♻️ Use uint8 for Env

config/env.go

@@ -1,12 +1,20 @@
 package config
 
-type Env string
+import (
+	"errors"
+	"fmt"
+	"strings"
+)
+
+//go:generate stringer -type Env
+
+type Env uint8
 
 const (
-	Dev  Env = "dev"
-	Prod Env = "prod"
-	Qa   Env = "qa"
-	Test Env = "test"
+	Dev Env = iota + 1
+	Prod
+	Qa
+	Test
 )
 
 var Envs = [...]Env{
@@ -16,6 +24,28 @@ var Envs = [...]Env{
 	Test,
 }
 
+func (e Env) MarshalText() ([]byte, error) {
+	return []byte(e.String()), nil
+}
+
+var ErrEnvUnmarshal = errors.New("unable to unmarshal value")
+
+func (e *Env) UnmarshalText(text []byte) error {
+	if e == nil {
+		return fmt.Errorf("%w: nil pointer", ErrEnvUnmarshal)
+	}
+
+	val := strings.ToUpper(string(text))
+
+	for _, ee := range Envs {
+		if val == strings.ToUpper(ee.String()) {
+			*e = ee
+			return nil
+		}
+	}
+	return fmt.Errorf("%w: invalid value: %s", ErrEnvUnmarshal, text)
+}
+
 func ValidEnvOrDev(e Env) Env {
 	if ValidEnv(e) {
 		return e
@@ -31,7 +61,3 @@ func ValidEnv(env Env) bool {
 	}
 	return false
 }
-
-func (e Env) String() string {
-	return string(e)
-}