refactor: The main function and some writes what I think is a better practice

app/main.go

@@ -7,18 +7,32 @@ import (
 	"net/url"
 	"time"
 
+	articleHttpDelivery "github.com/bxcodec/go-clean-arch/article/delivery/http"
+	httpMiddL "github.com/bxcodec/go-clean-arch/article/delivery/http/middleware"
+	articleRepo "github.com/bxcodec/go-clean-arch/article/repository/mysql"
+	articleUcase "github.com/bxcodec/go-clean-arch/article/usecase"
+	authorRepo "github.com/bxcodec/go-clean-arch/author/repository/mysql"
+	"github.com/bxcodec/go-clean-arch/domain"
+
 	_ "github.com/go-sql-driver/mysql"
 	"github.com/labstack/echo"
 	"github.com/spf13/viper"
-
-	_articleHttpDelivery "github.com/bxcodec/go-clean-arch/article/delivery/http"
-	_articleHttpDeliveryMiddleware "github.com/bxcodec/go-clean-arch/article/delivery/http/middleware"
-	_articleRepo "github.com/bxcodec/go-clean-arch/article/repository/mysql"
-	_articleUcase "github.com/bxcodec/go-clean-arch/article/usecase"
-	_authorRepo "github.com/bxcodec/go-clean-arch/author/repository/mysql"
 )
 
-func init() {
+func main() {
+	setupConfig()
+
+	articleUsecase := initRepositoriesAndUsecase()
+
+	e := echo.New()
+	e.Use(httpMiddL.CORS)
+
+	articleHttpDelivery.RegisterHandler(e, articleUsecase)
+
+	log.Fatal(e.Start(viper.GetString("server.address")))
+}
+
+func setupConfig() {
 	viper.SetConfigFile(`config.json`)
 	err := viper.ReadInConfig()
 	if err != nil {
@@ -30,7 +44,23 @@ func init() {
 	}
 }
 
-func main() {
+func initRepositoriesAndUsecase() domain.ArticleUsecase {
+	dbConn := initMySQL()
+	defer func() {
+		if err := dbConn.Close(); err != nil {
+			log.Fatal(err)
+		}
+	}()
+
+	authorRepo := authorRepo.NewMysqlAuthorRepository(dbConn)
+	ar := articleRepo.NewMysqlArticleRepository(dbConn)
+	timeoutContext := time.Duration(viper.GetInt("context.timeout")) * time.Second
+	au := articleUcase.NewArticleUsecase(ar, authorRepo, timeoutContext)
+
+	return au
+}
+
+func initMySQL() *sql.DB {
 	dbHost := viper.GetString(`database.host`)
 	dbPort := viper.GetString(`database.port`)
 	dbUser := viper.GetString(`database.user`)
@@ -41,32 +71,14 @@ func main() {
 	val.Add("parseTime", "1")
 	val.Add("loc", "Asia/Jakarta")
 	dsn := fmt.Sprintf("%s?%s", connection, val.Encode())
-	dbConn, err := sql.Open(`mysql`, dsn)
 
+	dbConn, err := sql.Open(`mysql`, dsn)
 	if err != nil {
 		log.Fatal(err)
 	}
-	err = dbConn.Ping()
-	if err != nil {
+
+	if err = dbConn.Ping(); err != nil {
 		log.Fatal(err)
 	}
-
-	defer func() {
-		err := dbConn.Close()
-		if err != nil {
-			log.Fatal(err)
-		}
-	}()
-
-	e := echo.New()
-	middL := _articleHttpDeliveryMiddleware.InitMiddleware()
-	e.Use(middL.CORS)
-	authorRepo := _authorRepo.NewMysqlAuthorRepository(dbConn)
-	ar := _articleRepo.NewMysqlArticleRepository(dbConn)
-
-	timeoutContext := time.Duration(viper.GetInt("context.timeout")) * time.Second
-	au := _articleUcase.NewArticleUsecase(ar, authorRepo, timeoutContext)
-	_articleHttpDelivery.NewArticleHandler(e, au)
-
-	log.Fatal(e.Start(viper.GetString("server.address")))
+	return dbConn
 }

article/delivery/http/article_handler.go

@@ -4,25 +4,25 @@ import (
 	"net/http"
 	"strconv"
 
+	"github.com/bxcodec/go-clean-arch/domain"
+
 	"github.com/labstack/echo"
 	"github.com/sirupsen/logrus"
-	validator "gopkg.in/go-playground/validator.v9"
-
-	"github.com/bxcodec/go-clean-arch/domain"
+	"gopkg.in/go-playground/validator.v9"
 )
 
