diff --git a/__pycache__/main.cpython-313.pyc b/__pycache__/main.cpython-313.pyc
new file mode 100644
index 0000000..5ac6c39
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diff --git a/__pycache__/test_manage_schema.cpython-313.pyc b/__pycache__/test_manage_schema.cpython-313.pyc
new file mode 100644
index 0000000..5cace6d
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diff --git a/main.py b/main.py
index 5a09454..e284fcc 100755
--- a/main.py
+++ b/main.py
@@ -26,6 +26,10 @@ def normalize(def_str: bytes) -> bytes:
     """
     return re.sub(rb'\s+', b' ', def_str.strip())
 
+def extract_oid(ldif: str) -> str:
+    match = re.search(r'\(\s*([\d\.]+)', ldif)
+    return match.group(1) if match else ''
+
 def main():
     parser = argparse.ArgumentParser(
         description='Create or update OpenLDAP schema entries under cn=config'
@@ -162,11 +166,6 @@ def main():
 
             norm_existing = [normalize(v) for v in existing]
             norm_encoded  = normalize(encoded)
-
-            # Extract OID from definition (assumes it is the first word in parentheses)
-            def extract_oid(ldif: str) -> str:
-                return ldif.split()[0].strip('(')
-
             oid = extract_oid(atdef)
 
             # Normalize existing
diff --git a/test_manage_schema.py b/test_manage_schema.py
new file mode 100644
index 0000000..8365375
--- /dev/null
+++ b/test_manage_schema.py
@@ -0,0 +1,63 @@
+import unittest
+from unittest.mock import patch, MagicMock
+import main as manage_schema
+
+class TestManageSchema(unittest.TestCase):
+
+    def test_normalize_removes_extra_whitespace(self):
+        input_data = b'  ( 1.2.3.4  NAME   \'foo\' \n DESC \t "bar" )  '
+        expected = b'( 1.2.3.4 NAME \'foo\' DESC "bar" )'
+        self.assertEqual(manage_schema.normalize(input_data), expected)
+
+    @patch('ldap.initialize')
+    def test_existing_attribute_type_replaced(self, mock_ldap_init):
+        # Setup mock connection and search result
+        mock_conn = MagicMock()
+        mock_ldap_init.return_value = mock_conn
+
+        # Fake result for olcAttributeTypes containing old version
+        existing_attr = b"( 1.3.6.1.4.1.99999.1 NAME 'nextcloudQuota' DESC 'Old desc' SYNTAX 1.3.6.1.4.1.1466.115.121.1.27 )"
+        mock_conn.search_s.return_value = [(None, {'olcAttributeTypes': [existing_attr]})]
+
+        # Call modify_s and simulate replace
+        atdef = "( 1.3.6.1.4.1.99999.1 NAME 'nextcloudQuota' DESC 'Quota for Nextcloud' SYNTAX 1.3.6.1.4.1.1466.115.121.1.27 SINGLE-VALUE )"
+        dn = "cn={0}nextcloud,cn=schema,cn=config"
+
+        # Manually test logic: normalize and modify decision
+        norm_existing = [manage_schema.normalize(existing_attr)]
+        norm_new = manage_schema.normalize(atdef.encode())
+        self.assertNotEqual(norm_existing[0], norm_new)
+
+        # Simulate replace
+        mock_conn.modify_s.reset_mock()
+        mock_conn.modify_s(dn, [(2, 'olcAttributeTypes', [atdef.encode()])])
+        mock_conn.modify_s.assert_called_once_with(
+            dn, [(2, 'olcAttributeTypes', [atdef.encode()])]
+        )
+
+    @patch('ldap.initialize')
+    def test_add_new_object_class(self, mock_ldap_init):
+        mock_conn = MagicMock()
+        mock_ldap_init.return_value = mock_conn
+
+        # No existing object classes
+        mock_conn.search_s.return_value = [(None, {'olcObjectClasses': []})]
+
+        ocdef = "( 1.3.6.1.4.1.99999.2 NAME 'nextcloudUser' DESC 'Auxiliary class' AUXILIARY MAY ( nextcloudQuota ) )"
+        encoded = ocdef.encode()
+
+        # Simulate adding
+        dn = "cn={0}nextcloud,cn=schema,cn=config"
+        mock_conn.modify_s(dn, [(0, 'olcObjectClasses', [encoded])])
+        mock_conn.modify_s.assert_called_once_with(
+            dn, [(0, 'olcObjectClasses', [encoded])]
+        )
+
+    def test_extract_oid_from_definition(self):
+        ldif = "( 1.3.6.1.4.1.99999.1 NAME 'example' DESC 'something' )"
+        oid = manage_schema.extract_oid(ldif)
+        self.assertEqual(oid, "1.3.6.1.4.1.99999.1")
+
+
+if __name__ == '__main__':
+    unittest.main()