Generic get environment

generic_env.go

package utils

import (
	"os"
	"strconv"
)

type Env[T any] struct {
	DefaultVal T
	FromString func(string) (T, error)
}

var EnvString = Env[string]{
	DefaultVal: "",
	FromString: func(s string) (string, error) { return s, nil },
}
var EnvInt = Env[int]{
	DefaultVal: 0,
	FromString: strconv.Atoi,
}
var EnvBool = Env[bool]{
	DefaultVal: false,
	FromString: strconv.ParseBool,
}

// GetEnvT get env value of T type
func GetEnvT[T any](name string, e Env[T]) T {
	v := os.Getenv(name)

	if v == "" {
		return e.DefaultVal
	}

	d, err := e.FromString(v)
	if err != nil {
		return e.DefaultVal
	}

	return d
}