responsable-errors/interface.go

package errors

import "encoding/json"

// ResponsableError is an error that has information useful in an HTTP response.
// The string returned by Error should be suitable for logging useful information
// to assist debugging the error.
//
// Status should return an appropriate HTTP status. It must not return < 100 || >= 600.
//
// Msg should return a message suitable to display to the end user. If the message
// returned by Error is safe for the end user, it may simply call that.
//
// JSON should return something that can be marshalled to JSON for the response body.
// It can be something as simple as map[string]string{"error":err.Msg()}.
// JSON's return value should be used by MarshalJSON()
type ResponsableError interface {
	json.Marshaler
	Error() string
	Status() int
	Msg() string
	JSON() any
}

// SettableError is a ResponsableError which can be modified after initial creation.
//
// The SetStatus method can set the status, while the SetMsg method can set user message.
// If any values are passed after the message, it should be passed to fmt.Sprintf for formatting.
//
// Methods are chainable.
//
// SetStatus should not use a value outside of 100-599. It may either ignore such values, or panic.
//
// SetField should add some metadata to the error, which will be included in the data returned by JSON()
type SettableError interface {
	ResponsableError
	SetStatus(int) SettableError
	SetMsg(string, ...any) SettableError
	SetField(string, any) SettableError
}

// UnwrappableError allows a ResponsableError to wrap another error.
// It may be appropriate for Error() to delegate to the wrapped error.
type UnwrappableError interface {
	ResponsableError
	Unwrap() error
}

// UnwrappableErrorrs allows a ResponsableError to wrap multiple errors.
// It may be appropriate for Error() to either delegate to the first error,
// the last error, or to concatenate the return values of all wrapped errors,
// similar to errors returned by errors.Join
type UnwrappableErrors interface {
	ResponsableError
	Unwrap() []error
}

type wrappedError interface {
	Error() string
	Unwrap() error
}

type wrappedErrors interface {
	Error() string
	Unwrap() []error
}