Package: the importance of naming files when using initialization - go

Question

I wrote a structure like display in the tree below.
.
├── README.md
├── db
│ └── db.go
├── go.mod
├── go.sum
├── handler
│ ├── category.go
│ ├── handler.go
│ └── users.go
├── main.go
├── model
│ ├── category.go
│ ├── model.go
│ └── users.go
└── route
├── category.go // init() ❌ error to using package vars
├── route.go // init() writing package vars
└── users.go // init() ✅ no error to using package vars
All the files in the packages except the one with the same name (route/route.go, handler/handler.go,...) are generated automatically. For these files to extend the package variables, I use golang's func init(){} ex:
route/route.go
package route
import (
"github.com/labstack/echo/v4"
"github.com/labstack/echo/v4/middleware"
)
var (
// public routes
e *echo.Echo = echo.New()
// restricted routes
r *echo.Group = e.Group("/restricted")
)
func init() {
e.Use(middleware.CORSWithConfig(middleware.CORSConfig{
AllowOrigins: []string{"http://localhost:3000"},
AllowMethods: []string{echo.GET, echo.PUT, echo.POST, echo.DELETE, echo.OPTIONS},
AllowHeaders: []string{echo.HeaderAuthorization, echo.HeaderContentType},
}))
e.Use(middleware.Recover())
r.Use(middleware.JWT([]byte("secret")))
}
route/category.go
package route
import (
"github.com/username/project/handler"
)
func init() {
r.GET("/category", handler.ListCategory)
r.POST("/category/add", handler.CreateCategory)
r.GET("/category/:id", handler.ReadCategory)
r.PUT("/category/edit/:id", handler.UpdateCategory)
r.DELETE("/category/:id", handler.DeleteCategory)
}
route/user.go
package route
import (
"github.com/username/project/handler"
)
func init() {
r.GET("/users", handler.ListUsers)
r.POST("/users/add", handler.CreateUser)
r.PUT("/users/edit/:id", handler.UpdateUser)
r.DELETE("/users/:id", handler.DeleteUser)
e.POST("/auth", handler.Login)
e.POST("/lost", handler.Lost)
e.POST("/password", handler.Password)
}
As you already understood, the category.go init() starts before the router.go init(), which is described here: Go Package initialization.
After coding a pretty program that auto writes routes like route/category.go. I realize that to solve this problem, I will have to rename router/router.go to router/0router.go (it works) so that it is still at the top of the pillar, but it's not a good approach.
Have any suggestions for this tree and the use of golang ini() ?
Thank you

Answer 1

Use variable declaration expressions to avoid file name dependencies. The assignments execute before the init() functions that reference the variables.
var (
// public routes
e *echo.Echo = newPublic()
// restricted routes
r *echo.Group = newRestricted()
)
func newPublic() *echo.Echo {
e := echo.New()
e.Use(middleware.CORSWithConfig(middleware.CORSConfig{
AllowOrigins: []string{"http://localhost:3000"},
AllowMethods: []string{echo.GET, echo.PUT, echo.POST, echo.DELETE, echo.OPTIONS},
AllowHeaders: []string{echo.HeaderAuthorization, echo.HeaderContentType},
}))
e.Use(middleware.Recover())
}
func newRestricted() *echo.Group {
r := e.Group("/restricted")
r.Use(middleware.JWT([]byte("secret")))
return r
}