♻️ Use uint8 for Env

cmd/combluotion/main.go

@@ -49,6 +49,7 @@ func getTomlFile() string {
 
 var confStr = `
 base_url = "http://localhost:4523/"
+env = "dev"
 
 [stores]
 store = "sqlite"

config/config_test.go

@@ -13,7 +13,7 @@ func TestEnvDefaultsToDev(t *testing.T) {
 }
 
 func TestInvalidEnvReturnsDev(t *testing.T) {
-	c := config{env: Env("foobar")}
+	c := config{env: Env(255)}
 	assert.Equal(t, Dev, c.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)
-}

config/env_string.go

@@ -0,0 +1,27 @@
+// Code generated by "stringer -type Env"; DO NOT EDIT.
+
+package config
+
+import "strconv"
+
+func _() {
+	// An "invalid array index" compiler error signifies that the constant values have changed.
+	// Re-run the stringer command to generate them again.
+	var x [1]struct{}
+	_ = x[Dev-1]
+	_ = x[Prod-2]
+	_ = x[Qa-3]
+	_ = x[Test-4]
+}
+
+const _Env_name = "DevProdQaTest"
+
+var _Env_index = [...]uint8{0, 3, 7, 9, 13}
+
+func (i Env) String() string {
+	i -= 1
+	if i >= Env(len(_Env_index)-1) {
+		return "Env(" + strconv.FormatInt(int64(i+1), 10) + ")"
+	}
+	return _Env_name[_Env_index[i]:_Env_index[i+1]]
+}

config/env_test.go

@@ -1,21 +1,81 @@
 package config
 
 import (
+	"encoding"
+	"fmt"
+	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
 )
 
+var _ encoding.TextMarshaler = Env(0)
+var _ encoding.TextUnmarshaler = new(Env)
+var _ fmt.Stringer = Env(0)
+
 func TestEnvString(t *testing.T) {
-	cases := Envs[:]
-	cases = append(cases, Env("foobar"), Env(""), Env("42"), Env("✨"))
-	for _, e := range cases {
-		t.Run(string(e), func(t *testing.T) {
-			assert.Equal(t, string(e), e.String())
+	testcases := []struct {
+		expected string
+		val      Env
+	}{
+		{"Dev", Dev},
+		{"Prod", Prod},
+		{"Qa", Qa},
+		{"Test", Test},
+		{"Env(0)", Env(0)},
+		{"Env(255)", Env(255)},
+	}
+	for _, testcase := range testcases {
+		t.Run(testcase.expected, func(sub *testing.T) {
+			assert.Equal(t, testcase.expected, testcase.val.String())
+			by, er := testcase.val.MarshalText()
+			assert.NoError(t, er)
+			assert.Equal(t, []byte(testcase.expected), by)
 		})
 	}
 }
 
+type unmarshaltest struct {
+	name string
+	in   []byte
+	exp  Env
+	err  string
+}
+
+func TestEnvUnmarshalText(t *testing.T) {
+	testcases := []unmarshaltest{
+		{"empty", []byte{}, Env(0), "invalid value: "},
+		{"bad value", []byte("foobar"), Env(0), "invalid value: foobar"},
+	}
+	for _, e := range Envs {
+		testcases = append(testcases, unmarshaltest{e.String() + "-lower", []byte(strings.ToLower(e.String())), e, ""})
+		testcases = append(testcases, unmarshaltest{e.String() + "-upper", []byte(strings.ToUpper(e.String())), e, ""})
+		testcases = append(testcases, unmarshaltest{e.String(), []byte(e.String()), e, ""})
+	}
+
+	for _, testcase := range testcases {
+		t.Run(testcase.name, func(sub *testing.T) {
+			var e Env
+			er := (&e).UnmarshalText(testcase.in)
+			if testcase.err == "" {
+				assert.NoError(t, er)
+				assert.Equal(t, testcase.exp, e)
+			} else {
+				assert.Empty(t, e)
+				assert.ErrorContains(t, er, testcase.err)
+				assert.ErrorIs(t, er, ErrEnvUnmarshal)
+			}
+		})
+	}
+}
+
+func TestEnvUnmarshalTextNil(t *testing.T) {
+	var e *Env
+	er := e.UnmarshalText([]byte("prod"))
+	assert.ErrorContains(t, er, "nil pointer")
+	assert.ErrorIs(t, er, ErrEnvUnmarshal)
+}
+
 func TestValidEnv(t *testing.T) {
 	cases := [...]struct {
 		e   Env
@@ -25,9 +85,8 @@ func TestValidEnv(t *testing.T) {
 		{Prod, true},
 		{Qa, true},
 		{Test, true},
-		{Env("foobar"), false},
-		{Env(""), false},
-		{Env("✨"), false},
+		{Env(0), false},
+		{Env(255), false},
 	}
 
 	for _, c := range cases {
@@ -46,9 +105,8 @@ func TestValidEnvOrDev(t *testing.T) {
 		{Prod, Prod},
 		{Qa, Qa},
 		{Test, Test},
-		{Env("foobar"), Dev},
-		{Env(""), Dev},
-		{Env("✨"), Dev},
+		{Env(0), Dev},
+		{Env(255), Dev},
 	}
 
 	for _, c := range cases {

config/load_test.go

@@ -23,6 +23,7 @@ func TestLoadTomlGood(t *testing.T) {
 	defer os.Remove(tmp.Name())
 	defer tmp.Close()
 	fmt.Fprintln(tmp, `name = "Cool"`)
+	fmt.Fprintln(tmp, `env = "prod"`)
 	fmt.Fprintln(tmp, "[stores]")
 	fmt.Fprintln(tmp, `store = "sqlite"`)
 	fmt.Fprintln(tmp, "[stores.settings.sqlite]")
@@ -31,6 +32,7 @@ func TestLoadTomlGood(t *testing.T) {
 	c, e := LoadFromToml(tmp.Name())
 	assert.NoError(t, e)
 	assert.Equal(t, "Cool", c.Name())
+	assert.Equal(t, Prod, c.Env())
 
 	st, err := c.Store("")
 	assert.NoError(t, err)