Idiomatic way to validate structs

go, validation

Solution

I don't see any other way to do this quickly. But I found a go package which can help you with this: https://github.com/go-validator/validator

The README file gives this example:

type NewUserRequest struct {
    Username string `validator:"min=3,max=40,regexp=^[a-zA-Z]$"`
    Name string     `validator:"nonzero"`
    Age int         `validator:"min=21"`
    Password string `validator:"min=8"`
}

nur := NewUserRequest{Username: "something", Age: 20}
if valid, errs := validator.Validate(nur); !valid {
    // values not valid, deal with errors here
}

Problem

I need to validate that a struct value is correct and this means I need to check every field individually, which is easy for a small number of small structs but I was wondering if there's a better way to do it. Here's how I'm doing it right now. ``` type Event struct { Id int UserId int Start time.Time End time.Time Title string Notes string } func (e Event) IsValid() error { if e.Id <= 0 { return errors.New("Id must be greater than 0") } if e.UserId <= 0 { return errors.New("UserId must be greater than 0") } if e.End <= e.Start { return errors.New("End must be after Start") } if e.Start < time.Now() { return errors.New("Cannot create events in the past") } if e.Title == "" { return errors.New("Title cannot be empty") } return nil } ``` Is this the idiomatic way to validate the values of fields in a struct? It looks cumbersome.

Original source