Handle named errors with switch-case

named-errors-in-golang.go

// BaseError ...
type BaseError struct {
	s string
}

func (e *BaseError) Error() string {
	return e.s
}

// SomeError ...
type SomeError struct {
	BaseError
}

// OtherError ...
type OtherError struct {
	BaseError
}

func main() {
	err := &SomeError{BaseError{"some error"}}
	switch err := err.(type) {
	case *SomeError:
		//...
	case *OtherError:
		//...
	}
}