Add the __annotations__ attribute to the ClassDef object mode…

…l. (#2431)

* Add the ``__annotations__`` attribute to the ``ClassDef`` object model.

Pylint now does not emit a ``no-member`` error when accessing
``__annotations`` in the following cases:

```
class Test:
    print(__annotations__)
```

```
from typing import TypedDict

OtherTypedDict = TypedDict('OtherTypedDict', {'a': int, 'b': str})
print(OtherTypedDict.__annotations__)
```

Closes pylint-dev/pylint#7126

astroid/interpreter/objectmodel.py

@@ -492,6 +492,10 @@ def __init__(self):
 
  super().__init__()
 
+ @property
+ def attr___annotations__(self) -> node_classes.Unkown:
+ return node_classes.Unknown()
+
  @property
  def attr___module__(self):
  return node_classes.Const(self._instance.root().qname())

astroid/nodes/scoped_nodes/scoped_nodes.py

@@ -1946,7 +1946,10 @@ def implicit_locals(self):
  """
  locals_ = (("__module__", self.special_attributes.attr___module__),)
  # __qualname__ is defined in PEP3155
- locals_ += (("__qualname__", self.special_attributes.attr___qualname__),)
+ locals_ += (
+ ("__qualname__", self.special_attributes.attr___qualname__),
+ ("__annotations__", self.special_attributes.attr___annotations__),
+ )
  return locals_
 
  # pylint: disable=redefined-outer-name

tests/test_builder.py

@@ -841,12 +841,13 @@ def test_class_locals(self) -> None:
  klass1 = module["YO"]
  locals1 = klass1.locals
  keys = sorted(locals1.keys())
- assert_keys = ["__init__", "__module__", "__qualname__", "a"]
+ assert_keys = ["__annotations__", "__init__", "__module__", "__qualname__", "a"]
  self.assertEqual(keys, assert_keys)
  klass2 = module["YOUPI"]
  locals2 = klass2.locals
  keys = locals2.keys()
  assert_keys = [
+ "__annotations__",
  "__init__",
  "__module__",
  "__qualname__",

tests/test_object_model.py

@@ -855,3 +855,47 @@ def foo():
  assert wrapped.name == "foo"
  cache_info = next(ast_nodes[2].infer())
  assert isinstance(cache_info, astroid.Instance)
+
+
+def test_class_annotations() -> None:
+ """Test that the `__annotations__` attribute is avaiable in the class scope"""
+ annotations, klass_attribute = builder.extract_node(
+ """
+ class Test:
+ __annotations__ #@
+ Test.__annotations__ #@
+ """
+ )
+ # Test that `__annotations__` attribute is available in the class scope:
+ assert isinstance(annotations, nodes.Name)
+ # The `__annotations__` attribute is `Uninferable`:
+ assert next(annotations.infer()) is astroid.Uninferable
+
+ # Test that we can access the class annotations:
+ assert isinstance(klass_attribute, nodes.Attribute)
+
+
+def test_class_annotations_typed_dict() -> None:
+ """Test that we can access class annotations on various TypedDicts"""
+ apple, pear = builder.extract_node(
+ """
+ from typing import TypedDict
+
+
+ class Apple(TypedDict):
+ a: int
+ b: str
+
+
+ Pear = TypedDict('OtherTypedDict', {'a': int, 'b': str})
+
+
+ Apple.__annotations__ #@
+ Pear.__annotations__ #@
+ """
+ )
+
+ assert isinstance(apple, nodes.Attribute)
+ assert next(apple.infer()) is astroid.Uninferable
+ assert isinstance(pear, nodes.Attribute)
+ assert next(pear.infer()) is astroid.Uninferable

tests/test_scoped_nodes.py

@@ -1209,6 +1209,7 @@ def registered(cls, application):
  astroid = builder.parse(data, __name__)
  cls = astroid["WebAppObject"]
  assert_keys = [
+ "__annotations__",
  "__module__",
  "__qualname__",
  "appli",