-// ResponseError represent the reseponse error struct
+// ResponseError represent the response error struct
 type ResponseError struct {
 	Message string `json:"message"`
 }
 
-// ArticleHandler  represent the httphandler for article
+// ArticleHandler  represent the http handler for article
 type ArticleHandler struct {
 	AUsecase domain.ArticleUsecase
 }
 
-// NewArticleHandler will initialize the articles/ resources endpoint
-func NewArticleHandler(e *echo.Echo, us domain.ArticleUsecase) {
+// RegisterHandler will initialize the articles/ resources endpoint
+func RegisterHandler(e *echo.Echo, us domain.ArticleUsecase) {
 	handler := &ArticleHandler{
 		AUsecase: us,
 	}
@@ -33,13 +33,13 @@ func NewArticleHandler(e *echo.Echo, us domain.ArticleUsecase) {
 }
 
 // FetchArticle will fetch the article based on given params
-func (a *ArticleHandler) FetchArticle(c echo.Context) error {
+func (h *ArticleHandler) FetchArticle(c echo.Context) error {
 	numS := c.QueryParam("num")
 	num, _ := strconv.Atoi(numS)
 	cursor := c.QueryParam("cursor")
 	ctx := c.Request().Context()
 
-	listAr, nextCursor, err := a.AUsecase.Fetch(ctx, cursor, int64(num))
+	listAr, nextCursor, err := h.AUsecase.Fetch(ctx, cursor, int64(num))
 	if err != nil {
 		return c.JSON(getStatusCode(err), ResponseError{Message: err.Error()})
 	}
@@ -49,7 +49,7 @@ func (a *ArticleHandler) FetchArticle(c echo.Context) error {
 }
 
 // GetByID will get article by given id
-func (a *ArticleHandler) GetByID(c echo.Context) error {
+func (h *ArticleHandler) GetByID(c echo.Context) error {
 	idP, err := strconv.Atoi(c.Param("id"))
 	if err != nil {
 		return c.JSON(http.StatusNotFound, domain.ErrNotFound.Error())
@@ -58,7 +58,7 @@ func (a *ArticleHandler) GetByID(c echo.Context) error {
 	id := int64(idP)
 	ctx := c.Request().Context()
 
-	art, err := a.AUsecase.GetByID(ctx, id)
+	art, err := h.AUsecase.GetByID(ctx, id)
 	if err != nil {
 		return c.JSON(getStatusCode(err), ResponseError{Message: err.Error()})
 	}
@@ -76,7 +76,7 @@ func isRequestValid(m *domain.Article) (bool, error) {
 }
 
 // Store will store the article by given request body
-func (a *ArticleHandler) Store(c echo.Context) (err error) {
+func (h *ArticleHandler) Store(c echo.Context) (err error) {
 	var article domain.Article
 	err = c.Bind(&article)
 	if err != nil {
@@ -89,7 +89,7 @@ func (a *ArticleHandler) Store(c echo.Context) (err error) {
 	}
 
 	ctx := c.Request().Context()
-	err = a.AUsecase.Store(ctx, &article)
+	err = h.AUsecase.Store(ctx, &article)
 	if err != nil {
 		return c.JSON(getStatusCode(err), ResponseError{Message: err.Error()})
 	}
@@ -98,7 +98,7 @@ func (a *ArticleHandler) Store(c echo.Context) (err error) {
 }
 
 // Delete will delete article by given param
-func (a *ArticleHandler) Delete(c echo.Context) error {
+func (h *ArticleHandler) Delete(c echo.Context) error {
 	idP, err := strconv.Atoi(c.Param("id"))
 	if err != nil {
 		return c.JSON(http.StatusNotFound, domain.ErrNotFound.Error())
@@ -107,7 +107,7 @@ func (a *ArticleHandler) Delete(c echo.Context) error {
 	id := int64(idP)
 	ctx := c.Request().Context()
 
-	err = a.AUsecase.Delete(ctx, id)
+	err = h.AUsecase.Delete(ctx, id)
 	if err != nil {
 		return c.JSON(getStatusCode(err), ResponseError{Message: err.Error()})
 	}

article/delivery/http/middleware/middleware.go

@@ -2,20 +2,10 @@ package middleware
 
 import "github.com/labstack/echo"
 
