fix: wrap repr of bytes in double quotes

tests/formats/dataclass/serializers/test_code.py

@@ -104,10 +104,12 @@ def test_write_object_with_enum(self):
         iterator = self.serializer.write_object(Namespace.SOAP11, 0, set())
         self.assertEqual("Namespace.SOAP11", "".join(iterator))
 
-    def test_write_bytes_with_single_quote(self):
-        iterator = self.serializer.write_object(b"\xfaj'", 0, set())
-        self.assertEqual("b\"\\xfaj'\"", "".join(iterator))
+    def test_write_bytes(self):
+        iterator = self.serializer.write_object(b'a', 0, set())
+        self.assertEqual('b"a"', "".join(iterator))
 
+        iterator = self.serializer.write_object(b"\xfa\"'", 0, set())
+        self.assertEqual('b"\\xfa\"\\\'"', "".join(iterator))
 
     def test_build_imports_with_nested_types(self):
         expected = "from tests.fixtures.models import Parent\n"

xsdata/utils/objects.py

@@ -1,4 +1,5 @@
 import math
+import re
 from typing import Any
 from xml.etree.ElementTree import QName
 from xml.sax.saxutils import quoteattr
@@ -30,6 +31,7 @@ def literal_value(value: Any) -> str:
         return f'QName("{value.text}")'
 
     if isinstance(value, bytes):
-        return repr(value)
+        # Use the contents of the bytes verbatim, but ensure that it is wrapped in double quotes
+        return re.sub(r"b'(.*)'$", r'b"\g<1>"', repr(value))
 
     return repr(value).replace("'", '"')