fix(corekit): give unnamed ListField, PayloadField and SchemaField a default name (#1491)

ListField.__init__, PayloadField.__init__ and SchemaField.__init__ set no
_name, so .name on an unnamed instance -- and on OptionField and its
subclasses -- raised AttributeError. Default it with the hasattr idiom
FieldBase and Field already use, giving <list>, <option>, <chunklist>,
<payload>, <schema>, and so on.

Author: JarryShaw

pcapkit/corekit/fields/collections.py

@@ -96,6 +96,9 @@ def __init__(self, length: 'int | Callable[[dict[str, Any]], int]' = lambda _: -
                  item_type: 'Optional[FieldBase]' = None,
                  callback: 'Callable[[Self, dict[str, Any]], None]' = lambda *_: None) -> 'None':
         #self._name = '<list>'
+        if not hasattr(self, '_name'):
+            self._name = f'<{type(self).__name__[:-5].lower()}>'
+
         self._callback = callback
         self._item_type = item_type
 

pcapkit/corekit/fields/misc.py

@@ -307,7 +307,9 @@ def __init__(self, length: 'int | Callable[[dict[str, Any]], int]' = lambda _: -
                  default: '_TP | NoValueType | bytes' = NO_VALUE,
                  protocol: 'Optional[Type[_TP] | str]' = None,
                  callback: 'Callable[[Self, dict[str, Any]], None]' = lambda *_: None) -> 'None':
-        #self._name = '<payload>'
+        if not hasattr(self, '_name'):
+            self._name = f'<{type(self).__name__[:-5].lower()}>'
+
         self._default = default  # type: ignore[assignment]
 
         # NOTE: Through the property rather than straight to ``_protocol``, so a
@@ -652,7 +654,9 @@ def __init__(self, length: 'int | Callable[[dict[str, Any]], int]' = lambda _: -
                  default: '_TS | NoValueType | bytes' = NO_VALUE,
                  packet: 'Optional[dict[str, Any]]' = None,
                  callback: 'Callable[[Self, dict[str, Any]], None]' = lambda *_: None) -> 'None':
-        #self._name = '<schema>'
+        if not hasattr(self, '_name'):
+            self._name = f'<{type(self).__name__[:-5].lower()}>'
+
         self._callback = callback
 
         if packet is None:

tests/corekit/test_fields_collections_default_name_1491_unit.py

@@ -0,0 +1,77 @@
+# -*- coding: utf-8 -*-
+"""Unnamed collection, payload and schema fields have a default name.
+
+GitHub issue #1491: :meth:`ListField.__init__
+<pcapkit.corekit.fields.collections.ListField.__init__>` set no ``_name``, so
+``ListField().name`` raised :exc:`AttributeError` -- and so did every subclass
+that reaches it through ``super().__init__``, :class:`OptionField` included,
+whose ``unpack`` reads ``self.name``. :class:`PayloadField` and
+:class:`SchemaField` had the same gap. Other fields default to
+``<{class name less "Field", lower-cased}>``, as :class:`FieldBase` and
+:class:`Field` do in :mod:`pcapkit.corekit.fields.field`.
+
+Classes are imported inside each test, after
+:func:`~tests._support.reimport_once_per_class`.
+
+"""
+
+import unittest
+
+from tests._support import reimport_once_per_class
+
+
+class TestListFieldDefaultName(unittest.TestCase):
+    """Pin the default name of unnamed collection fields."""
+
+    def setUp(self) -> None:
+        reimport_once_per_class(self)
+
+    def test_list_field(self) -> None:
+        from pcapkit.corekit.fields.collections import ListField
+
+        self.assertEqual(ListField().name, '<list>')
+        self.assertEqual(repr(ListField()), '<ListField>')
+
+    def test_option_field_subclasses(self) -> None:
+        from pcapkit.corekit.fields.collections import OptionField
+        from pcapkit.protocols.schema.transport.sctp import ChunkListField, Parameter
+
+        for cls, name in ((OptionField, '<option>'), (ChunkListField, '<chunklist>')):
+            with self.subTest(cls=cls.__name__):
+                field = cls(base_schema=Parameter, type_name='type',
+                            registry=Parameter.registry)
+                self.assertEqual(field.name, name)
+
+    def test_copy_keeps_default_name(self) -> None:
+        from pcapkit.corekit.fields.collections import ListField
+
+        self.assertEqual(ListField()({}).name, '<list>')
+
+    def test_schema_name_wins(self) -> None:
+        from pcapkit.protocols.schema.transport.sctp import INITChunk
+
+        self.assertEqual(INITChunk.__fields__['parameters'].name, 'parameters')
+
+
+class TestMiscFieldDefaultName(unittest.TestCase):
+    """Pin the default name of unnamed :mod:`~pcapkit.corekit.fields.misc` fields."""
+
+    def setUp(self) -> None:
+        reimport_once_per_class(self)
+
+    def test_payload_field(self) -> None:
+        from pcapkit.corekit.fields.misc import PayloadField
+
+        self.assertEqual(PayloadField().name, '<payload>')
+        self.assertEqual(PayloadField()({}).name, '<payload>')
+
+    def test_schema_field(self) -> None:
+        from pcapkit.corekit.fields.misc import SchemaField
+        from pcapkit.protocols.schema.transport.sctp import Parameter
+
+        self.assertEqual(SchemaField(schema=Parameter).name, '<schema>')
+        self.assertEqual(SchemaField(schema=Parameter)({}).name, '<schema>')
+
+
+if __name__ == '__main__':
+    unittest.main()