Better unicode conversion

gemini/processing.go

@@ -10,25 +10,25 @@ import (
 	"golang.org/x/text/transform"
 )
 
-func EnsureValidUTF8(input []byte) (string, error) {
+func BytesToValidUTF8(input []byte) (string, error) {
-	// Remove NULL byte 0x00
+	// Remove NULL byte 0x00 (ReplaceAll accepts slices)
-	inputNoNull := bytes.ReplaceAll(input, []byte{0}, nil)
+	inputNoNull := bytes.ReplaceAll(input, []byte{byte(0)}, []byte{})
 	isValidUTF8 := utf8.Valid(inputNoNull)
-	if !isValidUTF8 {
+	if isValidUTF8 {
+		return string(inputNoNull), nil
+	}
 	encodings := []transform.Transformer{
 		charmap.ISO8859_1.NewDecoder(),   // First try ISO8859-1
 		charmap.Windows1252.NewDecoder(), // Then try Windows-1252, etc
 		// TODO: Try more encodings?
 	}
-		// First successful conversion wins
+	// First successful conversion wins.
 	for _, encoding := range encodings {
 		reader := transform.NewReader(bytes.NewReader(inputNoNull), encoding)
 		result, err := io.ReadAll(reader)
-			if err != nil {
+		if err == nil {
-				return "", fmt.Errorf("UTF-8 error: %w", err)
-			}
 			return string(result), nil
 		}
 	}
-	return string(inputNoNull), nil
+	return "", fmt.Errorf("UTF-8 error: %w", err)
 }

gemini/processing_test.go

@@ -6,7 +6,7 @@ import "testing"
 func TestEnsureValidUTF8(t *testing.T) {
 	// Create a string with a null byte
 	strWithNull := "Hello" + string('\x00') + "world"
-	result, _ := EnsureValidUTF8([]byte(strWithNull))
+	result, _ := BytesToValidUTF8([]byte(strWithNull))
 	if result != "Helloworld" {
 		t.Errorf("Expected string without NULL byte, got %s", result)
 	}