merge

_pytest/assertion/rewrite.py

@@ -41,6 +41,7 @@ class AssertionRewritingHook(object):
     def __init__(self):
         self.session = None
         self.modules = {}
+        self._register_with_pkg_resources()
 
     def set_session(self, session):
         self.fnpats = session.config.getini("python_files")
@@ -169,6 +170,24 @@ class AssertionRewritingHook(object):
         tp = desc[2]
         return tp == imp.PKG_DIRECTORY
 
+    @classmethod
+    def _register_with_pkg_resources(cls):
+        """
+        Ensure package resources can be loaded from this loader. May be called
+        multiple times, as the operation is idempotent.
+        """
+        try:
+            import pkg_resources
+            # access an attribute in case a deferred importer is present
+            pkg_resources.__name__
+        except ImportError:
+            return
+
+        # Since pytest tests are always located in the file system, the
+        #  DefaultProvider is appropriate.
+        pkg_resources.register_loader_type(cls, pkg_resources.DefaultProvider)
+
+
 def _write_pyc(state, co, source_path, pyc):
     # Technically, we don't have to have the same pyc format as
     # (C)Python, since these "pycs" should never be seen by builtin

testing/test_assertrewrite.py

@@ -493,3 +493,35 @@ def test_rewritten():
             raise e
         monkeypatch.setattr(b, "open", open)
         assert not _write_pyc(state, [1], source_path, pycpath)
+
+    def test_resources_provider_for_loader(self, testdir):
+        """
+        Attempts to load resources from a package should succeed normally,
+        even when the AssertionRewriteHook is used to load the modules.
+
+        See #366 for details.
+        """
+        pytest.importorskip("pkg_resources")
+
+        testdir.mkpydir('testpkg')
+        contents = {
+            'testpkg/test_pkg': """
+                import pkg_resources
+
+                import pytest
+                from _pytest.assertion.rewrite import AssertionRewritingHook
+
+                def test_load_resource():
+                    assert isinstance(__loader__, AssertionRewritingHook)
+                    res = pkg_resources.resource_string(__name__, 'resource.txt')
+                    res = res.decode('ascii')
+                    assert res == 'Load me please.'
+                """,
+        }
+        testdir.makepyfile(**contents)
+        testdir.maketxtfile(**{'testpkg/resource': "Load me please."})
+
+        result = testdir.runpytest()
+        result.stdout.fnmatch_lines([
+            '* 1 passed*',
+        ])