In 3.7, namespace modules can have: mod.__file__ is None

Backport of c9f4f661ccb7decb55055d80a1e9a1cbb825b27f

2 files changed, 17 insertions, 8 deletions

diff --git a/coverage/control.py b/coverage/control.py
index b82c8047..cf65d658 100644
--- a/coverage/control.py
+++ b/coverage/control.py
@@ -855,8 +855,7 @@ class Coverage(object):
         # Find files that were never executed at all.
         for pkg in self.source_pkgs:
             if (not pkg in sys.modules or
-                not hasattr(sys.modules[pkg], '__file__') or
-                not os.path.exists(sys.modules[pkg].__file__)):
+                not module_has_file(sys.modules[pkg])):
                 continue
             pkg_file = source_for_file(sys.modules[pkg].__file__)
             self._find_unexecuted_files(self._canonical_path(pkg_file))
@@ -878,15 +877,12 @@ class Coverage(object):
             self._warn("Module %s was never imported." % pkg, slug="module-not-imported")
             return
 
-        is_namespace = hasattr(mod, '__path__') and not hasattr(mod, '__file__')
-        has_file = hasattr(mod, '__file__') and os.path.exists(mod.__file__)
-
-        if is_namespace:
+        if module_is_namespace(mod):
             # A namespace package. It's OK for this not to have been traced,
             # since there is no code directly in it.
             return
 
-        if not has_file:
+        if not module_has_file(mod):
             self._warn("Module %s has no Python source." % pkg, slug="module-not-python")
             return
 
@@ -1204,6 +1200,19 @@ class Coverage(object):
         return info
 
 
+def module_is_namespace(mod):
+    """Is the module object `mod` a PEP420 namespace module?"""
+    return hasattr(mod, '__path__') and getattr(mod, '__file__', None) is None
+
+
+def module_has_file(mod):
+    """Does the module object `mod` have an existing __file__ ?"""
+    mod__file__ = getattr(mod, '__file__', None)
+    if mod__file__ is None:
+        return False
+    return os.path.exists(mod__file__)
+
+
 # FileDisposition "methods": FileDisposition is a pure value object, so it can
 # be implemented in either C or Python.  Acting on them is done with these
 # functions.
diff --git a/coverage/python.py b/coverage/python.py
index 372347f5..2b16acab 100644
--- a/coverage/python.py
+++ b/coverage/python.py
@@ -135,7 +135,7 @@ class PythonFileReporter(FileReporter):
     def __init__(self, morf, coverage=None):
         self.coverage = coverage
 
-        if hasattr(morf, '__file__'):
+        if hasattr(morf, '__file__') and morf.__file__:
             filename = morf.__file__
         elif isinstance(morf, types.ModuleType):
             # A module should have had .__file__, otherwise we can't use it.