Get annotated types

hypothesis-python/RELEASE.rst

@@ -1,4 +1,15 @@
 RELEASE_TYPE: minor
 
-Adds ability to specify hypothesis strategies in :obj:`python:typing.Annotated`.
-Example: ``PositiveInt = Annotated[int, st.integer(min_value=1)]``
+This release teaches :func:`~hypothesis.strategies.from_type` a neat trick:
+when resolving an :obj:`python:typing.Annotated` type, if one of the annotations
+is a strategy object we use that as the inferred strategy.  For example:
+
+.. code-block:: python
+
+    PositiveInt = Annotated[int, st.integers(min_value=1)]
+
+If there are multiple strategies, we use the last outer-most annotation.
+See :issue:`2978` and :pull:`3082` for discussion.
+
+*Requires Python 3.9 or later for*
+:func:`get_type_hints(..., include_extras=False) <typing.get_type_hints>`.

hypothesis-python/src/hypothesis/internal/compat.py

@@ -81,28 +81,25 @@ def get_type_hints(thing):
     Never errors: instead of raising TypeError for uninspectable objects, or
     NameError for unresolvable forward references, just return an empty dict.
     """
+    kwargs = {} if sys.version_info[:2] < (3, 9) else {"include_extras": True}
+
     try:
-        hints = typing.get_type_hints(thing)
+        hints = typing.get_type_hints(thing, **kwargs)
     except (AttributeError, TypeError, NameError):
         hints = {}
 
     if not inspect.isclass(thing):
         return hints
 
     try:
-        hints.update(typing.get_type_hints(thing.__init__))
+        hints.update(typing.get_type_hints(thing.__init__, **kwargs))
     except (TypeError, NameError, AttributeError):
         pass
 
     try:
         if hasattr(thing, "__signature__"):
             # It is possible for the signature and annotations attributes to
             # differ on an object due to renamed arguments.
-            # To prevent missing arguments we use the signature to provide any type
-            # hints it has and then override any common names with the more
-            # comprehensive type information from get_type_hints
-            # See https://github.com/HypothesisWorks/hypothesis/pull/2580
-            # for more details.
             from hypothesis.strategies._internal.types import is_a_type
 
             vkinds = (inspect.Parameter.VAR_POSITIONAL, inspect.Parameter.VAR_KEYWORD)
@@ -112,8 +109,6 @@ def get_type_hints(thing):
                         hints[p.name] = typing.Optional[p.annotation]
                     else:
                         hints[p.name] = p.annotation
-                else:  # pragma: no cover
-                    pass
     except (AttributeError, TypeError, NameError):  # pragma: no cover
         pass
 

hypothesis-python/tests/cover/test_compat.py

@@ -14,10 +14,11 @@
 # END HEADER
 
 import math
+from inspect import Parameter, Signature
 
 import pytest
 
-from hypothesis.internal.compat import ceil, floor
+from hypothesis.internal.compat import ceil, floor, get_type_hints
 
 floor_ceil_values = [
     -10.7,
@@ -39,3 +40,13 @@ def test_our_floor_agrees_with_math_floor(value):
 @pytest.mark.parametrize("value", floor_ceil_values)
 def test_our_ceil_agrees_with_math_ceil(value):
     assert ceil(value) == math.ceil(value)
+
+
+class WeirdSig:
+    __signature__ = Signature(
+        parameters=[Parameter(name="args", kind=Parameter.VAR_POSITIONAL)]
+    )
+
+
+def test_no_type_hints():
+    assert get_type_hints(WeirdSig) == {}