FINNOMENA ERROR

FINNOMENA Error is an extension of standard golang error which provides more flexibility to use with additional information about an error (Ex. stack tracing)

Prerequisites

Golang 1.13 or further version must be installed, in order to use the standard library functions such as errors.Is() or errors.As() to examine a child error in the error chain.

Installation

go get github.com/finnomena/go-fnerror

Example

package main

import (
	"errors"
	"fmt"

	"github.com/finnomena/go-fnerror"
)

func someFunction() fnerror.Apperror {
	return fnerror.NewUnexpectedError("CUSTOM MESSAGE", nil)
}

func main() {
	unexpectedErr := fnerror.NewUnexpectedError("", nil)
	notFoundErr := fnerror.NewNotFoundError("", unexpectedErr)
	fmt.Println(notFoundErr.Error())
	// Not Found
	fmt.Println(notFoundErr.GetCode())
	// 101 --> application error code
	fmt.Println(notFoundErr.GetHTTPCode())
	// 404 --> http response code
	fmt.Println(notFoundErr.GetTrace())
	// {$dir}/main.go:16
	fmt.Println(fnerror.GetChainTrace(notFoundErr))
	/*
		main.main() "Not Found"
		{$dir}/main.go:16

		main.main() "CUSTOM MESSAGE"
		{$dir}/main.go:15
	*/
	standardErr := errors.New("Error")
	unexpectedErr2 := new(fnerror.UnexpectedError) //allocate with new only for type assertion
	forbiddenErr := new(fnerror.ForbiddenError)

	fmt.Println(errors.Is(notFoundErr, standardErr))
	//false --> has no standard error (compare to a value)
	fmt.Println(errors.Is(notFoundErr, unexpectedErr))
	//true --> has unexpectedErr
	fmt.Println(errors.Is(notFoundErr, unexpectedErr2))
	//false --> doesn't has unexpectedErr2
	fmt.Println(errors.Is(notFoundErr, forbiddenErr))
	//false --> doesnt has forbiddenErr

	fmt.Println(errors.As(notFoundErr, &standardErr))
	//true --> contains error type (compare to a type)
	fmt.Println(errors.As(notFoundErr, &unexpectedErr2))
	//true --> contains UnexpectedError type
	fmt.Println(errors.As(notFoundErr, &forbiddenErr))
	//false --> contains ForbiddenError type
}

Contributing

• Use PR for a small change (including test case and doc)
• For a major change, open an issue for dicussion first.

License

MIT