Advanced Guide

Error Handling

GoFr provides a structured error handling approach to simplify error management in your applications. The errors package in GoFr provides functionality for handling errors in GoFr applications. It includes predefined HTTP and database errors, as well as the ability to create custom errors with additional context.

Pre-defined HTTP Errors

GoFr’s http package offers several predefined error types to represent common HTTP error scenarios. These errors automatically handle HTTP status code selection. These include:

  • ErrorInvalidParam: Represents an error due to an invalid parameter.
  • ErrorMissingParam: Represents an error due to a missing parameter.
  • ErrorEntityNotFound: Represents an error due to a not found entity.

Usage:

To use the predefined http errors,users can simply call them using GoFr's http package:

 err := http.ErrorMissingParam{Param: []string{"id"}}

Database Errors

Database errors in GoFr, represented in the datasource package, encapsulate errors related to database operations such as database connection, query failure, availability etc. The ErrorDB struct can be used to populate error as well as any custom message to it.

Usage:

// Creating a custom error wrapped in  underlying error for database operations
dbErr := datasource.ErrorDB{Err: err, Message: "error from sql db"}

// Adding stack trace to the error
dbErr = dbErr.WithStack()

// Creating a custom error only with error message and no underlying error.
dbErr2 := datasource.ErrorDB{Message : "database connection timed out!"}

Custom Errors

GoFr's error structs implements an interface with Error() string and StatusCode() int methods, users can override the status code by implementing it for their custom error.

Usage:

type customError struct {
	error string
}

func (c customError) Error() string {
	return fmt.Sprintf("custom error: %s", c.error)
}

func (c customError) StatusCode() int {
	return http.StatusMethodNotAllowed
}