-// GoMiddleware represent the data-struct for middleware
-type GoMiddleware struct {
-	// another stuff , may be needed by middleware
-}
-
 // CORS will handle the CORS middleware
-func (m *GoMiddleware) CORS(next echo.HandlerFunc) echo.HandlerFunc {
+func CORS(next echo.HandlerFunc) echo.HandlerFunc {
 	return func(c echo.Context) error {
 		c.Response().Header().Set("Access-Control-Allow-Origin", "*")
 		return next(c)
 	}
 }
-
-// InitMiddleware initialize the middleware
-func InitMiddleware() *GoMiddleware {
-	return &GoMiddleware{}
-}

article/repository/mysql/driver.go

@@ -0,0 +1,3 @@
+package mysql
+
+const DriverMySQL = "mysql"

article/repository/mysql/mysql_article.go

@@ -11,6 +11,8 @@ import (
 	"github.com/bxcodec/go-clean-arch/domain"
 )
 
+var _ domain.ArticleRepository = &mysqlArticleRepository{}
+
 type mysqlArticleRepository struct {
 	Conn *sql.DB
 }
@@ -20,46 +22,6 @@ func NewMysqlArticleRepository(Conn *sql.DB) domain.ArticleRepository {
 	return &mysqlArticleRepository{Conn}
 }
 
-func (m *mysqlArticleRepository) fetch(ctx context.Context, query string, args ...interface{}) (result []domain.Article, err error) {
-	rows, err := m.Conn.QueryContext(ctx, query, args...)
-	if err != nil {
-		logrus.Error(err)
-		return nil, err
-	}
-
-	defer func() {
-		errRow := rows.Close()
-		if errRow != nil {
-			logrus.Error(errRow)
-		}
-	}()
-
-	result = make([]domain.Article, 0)
-	for rows.Next() {
-		t := domain.Article{}
-		authorID := int64(0)
-		err = rows.Scan(
-			&t.ID,
-			&t.Title,
-			&t.Content,
-			&authorID,
-			&t.UpdatedAt,
-			&t.CreatedAt,
-		)
-
-		if err != nil {
-			logrus.Error(err)
-			return nil, err
-		}
-		t.Author = domain.Author{
-			ID: authorID,
-		}
-		result = append(result, t)
-	}
-
-	return result, nil
-}
-
 func (m *mysqlArticleRepository) Fetch(ctx context.Context, cursor string, num int64) (res []domain.Article, nextCursor string, err error) {
 	query := `SELECT id,title,content, author_id, updated_at, created_at
   						FROM article WHERE created_at > ? ORDER BY created_at LIMIT ? `
@@ -80,6 +42,7 @@ func (m *mysqlArticleRepository) Fetch(ctx context.Context, cursor string, num i
 
 	return
 }
+
 func (m *mysqlArticleRepository) GetByID(ctx context.Context, id int64) (res domain.Article, err error) {
 	query := `SELECT id,title,content, author_id, updated_at, created_at
   						FROM article WHERE ID = ?`
@@ -182,3 +145,43 @@ func (m *mysqlArticleRepository) Update(ctx context.Context, ar *domain.Article)
 
 	return
 }
+
+func (m *mysqlArticleRepository) fetch(ctx context.Context, query string, args ...interface{}) (result []domain.Article, err error) {
+	rows, err := m.Conn.QueryContext(ctx, query, args...)
+	if err != nil {
+		logrus.Error(err)
+		return nil, err
+	}
+
+	defer func() {
+		errRow := rows.Close()
+		if errRow != nil {
+			logrus.Error(errRow)
+		}
+	}()
+
+	result = make([]domain.Article, 0)
+	for rows.Next() {
+		t := domain.Article{}
+		authorID := int64(0)
+		err = rows.Scan(
+			&t.ID,
+			&t.Title,
+			&t.Content,
+			&authorID,
+			&t.UpdatedAt,
+			&t.CreatedAt,
+		)
+
+		if err != nil {
+			logrus.Error(err)
+			return nil, err
+		}
+		t.Author = domain.Author{
+			ID: authorID,
+		}
+		result = append(result, t)
+	}
+
+	return result, nil
+}

article/usecase/article_ucase.go

@@ -4,10 +4,10 @@ import (
 	"context"
 	"time"
 
+	"github.com/bxcodec/go-clean-arch/domain"
+
 	"github.com/sirupsen/logrus"
 	"golang.org/x/sync/errgroup"
-
-	"github.com/bxcodec/go-clean-arch/domain"
 )
 
 type articleUsecase struct {

author/repository/mysql/driver.go

@@ -0,0 +1,3 @@
+package mysql
+
+const DriverMySQL = "mysql"