fix: no need for idna conversion in domain validator

internal/utils/app_utils.go

@@ -38,7 +38,16 @@ func SafeParseAppURL(str string) (string, error) {
 		return "", fmt.Errorf("ip addresses not allowed")
 	}
 
-	hostname, err = idna.Lookup.ToASCII(hostname)
+	i := idna.New(
+		idna.MapForLookup(),
+		idna.Transitional(false),
+		idna.BidiRule(),
+		idna.StrictDomainName(false),
+		idna.CheckHyphens(true),
+		idna.CheckJoiners(false),
+	)
+
+	hostname, err = i.ToASCII(hostname)
 
 	if err != nil {
 		return "", fmt.Errorf("failed to convert hostname to ascii: %w", err)

internal/utils/app_utils_test.go

@@ -43,6 +43,13 @@ func TestSafeParseAPPURL(t *testing.T) {
 	assert.NoError(t, err)
 	assert.Equal(t, expected, result)
 
+	// Underscores
+	appURL = "http://sub_tinyauth.app"
+	expected = "http://sub_tinyauth.app"
+	result, err = utils.SafeParseAppURL(appURL)
+	assert.NoError(t, err)
+	assert.Equal(t, expected, result)
+
 	// Lowercase
 	appURL = "HTTP://SUb.tinyAUth.aPP"
 	expected = "http://sub.tinyauth.app"
@@ -66,7 +73,7 @@ func TestSafeParseAPPURL(t *testing.T) {
 	assert.ErrorContains(t, err, "invalid url")
 
 	// Invalid punycode
-	appURL = "http://ab--cd.example.com"
+	appURL = "http://xn--h-kva.example.com"
 	_, err = utils.SafeParseAppURL(appURL)
 	assert.ErrorContains(t, err, "failed to convert hostname to ascii")
 

pkg/validators/domain_validator.go

@@ -11,8 +11,6 @@ import (
 	"net"
 	"net/url"
 	"strings"
-
-	"golang.org/x/net/idna"
 )
 
 // Errors
@@ -114,23 +112,11 @@ func (v *DomainValidator) getURL(i string) (*url.URL, error) {
 }
 
 func (v *DomainValidator) getHostname(hostname string) (string, error) {
-	hostname = strings.ToLower(hostname)
-	hostname = strings.TrimSuffix(hostname, ".")
 	if net.ParseIP(hostname) != nil {
 		return "", fmt.Errorf("ip addresses are not supported")
 	}
-	i := idna.New(
-		idna.MapForLookup(),
-		idna.Transitional(false),
-		idna.BidiRule(),
-		idna.StrictDomainName(false),
-		idna.CheckHyphens(false),
-		idna.CheckJoiners(false),
-	)
-	hostname, err := i.ToASCII(hostname)
-	if err != nil {
-		return "", fmt.Errorf("failed to convert hostname to ascii: %w", err)
-	}
+	hostname = strings.ToLower(hostname)
+	hostname = strings.TrimSuffix(hostname, ".")
 	return hostname, nil
 }
 

pkg/validators/domain_validator_test.go

@@ -50,16 +50,6 @@ func TestDomainValidator_SafeHostname(t *testing.T) {
 			input:       "https://example.com",
 			expected:    "example.com",
 		},
-		{
-			description: "Domain with underscores should pass",
-			input:       "https://my_domain.com",
-			expected:    "my_domain.com",
-		},
-		{
-			description: "Domain with leading hyphen should pass",
-			input:       "https://-my-domain.com",
-			expected:    "-my-domain.com",
-		},
 		{
 			description: "Domain without scheme should parse if scheme is disabled",
 			input:       "example.com",
@@ -111,18 +101,6 @@ func TestDomainValidator_SafeHostname(t *testing.T) {
 				assert.ErrorContains(t, e, "ip addresses are not supported")
 			},
 		},
-		{
-			description: "Domains with unicode characters should be allowed",
-			input:       "bücher.example.com",
-			expected:    "xn--bcher-kva.example.com",
-		},
-		{
-			description: "Invalid IDNA domain should fail",
-			input:       "xn--r-kva.example.com",
-			errorFunc: func(t *testing.T, e error) {
-				assert.ErrorContains(t, e, "invalid label")
-			},
-		},
 		{
 			description: "With port enabled without any port should work",
 			options:     DomainValidatorOptions{WithPort: true},
@@ -204,22 +182,6 @@ func TestDomainValidator_Validate(t *testing.T) {
 			expected:    "https://example.com:443",
 			actual:      "https://example.com:443",
 		},
-		{
-			description: "Failure to format expected domain should fail",
-			expected:    "xn--r-kva.example.com",
-			actual:      "example.com",
-			errorFunc: func(t *testing.T, e error) {
-				assert.ErrorContains(t, e, "idna: invalid label")
-			},
-		},
-		{
-			description: "Failure to format check domain should fail",
-			expected:    "example.com",
-			actual:      "xn--r-kva.example.com",
-			errorFunc: func(t *testing.T, e error) {
-				assert.ErrorContains(t, e, "idna: invalid label")
-			},
-		},
 		{
 			description: "Valid domains with matching schemes and ports should pass",
 			options:     DomainValidatorOptions{WithScheme: true, AllowedSchemes: []string{"https", "http"}, WithPort: true},
@@ -246,16 +208,6 @@ func TestDomainValidator_Validate(t *testing.T) {
 			actual:      "example.com",
 			expected:    "example.com",
 		},
-		{
-			description: "Unicode valid domains should pass",
-			expected:    "xn--bcher-kva.example.com",
-			actual:      "bücher.example.com",
-		},
-		{
-			description: "Unicode valid domains should pass (reverse)",
-			expected:    "bücher.example.com",
-			actual:      "xn--bcher-kva.example.com",
-		},
 		{
 			description: "Non matching hostnames should fail",
 			expected:    "example.com",