This library wraps errors from golang's json package and famous go-playground/validator library. The idea is to provide error message that is more friendly for consumer of your json APIs.
For instance, instead of json: cannot unmarshal string into Go struct field birthday.birthday.month of type int8 (error message from json pkg)
this library says 'birthday.month' should be integer but received string.
Note for go-playground/validator one can just use translation: eg https://github.com/go-playground/validator/blob/master/_examples/translations/main.go
Simply wrap error from json package or validator library
err := json.Unmarshal([]byte(input), &struct)
errmsg.Message(err)
err := validate.Struct(r)
errmsg.Message(err)