Add separate test file for fixtures' return annotations

Author: kianelbo

testing/python/fixtures_return_annotation.py

@@ -0,0 +1,110 @@
+from collections.abc import Callable
+from typing import Any
+
+from _pytest.config import ExitCode
+from _pytest.fixtures import get_return_annotation
+from _pytest.pytester import Pytester
+
+
+class TestGetReturnAnnotation:
+    def test_primitive_return_type(self):
+        def six() -> int:
+            return 6
+
+        assert get_return_annotation(six) == "int"
+
+    def test_compound_return_type(self):
+        def two_sixes() -> tuple[int, str]:
+            return (6, "six")
+
+        assert get_return_annotation(two_sixes) == "tuple[int, str]"
+
+    def test_callable_return_type(self):
+        def callable_return() -> Callable[..., Any]:
+            return self.test_compound_return_type
+
+        assert get_return_annotation(callable_return) == "Callable[..., Any]"
+
+    def test_no_annotation(self):
+        def no_annotation():
+            return 6
+
+        assert get_return_annotation(no_annotation) == ""
+
+    def test_none_return_type(self):
+        def none_return() -> None:
+            pass
+
+        assert get_return_annotation(none_return) == "None"
+
+    def test_custom_class_return_type(self):
+        class T:
+            pass
+
+        def class_return() -> T:
+            return T()
+
+        assert get_return_annotation(class_return) == "T"
+
+    def test_enum_return_type(self):
+        def enum_return() -> ExitCode:
+            return ExitCode(0)
+
+        assert get_return_annotation(enum_return) == "ExitCode"
+
+    def test_with_arg_annotations(self):
+        def with_args(a: Callable[[], None], b: list) -> range:
+            return range(2)
+
+        assert get_return_annotation(with_args) == "range"
+
+    def test_invalid_return_type(self):
+        def bad_annotation() -> 6: # type: ignore
+            return 6
+
+        assert get_return_annotation(bad_annotation) == "6"
+
+    def test_unobtainable_signature(self):
+        assert get_return_annotation(len) == ""
+
+
+def test_fixtures_return_annotation(pytester: Pytester) -> None:
+    p = pytester.makepyfile(
+        """
+        import pytest
+        @pytest.fixture
+        def six() -> int:
+            return 6
+    """
+    )
+    result = pytester.runpytest("--fixtures", p)
+    result.stdout.fnmatch_lines(
+        """
+        *fixtures defined from*
+        *six -> int -- test_fixtures_return_annotation.py:3*
+    """
+    )
+
+
+def test_fixtures_per_test_return_annotation(pytester: Pytester) -> None:
+    p = pytester.makepyfile(
+        """
+        import pytest
+        @pytest.fixture
+        def five() -> int:
+            return 5
+        def test_five(five):
+            pass
+    """
+    )
+
+    result = pytester.runpytest("--fixtures-per-test", p)
+    assert result.ret == 0
+
+    result.stdout.fnmatch_lines(
+        [
+            "*fixtures used by test_five*",
+            "*(test_fixtures_per_test_return_annotation.py:6)*",
+            "five -> int -- test_fixtures_per_test_return_annotation.py:3",
+        ]
+    )