neji

neji is a lightweight Go package for generating structured JSON error responses and handling parameter validation errors. It provides utility functions to standardize error handling in API applications.

Features

• 🔧 Structured JSON Error Responses: Generate consistent error responses in two formats
• ✅ Parameter Validation: Standardized missing parameter error messages
• 🔗 Error Wrapping: Preserve original errors while adding context
• 🧪 Well Tested: Comprehensive test coverage with edge cases
• 📦 Zero Dependencies: Only standard library (except for tests)

Installing

go get -u github.com/junkd0g/neji

✅ Running Tests

go test ./...

🚀 Usage

Basic Error Response

package main

import (
	"errors"
	"net/http"

	"github.com/gorilla/mux"
	nerror "github.com/junkd0g/neji"
)

func HelloWorld(w http.ResponseWriter, r *http.Request) {
	err := errors.New("This is the best error message ever")
	errorResponse, _ := nerror.SimpleErrorResponseWithStatus(500, err)

	w.Header().Set("Content-Type", "application/json")
	w.Write(errorResponse)
}

func main() {
	router := mux.NewRouter().StrictSlash(true)
	router.HandleFunc("/", HelloWorld)
	http.ListenAndServe(":8076", router)
}

API Reference

SimpleErrorResponseWithStatus

nerror.SimpleErrorResponseWithStatus(500, err)

Returns:

{
	"message": "Your json is wrong or something",
	"status": 500
}

SimpleErrorResponseWithCodeV2

nerror.SimpleErrorResponseWithCodeV2(500, err)

Returns:

{
	"error": {
		"status": 500,
		"message": "Your json is wrong or something"
	}
}

Parameter Validation

// Generate standardized parameter error
err := nerror.ErrInvalidParameter("user_id")
// Returns: "missing parameter user_id"

Error Wrapping

// Wrap errors with additional context
originalErr := errors.New("connection timeout")
wrappedErr := nerror.WrapError(originalErr, "failed to fetch data")
// Returns: "failed to fetch data: connection timeout"

📝 License

This project is licensed under the MIT License. See the LICENSE file for details.

Authors

• Iordanis Paschalidis -junkd0g