Fail fast for required values

[x80486]

I'm integrating gookit/config in an existing project in order to manage the configuration. I've ran into some issues, but I've been able to workaround them in one way or another — I'm pretty new to Go as well 😬

What I've been able to do is to be able to interrupt the application bootstrapping when there is a missing value. For instance, consider the following configuration:

---
datasource:
  password: ${DATABASE_PASSWORD|unset}
  type: postgres
  username: ${DATABASE_USERNAME|postgres}
  url: ${DATABASE_URL|unset}

It would be great to have the behavior that Docker Compose provides to fail whenever a value for an environment variable is not present. Basically, if implemented exactly the same (bonus points!) the YAML file would be like this:

---
datasource:
  password: ${DATABASE_PASSWORD|?error}
  type: postgres
  username: ${DATABASE_USERNAME|postgres}
  url: ${DATABASE_URL|?error}

[inhere]

hi @x80486 I added support for required value checking. Next version release.
e.g: ${DATABASE_URL|?error}

[inhere]

hi @x80486 New version released