Merge pull request #2158 from GrigoriosGiann/add-supports-index

Add support for `SupportsIndex` in Python 3.8

hypothesis-python/RELEASE.rst

@@ -0,0 +1,6 @@
+RELEASE_TYPE: patch
+
+Python 3.8's new :class:`python:typing.SupportsIndex` type - see :pep:`357`
+for details - is now  supported in :func:`~hypothesis.strategies.from_type`.
+
+Thanks to Grigorios Giannakopoulos for the patch!

hypothesis-python/src/hypothesis/searchstrategy/types.py

@@ -238,6 +238,9 @@ def from_typing_type(thing):
         array_shapes,
         scalar_dtypes,
         nested_dtypes,
+        from_dtype,
+        integer_dtypes,
+        unsigned_integer_dtypes,
     )
 
     _global_type_lookup.update(
@@ -247,7 +250,7 @@ def from_typing_type(thing):
         }
     )
 except ImportError:  # pragma: no cover
-    pass
+    np = None
 
 try:
     import typing
@@ -275,6 +278,13 @@ def from_typing_type(thing):
         _global_type_lookup[typing.SupportsRound] = st.complex_numbers()
     except AttributeError:  # pragma: no cover
         pass
+    try:
+        strat = st.integers() | st.booleans()
+        if np is not None:  # pragma: no branch
+            strat |= (unsigned_integer_dtypes() | integer_dtypes()).flatmap(from_dtype)
+        _global_type_lookup[typing.SupportsIndex] = strat  # type: ignore
+    except AttributeError:  # pragma: no cover
+        pass
 
     def register(type_, fallback=None):
         if isinstance(type_, str):

hypothesis-python/tests/py3/test_lookup.py

@@ -232,6 +232,13 @@ def inner_3(ex):
         st.from_type.__clear_cache()
 
 
+def if_available(name):
+    try:
+        return getattr(typing, name)
+    except AttributeError:
+        return pytest.param(name, marks=[pytest.mark.skip])
+
+
 @pytest.mark.parametrize(
     "typ",
     [
@@ -245,6 +252,7 @@ def inner_3(ex):
         typing.SupportsFloat,
         typing.SupportsInt,
         typing.SupportsRound,
+        if_available("SupportsIndex"),
     ],
 )
 def test_resolves_weird_types(typ):