Fix InferType and improve type-checker tests

hypothesis-python/RELEASE.rst

@@ -0,0 +1,5 @@
+RELEASE_TYPE: patch
+
+This patch fixes type annotations that had caused the signature of 
+:func:`@given <hypothesis.given>` to be partially-unknown to type-checkers for Python 
+versions before 3.10.

hypothesis-python/src/hypothesis/core.py

@@ -25,6 +25,7 @@
 from itertools import chain
 from random import Random
 from typing import (
+    TYPE_CHECKING,
     Any,
     BinaryIO,
     Callable,
@@ -114,7 +115,8 @@
 
 if sys.version_info >= (3, 10):  # pragma: no cover
     from types import EllipsisType as InferType
-
+elif TYPE_CHECKING:
+    from builtins import ellipsis as InferType
 else:
     InferType = type(Ellipsis)
 

hypothesis-python/src/hypothesis/extra/django/_impl.py

@@ -12,7 +12,7 @@
 import unittest
 from functools import partial
 from inspect import Parameter, signature
-from typing import Optional, Type, Union
+from typing import TYPE_CHECKING, Optional, Type, Union
 
 from django import forms as df, test as dt
 from django.contrib.staticfiles import testing as dst
@@ -28,7 +28,8 @@
 
 if sys.version_info >= (3, 10):  # pragma: no cover
     from types import EllipsisType as InferType
-
+elif TYPE_CHECKING:
+    from builtins import ellipsis as InferType
 else:
     InferType = type(Ellipsis)
 

hypothesis-python/src/hypothesis/extra/ghostwriter.py

@@ -83,6 +83,7 @@
 from string import ascii_lowercase
 from textwrap import dedent, indent
 from typing import (
+    TYPE_CHECKING,
     Any,
     Callable,
     Dict,
@@ -119,7 +120,8 @@
 
 if sys.version_info >= (3, 10):  # pragma: no cover
     from types import EllipsisType as InferType
-
+elif TYPE_CHECKING:
+    from builtins import ellipsis as InferType
 else:
     InferType = type(Ellipsis)
 

hypothesis-python/src/hypothesis/strategies/_internal/core.py

@@ -109,7 +109,8 @@
 
 if sys.version_info >= (3, 10):  # pragma: no cover
     from types import EllipsisType as InferType
-
+elif typing.TYPE_CHECKING:  # pragma: no cover
+    from builtins import ellipsis as InferType
 else:
     InferType = type(Ellipsis)
 

requirements/tools.txt

@@ -236,7 +236,7 @@ pygments==2.12.0
     #   sphinx
 pyparsing==3.0.9
     # via packaging
-pyright==1.1.249
+pyright==1.1.255
     # via -r requirements/tools.in
 pytest==7.1.2
     # via -r requirements/tools.in

whole-repo-tests/test_mypy.py

@@ -16,6 +16,8 @@
 from hypothesistooling.projects.hypothesispython import PYTHON_SRC
 from hypothesistooling.scripts import pip_tool, tool_path
 
+PYTHON_VERSIONS = ["3.7", "3.8", "3.9", "3.10", "3.11"]
+
 
 def test_mypy_passes_on_hypothesis():
     pip_tool("mypy", PYTHON_SRC)
@@ -56,14 +58,20 @@ def get_mypy_analysed_type(fname, val):
     )
 
 
-def assert_mypy_errors(fname, expected):
-    out = get_mypy_output(fname, "--no-error-summary", "--show-error-codes")
+def assert_mypy_errors(fname, expected, python_version=None):
+    _args = ["--no-error-summary", "--show-error-codes"]
+
+    if python_version:
+        _args.append(f"--python-version={python_version}")
+
+    out = get_mypy_output(fname, *_args)
+    del _args
     # Shell output looks like:
     # file.py:2: error: Incompatible types in assignment ... [assignment]
 
     def convert_lines():
         for error_line in out.splitlines():
-            col, category = error_line.split(":")[1:3]
+            col, category = error_line.split(":")[-3:-1]
             if category.strip() != "error":
                 # mypy outputs "note" messages for overload problems, even with
                 # --hide-error-context. Don't include these
@@ -343,23 +351,6 @@ def test_stateful_consumed_bundle_cannot_be_target(tmpdir):
     assert_mypy_errors(str(f.realpath()), [(3, "call-overload")])
 
