.
func (m *MockUserRepository) FindByID(userID string) (*domain.User, error) {
	m.ctrl.T.Helper()
	ret := m.ctrl.Call(m, "FindByID", userID)
	ret0, _ := ret[0].(*domain.User)
	ret1, _ := ret[1].(error)
	return ret0, ret1
}

// FindByID indicates an expected call of FindByID.
func (mr *MockUserRepositoryMockRecorder) FindByID(userID interface{}) *gomock.Call {
	mr.mock.ctrl.T.Helper()
	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "FindByID", reflect.TypeOf((*MockUserRepository)(nil).FindByID), userID)
}

// GetUserDetails mocks base method.
func (m *MockUserRepository) GetUserDetails(userID string) (*domain.User, error) {
	m.ctrl.T.Helper()
	ret := m.ctrl.Call(m, "GetUserDetails", userID)
	ret0, _ := ret[0].(*domain.User)
	ret1, _ := ret[1].(error)
	return ret0, ret1
}

// GetUserDetails indicates an expected call of GetUserDetails.
func (mr *MockUserRepositoryMockRecorder) GetUserDetails(userID interface{}) *gomock.Call {
	mr.mock.ctrl.T.Helper()
	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "GetUserDetails", reflect.TypeOf((*MockUserRepository)(nil).GetUserDetails), userID)
}

// UpdateUser mocks base method.
func (m *MockUserRepository) UpdateUser(userRes domain.User) (string, error) {
	m.ctrl.T.Helper()
	ret := m.ctrl.Call(m, "UpdateUser", userRes)
	ret0, _ := ret[0].(string)
	ret1, _ := ret[1].(error)
	return ret0, ret1
}

// UpdateUser indicates an expected call of UpdateUser.
func (mr *MockUserRepositoryMockRecorder) UpdateUser(userRes interface{}) *gomock.Call {
	mr.mock.ctrl.T.Helper()
	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "UpdateUser", reflect.TypeOf((*MockUserRepository)(nil).UpdateUser), userRes)
}

// handlerパッケージのフォルダ構成
internal
┗//～いろんなパッケージ(省略)～
┗handler
　┗user_handler.go
　┗test
　　┗user_handler_test.go

package handler

import (
	"myApiProject/internal/domain"
	"myApiProject/internal/handler"
	"myApiProject/internal/repository"
	"myApiProject/internal/usecase"
	"net/http"
	"net/http/httptest"
	"testing"

	"github.com/golang/mock/gomock"
	"github.com/gorilla/mux"
	"github.com/stretchr/testify/assert"
)

func TestGetUser(t *testing.T) {
	// モックコントローラを作成
	ctrl := gomock.NewController(t)
	defer ctrl.Finish()

	// モックリポジトリを生成
	mockRepo := repository.NewMockUserRepository(ctrl)
	userUsecase := usecase.NewUserUseCase(mockRepo)
	userHandler := handler.NewUserHandler(userUsecase)

	// ルーターを設定
	r := mux.NewRouter()
	r.HandleFunc("/user", userHandler.GetUser).Methods("GET")

	// テストデータを作成
	testUser := &domain.User{
		UserID:   1,
		Name:     "山田太郎",
		Email:    "taro@example.com",
		Password: "password123",
	}

	// テスト用のHTTPリクエストを作成
	req, _ := http.NewRequest("GET", "/user?user_id=1", nil)
	rr := httptest.NewRecorder()

	// モックの期待値を設定
	mockRepo.EXPECT().FindByID("1").Return(testUser, nil)

	// リクエストを処理
	r.ServeHTTP(rr, req)

	// レスポンスのアサーション
	assert.Equal(t, http.StatusOK, rr.Code)
	assert.JSONEq(t, `{"user_id":1,"name":"山田太郎","email":"taro@example.com","password":"password123","orders":null}`, rr.Body.String())
}

	// モックコントローラを作成
	ctrl := gomock.NewController(t)
	defer ctrl.Finish()

	// モックリポジトリを生成
	mockRepo := repository.NewMockUserRepository(ctrl)
	userUsecase := usecase.NewUserUseCase(mockRepo)
	userHandler := handler.NewUserHandler(userUsecase)

	// ルーターを設定
	r := mux.NewRouter()
	r.HandleFunc("/user", userHandler.GetUser).Methods("GET")

	// テストデータを作成
	testUser := &domain.User{
		UserID:   1,
		Name:     "山田太郎",
		Email:    "taro@example.com",
		Password: "password123",
	}

	// テスト用のHTTPリクエストを作成
	req, _ := http.NewRequest("GET", "/user?user_id=1", nil)
	rr := httptest.NewRecorder()

	// モックの期待値を設定
	mockRepo.EXPECT().FindByID("1").Return(testUser, nil)

	// リクエストを処理
	r.ServeHTTP(rr, req)

	// レスポンスのアサーション
	assert.Equal(t, http.StatusOK, rr.Code)
	assert.JSONEq(t, `{"user_id":1,"name":"山田太郎","email":"taro@example.com","password":"password123","orders":null}`, rr.Body.String())