ignore magic callables with no sane code in factory/setup discovery

CHANGELOG

@@ -44,6 +44,9 @@ Changes between 2.2.4 and 2.3.0.dev
 
 - fix issue 178: xml binary escapes are now wrapped in py.xml.raw
 
+- factory discovery no longer fails with magic global callables
+  that provide no sane __code__ object (mock.call for example)
+
 - reporting refinements:
 
   - pytest_report_header now receives a "startdir" so that

_pytest/python.py

@@ -1303,10 +1303,14 @@ class FuncargManager:
             obj = getattr(holderobj, name)
             if not callable(obj):
                 continue
+            # to avoid breaking on magic global callables
+            # we explicitly check if we get a sane code object
+            # else having mock.call in the globals fails for example
+            code = py.code.getrawcode(obj)
+            if not inspect.iscode(code):
+                continue
             # resource factories either have a pytest_funcarg__ prefix
             # or are "funcarg" marked
-            if not callable(obj):
-                continue
             marker = getattr(obj, "_pytestfactory", None)
             if marker is not None:
                 assert not name.startswith(self._argprefix)

testing/test_python.py

@@ -1761,6 +1761,23 @@ class TestSetupDiscovery:
         reprec = testdir.inline_run("-s")
         reprec.assertoutcome(passed=1)
 
+    def test_callables_nocode(self, testdir):
+        """
+        a imported mock.call would break setup/factory discovery
+        due to it being callable and __code__ not being a code object
+        """
+        testdir.makepyfile("""
+           class _call(tuple):
+               def __call__(self, *k, **kw):
+                   pass
+               def __getattr__(self, k):
+                   return self
+
+           call = _call()
+        """)
+        reprec = testdir.inline_run("-s")
+        reprec.assertoutcome(failed=0, passed=0)
+
 
 class TestSetupManagement:
     def test_funcarg_and_setup(self, testdir):