 
-def test_raises_for_mixed_pos_kwargs_in_given(tmpdir):
-    f = tmpdir.join("raises_for_mixed_pos_kwargs_in_given.py")
-    f.write(
-        textwrap.dedent(
-            """
-            from hypothesis import given
-            from hypothesis.strategies import text
-
-            @given(text(), x=text())
-            def test_bar(x):
-                ...
-            """
-        )
-    )
-    assert_mypy_errors(str(f.realpath()), [(5, "call-overload")])
-
-
 @pytest.mark.parametrize(
     "return_val,errors",
     [
@@ -445,3 +436,67 @@ def test_pos_only_args(tmpdir):
             (8, "call-overload"),
         ],
     )
+
+
+@pytest.mark.parametrize("python_version", PYTHON_VERSIONS)
+def test_mypy_passes_on_basic_test(tmpdir, python_version):
+    f = tmpdir.join("check_mypy_on_basic_tests.py")
+    f.write(
+        textwrap.dedent(
+            """
+            import hypothesis
+            import hypothesis.strategies as st
+
+            @hypothesis.given(x=st.text())
+            def test_foo(x: str) -> None:
+                assert x == x
+
+            from hypothesis import given
+            from hypothesis.strategies import text
+
+            @given(x=text())
+            def test_bar(x: str) -> None:
+                assert x == x
+            """
+        )
+    )
+    assert_mypy_errors(str(f.realpath()), [], python_version=python_version)
+
+
+@pytest.mark.parametrize("python_version", PYTHON_VERSIONS)
+def test_given_only_allows_strategies(tmpdir, python_version):
+    f = tmpdir.join("check_mypy_given_expects_strategies.py")
+    f.write(
+        textwrap.dedent(
+            """
+            from hypothesis import given
+
+            @given(1)
+            def f():
+                pass
+            """
+        )
+    )
+    assert_mypy_errors(
+        str(f.realpath()), [(4, "call-overload")], python_version=python_version
+    )
+
+
+@pytest.mark.parametrize("python_version", PYTHON_VERSIONS)
+def test_raises_for_mixed_pos_kwargs_in_given(tmpdir, python_version):
+    f = tmpdir.join("raises_for_mixed_pos_kwargs_in_given.py")
+    f.write(
+        textwrap.dedent(
+            """
+            from hypothesis import given
+            from hypothesis.strategies import text
+
+            @given(text(), x=text())
+            def test_bar(x):
+                ...
+            """
+        )
+    )
+    assert_mypy_errors(
+        str(f.realpath()), [(5, "call-overload")], python_version=python_version
+    )

whole-repo-tests/test_pyright.py

@@ -21,6 +21,8 @@
 from hypothesistooling.projects.hypothesispython import HYPOTHESIS_PYTHON, PYTHON_SRC
 from hypothesistooling.scripts import pip_tool, tool_path
 
+PYTHON_VERSIONS = ["3.7", "3.8", "3.9", "3.10", "3.11"]
+
 
 @pytest.mark.skip(
     reason="Hypothesis type-annotates the public API as a convenience for users, "
@@ -30,7 +32,8 @@ def test_pyright_passes_on_hypothesis():
     pip_tool("pyright", "--project", HYPOTHESIS_PYTHON)
 
 
-def test_pyright_passes_on_basic_test(tmp_path: Path):
+@pytest.mark.parametrize("python_version", PYTHON_VERSIONS)
+def test_pyright_passes_on_basic_test(tmp_path: Path, python_version: str):
     file = tmp_path / "test.py"
     file.write_text(
         textwrap.dedent(
@@ -51,10 +54,40 @@ def test_bar(x: str):
             """
         )
     )
-    _write_config(tmp_path, {"typeCheckingMode": "strict"})
+    _write_config(
+        tmp_path, {"typeCheckingMode": "strict", "pythonVersion": python_version}
+    )
     assert _get_pyright_errors(file) == []
 
 
+@pytest.mark.parametrize("python_version", PYTHON_VERSIONS)
+def test_given_only_allows_strategies(tmp_path: Path, python_version: str):
+    file = tmp_path / "test.py"
+    file.write_text(
+        textwrap.dedent(
+            """
+            from hypothesis import given
+
+            @given(1)
+            def f():
+                pass
+            """
+        )
+    )
+    _write_config(
+        tmp_path, {"typeCheckingMode": "strict", "pythonVersion": python_version}
+    )
+    assert (
+        sum(
+            e["message"].startswith(
+                'Argument of type "Literal[1]" cannot be assigned to parameter "_given_arguments"'
+            )
+            for e in _get_pyright_errors(file)
+        )
+        == 1
+    )
+
+
 def test_pyright_issue_3296(tmp_path: Path):
     file = tmp_path / "test.py"
     file.write_text(
@@ -85,9 +118,14 @@ def test_bar(x: str):
         )
     )
     _write_config(tmp_path, {"typeCheckingMode": "strict"})
-    assert any(
-        e["message"].startswith('No overloads for "given" match the provided arguments')
-        for e in _get_pyright_errors(file)
+    assert (
+        sum(
+            e["message"].startswith(
+                'No overloads for "given" match the provided arguments'
+            )
+            for e in _get_pyright_errors(file)
+        )
+        == 1
     )
 
 
@@ -122,11 +160,14 @@ def test_pyright_tuples_pos_args_only(tmp_path: Path):
         )
     )
     _write_config(tmp_path, {"typeCheckingMode": "strict"})
-    assert any(
-        e["message"].startswith(
-            'No overloads for "tuples" match the provided arguments'
+    assert (
+        sum(
+            e["message"].startswith(
+                'No overloads for "tuples" match the provided arguments'
+            )
+            for e in _get_pyright_errors(file)
         )
-        for e in _get_pyright_errors(file)
+        == 2
     )
 
 
@@ -143,11 +184,14 @@ def test_pyright_one_of_pos_args_only(tmp_path: Path):
         )
     )
     _write_config(tmp_path, {"typeCheckingMode": "strict"})
-    assert any(
-        e["message"].startswith(
-            'No overloads for "one_of" match the provided arguments'
+    assert (
+        sum(
+            e["message"].startswith(
+                'No overloads for "one_of" match the provided arguments'
+            )
+            for e in _get_pyright_errors(file)
         )
-        for e in _get_pyright_errors(file)
+        == 2
     )