Fix collection of staticmethods defined with functools.partial

Related to #5701

Author: graingert

changelog/5701.bugfix.rst

@@ -0,0 +1 @@
+Fix collection of ``staticmethod`` objects defined with ``functools.partial``.

src/_pytest/compat.py

@@ -78,7 +78,7 @@ def num_mock_patch_args(function):
     )
 
 
-def getfuncargnames(function, is_method=False, cls=None):
+def getfuncargnames(function, *, name: str = "", is_method=False, cls=None):
     """Returns the names of a function's mandatory arguments.
 
     This should return the names of all function arguments that:
@@ -91,11 +91,12 @@ def getfuncargnames(function, is_method=False, cls=None):
     be treated as a bound method even though it's not unless, only in
     the case of cls, the function is a static method.
 
+    The name parameter should be the original name in which the function was collected.
+
     @RonnyPfannschmidt: This function should be refactored when we
     revisit fixtures. The fixture mechanism should ask the node for
     the fixture names, and not try to obtain directly from the
     function object well after collection has occurred.
-
     """
     # The parameters attribute of a Signature object contains an
     # ordered mapping of parameter names to Parameter instances.  This
@@ -118,11 +119,14 @@ def getfuncargnames(function, is_method=False, cls=None):
         )
         and p.default is Parameter.empty
     )
+    if not name:
+        name = function.__name__
+
     # If this function should be treated as a bound method even though
     # it's passed as an unbound method or function, remove the first
     # parameter name.
     if is_method or (
-        cls and not isinstance(cls.__dict__.get(function.__name__, None), staticmethod)
+        cls and not isinstance(cls.__dict__.get(name, None), staticmethod)
     ):
         arg_names = arg_names[1:]
     # Remove any names that will be replaced with mocks.
@@ -245,7 +249,7 @@ def get_real_method(obj, holder):
     try:
         is_method = hasattr(obj, "__func__")
         obj = get_real_func(obj)
-    except Exception:
+    except Exception:  # pragma: no cover
         return obj
     if is_method and hasattr(obj, "__get__") and callable(obj.__get__):
         obj = obj.__get__(holder)

src/_pytest/fixtures.py

@@ -828,7 +828,7 @@ def __init__(
             where=baseid,
         )
         self.params = params
-        self.argnames = getfuncargnames(func, is_method=unittest)
+        self.argnames = getfuncargnames(func, name=argname, is_method=unittest)
         self.unittest = unittest
         self.ids = ids
         self._finalizers = []
@@ -1143,7 +1143,7 @@ def _get_direct_parametrize_args(self, node):
 
     def getfixtureinfo(self, node, func, cls, funcargs=True):
         if funcargs and not getattr(node, "nofuncargs", False):
-            argnames = getfuncargnames(func, cls=cls)
+            argnames = getfuncargnames(func, name=node.name, cls=cls)
         else:
             argnames = ()
 

testing/python/collect.py

@@ -1143,52 +1143,6 @@ class Test(object):
     assert result.ret == ExitCode.NO_TESTS_COLLECTED
 
 
-def test_collect_functools_partial(testdir):
-    """
-    Test that collection of functools.partial object works, and arguments
-    to the wrapped functions are dealt with correctly (see #811).
-    """
-    testdir.makepyfile(
-        """
-        import functools
-        import pytest
-
-        @pytest.fixture
-        def fix1():
-            return 'fix1'
-
-        @pytest.fixture
-        def fix2():
-            return 'fix2'
-
-        def check1(i, fix1):
-            assert i == 2
-            assert fix1 == 'fix1'
-
-        def check2(fix1, i):
-            assert i == 2
-            assert fix1 == 'fix1'
-
-        def check3(fix1, i, fix2):
-            assert i == 2
-            assert fix1 == 'fix1'
-            assert fix2 == 'fix2'
-
-        test_ok_1 = functools.partial(check1, i=2)
-        test_ok_2 = functools.partial(check1, i=2, fix1='fix1')
-        test_ok_3 = functools.partial(check1, 2)
-        test_ok_4 = functools.partial(check2, i=2)
-        test_ok_5 = functools.partial(check3, i=2)
-        test_ok_6 = functools.partial(check3, i=2, fix1='fix1')
-
-        test_fail_1 = functools.partial(check2, 2)
-        test_fail_2 = functools.partial(check3, 2)
-    """
-    )
-    result = testdir.inline_run()
-    result.assertoutcome(passed=6, failed=2)
-
-
 @pytest.mark.filterwarnings("default")
 def test_dont_collect_non_function_callable(testdir):
     """Test for issue https://github.com/pytest-dev/pytest/issues/331

testing/python/fixtures.py

@@ -10,7 +10,9 @@
 from _pytest.warnings import SHOW_PYTEST_WARNINGS_ARG
 
 
-def test_getfuncargnames():
+def test_getfuncargnames_functions():
+    """Test getfuncargnames for normal functions"""
+
     def f():
         pass
 
@@ -31,18 +33,56 @@ def j(arg1, arg2, arg3="hello"):
 
     assert fixtures.getfuncargnames(j) == ("arg1", "arg2")
 
+
+def test_getfuncargnames_methods():
+    """Test getfuncargnames for normal methods"""
+
     class A:
         def f(self, arg1, arg2="hello"):
             pass
 
+    assert fixtures.getfuncargnames(A().f) == ("arg1",)
+
+
+def test_getfuncargnames_staticmethod():
+    """Test getfuncargnames for staticmethods"""
+
+    class A:
         @staticmethod
-        def static(arg1, arg2):
+        def static(arg1, arg2, x=1):
             pass
 
-    assert fixtures.getfuncargnames(A().f) == ("arg1",)
     assert fixtures.getfuncargnames(A.static, cls=A) == ("arg1", "arg2")
 
 
+def test_getfuncargnames_partial():
+    """Check getfuncargnames for methods defined with functools.partial (#5701)"""
+    import functools
+
+    def check(arg1, arg2, i):
+        pass
+
+    class T:
+        test_ok = functools.partial(check, i=2)
+
+    values = fixtures.getfuncargnames(T().test_ok, name="test_ok")
+    assert values == ("arg1", "arg2")
+
+
+def test_getfuncargnames_staticmethod_partial():
+    """Check getfuncargnames for staticmethods defined with functools.partial (#5701)"""
+    import functools
+
+    def check(arg1, arg2, i):
+        pass
+
+    class T:
+        test_ok = staticmethod(functools.partial(check, i=2))
+
+    values = fixtures.getfuncargnames(T().test_ok, name="test_ok")
+    assert values == ("arg1", "arg2")
+
+
 @pytest.mark.pytester_example_path("fixtures/fill_fixtures")
 class TestFillFixtures:
     def test_fillfuncargs_exposed(self):

testing/test_compat.py

@@ -1,4 +1,5 @@
 import sys
+from functools import partial
 from functools import wraps
 
 import pytest
@@ -72,6 +73,16 @@ def func():
     assert get_real_func(wrapped_func2) is wrapped_func
 
 
+def test_get_real_func_partial():
+    """Test get_real_func handles partial instances correctly"""
+
+    def foo(x):
+        return x
+
+    assert get_real_func(foo) is foo
+    assert get_real_func(partial(foo)) is foo
+
+
 def test_is_generator_asyncio(testdir):
     testdir.makepyfile(
         """