Add optional namespace arguments for make_class (#1203)

* feat(make_class): add optional namespace arguments to pass through to
`make_class`

Signed-off-by: Aaron <29749331+aarnphm@users.noreply.github.com>

* chore: add changelog

Signed-off-by: Aaron <29749331+aarnphm@users.noreply.github.com>

* Rename `namespaces` to `class_body`

Signed-off-by: Aaron <29749331+aarnphm@users.noreply.github.com>

* Fix versionchanged for correct features

Signed-off-by: Aaron <29749331+aarnphm@users.noreply.github.com>

* Correctly name test case

Signed-off-by: Aaron <29749331+aarnphm@users.noreply.github.com>

* Update changelog

Signed-off-by: Aaron <29749331+aarnphm@users.noreply.github.com>

* Adjust changelog

---------

Signed-off-by: Aaron <29749331+aarnphm@users.noreply.github.com>
Co-authored-by: Hynek Schlawack <hs@ox.cx>

Author: aarnphm

changelog.d/1203.change.md

@@ -0,0 +1,2 @@
+Added *class_body* argument to `attrs.make_class()` to provide additional attributes for newly created classes.
+It is, for example, now possible to attach methods.

src/attr/__init__.pyi

@@ -490,6 +490,7 @@ def make_class(
     name: str,
     attrs: Union[List[str], Tuple[str, ...], Dict[str, Any]],
     bases: Tuple[type, ...] = ...,
+    class_body: Optional[Dict[str, Any]] = ...,
     repr_ns: Optional[str] = ...,
     repr: bool = ...,
     cmp: Optional[_EqOrderType] = ...,

src/attr/_make.py

@@ -2867,7 +2867,9 @@ def __setstate__(self, state):
 Factory = _add_hash(_add_eq(_add_repr(Factory, attrs=_f), attrs=_f), attrs=_f)
 
 
-def make_class(name, attrs, bases=(object,), **attributes_arguments):
+def make_class(
+    name, attrs, bases=(object,), class_body=None, **attributes_arguments
+):
     r"""
     A quick way to create a new class called *name* with *attrs*.
 
@@ -2883,13 +2885,16 @@ def make_class(name, attrs, bases=(object,), **attributes_arguments):
 
     :param tuple bases: Classes that the new class will subclass.
 
+    :param dict class_body: An optional dictionary of class attributes for the new class.
+
     :param attributes_arguments: Passed unmodified to `attr.s`.
 
     :return: A new class with *attrs*.
     :rtype: type
 
     .. versionadded:: 17.1.0 *bases*
     .. versionchanged:: 18.1.0 If *attrs* is ordered, the order is retained.
+    .. versionchanged:: 23.2.0 *class_body*
     """
     if isinstance(attrs, dict):
         cls_dict = attrs
@@ -2904,6 +2909,8 @@ def make_class(name, attrs, bases=(object,), **attributes_arguments):
     user_init = cls_dict.pop("__init__", None)
 
     body = {}
+    if class_body is not None:
+        body.update(class_body)
     if pre_init is not None:
         body["__attrs_pre_init__"] = pre_init
     if post_init is not None:

tests/test_make.py

@@ -1106,6 +1106,18 @@ class D:
         assert D in cls.__mro__
         assert isinstance(cls(), D)
 
+    def test_additional_class_body(self):
+        """
+        Additional class_body is added to newly created class.
+        """
+
+        def echo_func(cls, *args):
+            return args
+
+        cls = make_class("C", {}, class_body={"echo": classmethod(echo_func)})
+
+        assert ("a", "b") == cls.echo("a", "b")
+
     def test_clean_class(self, slots):
         """
         Attribute definitions do not appear on the class body.