basic

Basic Error Definitions Example

This example demonstrates how to define basic error codes using YAML format.

errors.yaml

- code: 1001
  key: UserNotFound
  message: User not found
  http: 404
  grpc: 5
  desc: The specified user could not be found in the database

- code: 1002
  key: InvalidEmail
  message: Invalid email address
  http: 400
  grpc: 3
  desc: The provided email address is not valid

- code: 1003
  key: DatabaseError
  message: Database connection failed
  http: 500
  grpc: 13
  desc: Failed to connect to the database server

Generate Code

go run github.com/restayway/rescode/cmd/rescodegen --input errors.yaml --output errors_gen.go --package main

main.go

package main

import (
	"fmt"
	"log"
)

//go:generate go run github.com/restayway/rescode/cmd/rescodegen --input errors.yaml --output errors_gen.go --package main

func main() {
	// Create errors without wrapping
	userErr := UserNotFound()
	fmt.Printf("User error: %v\n", userErr)
	fmt.Printf("HTTP code: %d\n", userErr.HttpCode)
	fmt.Printf("gRPC code: %d\n", userErr.RpcCode)

	// Create error with wrapped error
	dbErr := fmt.Errorf("connection timeout")
	wrappedErr := DatabaseError(dbErr)
	fmt.Printf("Database error: %v\n", wrappedErr)
	fmt.Printf("Original error: %v\n", wrappedErr.OriginalError())

	// Add additional data
	emailErr := InvalidEmail().SetData(map[string]string{
		"email":    "invalid@",
		"field":    "email",
		"location": "signup form",
	})
	fmt.Printf("Email error JSON: %v\n", emailErr.JSON())

	// Use constants directly
	if userErr.Code == UserNotFoundCode {
		log.Printf("Handling user not found with code %d", UserNotFoundCode)
	}
}

Generated Code (errors_gen.go)

The command above will generate a file like this:

// Code generated by rescodegen. DO NOT EDIT.

package main

import (
	"github.com/restayway/rescode"
	"google.golang.org/grpc/codes"
)

// Error code constants
const (
	UserNotFoundCode uint64     = 1001
	UserNotFoundHTTP int        = 404
	UserNotFoundGRPC codes.Code = 5
	UserNotFoundMsg  string     = "User not found"
	UserNotFoundDesc string     = "The specified user could not be found in the database"

	InvalidEmailCode uint64     = 1002
	InvalidEmailHTTP int        = 400
	InvalidEmailGRPC codes.Code = 3
	InvalidEmailMsg  string     = "Invalid email address"
	InvalidEmailDesc string     = "The provided email address is not valid"

	DatabaseErrorCode uint64     = 1003
	DatabaseErrorHTTP int        = 500
	DatabaseErrorGRPC codes.Code = 13
	DatabaseErrorMsg  string     = "Database connection failed"
	DatabaseErrorDesc string     = "Failed to connect to the database server"
)

// UserNotFound creates a new UserNotFound error.
// The specified user could not be found in the database
func UserNotFound(err ...error) *rescode.RC {
	return rescode.New(UserNotFoundCode, UserNotFoundHTTP, UserNotFoundGRPC, UserNotFoundMsg)(err...)
}

// InvalidEmail creates a new InvalidEmail error.
// The provided email address is not valid
func InvalidEmail(err ...error) *rescode.RC {
	return rescode.New(InvalidEmailCode, InvalidEmailHTTP, InvalidEmailGRPC, InvalidEmailMsg)(err...)
}

// DatabaseError creates a new DatabaseError error.
// Failed to connect to the database server
func DatabaseError(err ...error) *rescode.RC {
	return rescode.New(DatabaseErrorCode, DatabaseErrorHTTP, DatabaseErrorGRPC, DatabaseErrorMsg)(err...)
}