WIP Validation for env variables

bootstrap/app/conf/conf.go

@@ -1,3 +1,17 @@
 package conf
 
+import (
+	v "github.com/anthdm/superkit/validate"
+)
+
 // Application config
+
+var Env = struct {
+	SUPERKIT_ENV     string
+	HTTP_LISTEN_ADDR string
+	SUPERKIT_SECRET  string
+}{
+	SUPERKIT_ENV:     v.Env[string]("SUPERKIT_ENV", v.Rules(v.In([]string{"development", "staging", "production"})), "development"),
+	HTTP_LISTEN_ADDR: v.Env[string]("HTTP_LISTEN_ADDR", v.Rules(v.Min(3)), ":3000"),
+	SUPERKIT_SECRET:  v.Env[string]("SUPERKIT_SECRET", v.Required, v.Rules(v.Min(32))),
+}

bootstrap/cmd/app/main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"AABBCCDD/app"
+	"AABBCCDD/app/conf"
 	"AABBCCDD/public"
 	"fmt"
 	"log"
@@ -34,7 +35,7 @@ func main() {
 	app.InitializeRoutes(router)
 	app.RegisterEvents()
 
-	listenAddr := os.Getenv("HTTP_LISTEN_ADDR")
+	listenAddr := conf.Env.HTTP_LISTEN_ADDR
 	// In development link the full Templ proxy url.
 	url := "http://localhost:7331"
 	if kit.IsProduction() {

go.sum

@@ -0,0 +1,20 @@
+github.com/a-h/templ v0.2.707 h1:T1Gkd2ugbRglZ9rYw/VBchWOSZVKmetDbBkm4YubM7U=
+github.com/a-h/templ v0.2.707/go.mod h1:5cqsugkq9IerRNucNsI4DEamdHPsoGMQy99DzydLhM8=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
+github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
+github.com/google/gofuzz v1.2.0 h1:xRy4A+RhZaiKjJ1bPfwQ8sedCA+YS2YcCHW6ec7JMi0=
+github.com/google/gofuzz v1.2.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
+github.com/gorilla/securecookie v1.1.2 h1:YCIWL56dvtr73r6715mJs5ZvhtnY73hBvEF8kXD8ePA=
+github.com/gorilla/securecookie v1.1.2/go.mod h1:NfCASbcHqRSY+3a8tlWJwsQap2VX5pwzwo4h3eOamfo=
+github.com/gorilla/sessions v1.3.0 h1:XYlkq7KcpOB2ZhHBPv5WpjMIxrQosiZanfoy1HLZFzg=
+github.com/gorilla/sessions v1.3.0/go.mod h1:ePLdVu+jbEgHH+KWw8I1z2wqd0BAdAQh/8LRvBeoNcQ=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
+github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

validate/env.go

@@ -0,0 +1,90 @@
+package validate
+
+import (
+	"fmt"
+	"os"
+	"reflect"
+	"strconv"
+)
+
+type SupportedEnvTypes interface {
+	~int | ~float64 | ~bool | ~string
+}
+
+func coerceString[T SupportedEnvTypes](val string) (T, error) {
+	var result T
+
+	switch any(result).(type) {
+	case int:
+		var tmp int
+		tmp, err := strconv.Atoi(val)
+		if err != nil {
+			return result, err
+		}
+
+		result = any(tmp).(T)
+	case float64:
+		tmp, err := strconv.ParseFloat(val, 64)
+		if err != nil {
+			return result, err
+		}
+		result = any(tmp).(T)
+
+	case bool:
+		tmp, err := strconv.ParseBool(val)
+		if err != nil {
+			return result, err
+		}
+		result = any(tmp).(T)
+	case string:
+		result = any(val).(T)
+	default:
+		return result, fmt.Errorf("unsupported type: %T", result)
+	}
+
+	return result, nil
+}
+
+func isZeroValue(x any) bool {
+	if x == nil {
+		return true
+	}
+
+	v := reflect.ValueOf(x)
+	if !v.IsValid() {
+		return true
+	}
+
+	// Check if the value is the zero value for its type
+	zeroValue := reflect.Zero(v.Type())
+	return reflect.DeepEqual(v.Interface(), zeroValue.Interface())
+}
+
+func Env[T SupportedEnvTypes](key string, rulesSets []RuleSet, defaultValue ...T) T {
+
+	str := os.Getenv(key)
+
+	val, err := coerceString[T](str)
+
+	if err != nil || isZeroValue(val) {
+		if len(defaultValue) > 0 {
+			return defaultValue[0]
+		} else {
+			panic(fmt.Errorf("failed to parse env %s: %v", key, err))
+		}
+	}
+
+	fieldName := key
+	fieldValue := val
+
+	for _, set := range rulesSets {
+		set.FieldValue = fieldValue
+		set.FieldName = fieldName
+		if !set.ValidateFunc(set) {
+			msg := set.MessageFunc(set)
+			panic(fmt.Sprintf("Error parsing env %s: %s", key, msg))
+		}
+	}
+
+	return val
+}

validate/env_test.go

@@ -0,0 +1,59 @@
+package validate
+
+import (
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestEmptyEnv(t *testing.T) {
+	assert.Panics(t, func() {
+		_ = Env[string]("TEST", Rules(Required))
+	})
+
+	assert.Panics(t, func() {
+		os.Setenv("TEST", "")
+		_ = Env[string]("TEST", Rules(Required))
+	})
+}
+
+func TestReturnsValue(t *testing.T) {
+
+	os.Setenv("TEST", "value")
+
+	val := Env[string]("TEST", Rules(Required))
+	assert.Equal(t, val, "value")
+}
+
+func TestDefault(t *testing.T) {
+	val := Env[string]("TEST2", Rules(Required), "hello")
+	assert.Equal(t, "hello", val)
+
+	os.Setenv("TEST2", "world")
+	val = Env[string]("TEST2", Rules(Required), "hello")
+	assert.Equal(t, "world", val)
+
+	assert.Panics(t, func() {
+		os.Setenv("TEST2", "1")
+		_ = Env[string]("TEST2", Rules(Min(4)))
+	})
+}
+
+func TestInt(t *testing.T) {
+	os.Setenv("TEST", "1")
+	val := Env[int]("TEST", Rules(LT(2)))
+	assert.Equal(t, 1, val)
+}
+
+func TestBool(t *testing.T) {
+	os.Setenv("TEST", "true")
+	val := Env[bool]("TEST", Rules(EQ(true)))
+	assert.Equal(t, true, val)
+}
+
+func TestFloat(t *testing.T) {
+	os.Setenv("TEST", "1.1")
+	val := Env[float64]("TEST", Rules(GT(1.0)))
+	assert.Equal(t, 1.1, val)
+}