Some tests in importlib.test.source.test_abc_loader were testing what happens

when a loader is given missing or bad code object bytecode. Unfortunately an
exception related to source paths was masking what the proper exception to test
should be. Making the test explicitly set the environment fixed the test.

The code being test was not affected.

Lib/importlib/test/source/test_abc_loader.py

@@ -348,19 +348,27 @@ class BadBytecodeFailureTests(unittest.TestCase):
         # A bad magic number should lead to an ImportError.
         name = 'mod'
         bad_magic = b'\x00\x00\x00\x00'
-        mock = PyPycLoaderMock({}, {name: {'path': os.path.join('path', 'to',
-                                                                'mod'),
-                                            'magic': bad_magic}})
+        bc = {name:
+                {'path': os.path.join('path', 'to', 'mod'),
+                 'magic': bad_magic}}
+        mock = PyPycLoaderMock({name: None}, bc)
         with util.uncache(name), self.assertRaises(ImportError):
             mock.load_module(name)
 
+    def test_no_bytecode(self):
+        # Missing code object bytecode should lead to an EOFError.
+        name = 'mod'
+        bc = {name: {'path': os.path.join('path', 'to', 'mod'), 'bc': b''}}
+        mock = PyPycLoaderMock({name: None}, bc)
+        with util.uncache(name), self.assertRaises(EOFError):
+            mock.load_module(name)
+
     def test_bad_bytecode(self):
-        # Bad code object bytecode should lead to an ImportError.
+        # Malformed code object bytecode should lead to a ValueError.
         name = 'mod'
-        mock = PyPycLoaderMock({}, {name: {'path': os.path.join('path', 'to',
-                                                                'mod'),
-                                            'bc': b''}})
-        with util.uncache(name), self.assertRaises(ImportError):
+        bc = {name: {'path': os.path.join('path', 'to', 'mod'), 'bc': b'XXX'}}
+        mock = PyPycLoaderMock({name: None}, bc)
+        with util.uncache(name), self.assertRaises(ValueError):
             mock.load_module(name)
 
 

Misc/NEWS

@@ -88,6 +88,10 @@ Build
 Tests
 -----
 
+- Fixed tests in importlib.test.source.test_abc_loader that were masking
+  the proper exceptions that should be raised for missing or improper code
+  object bytecode.
+
 - Removed importlib's custom test discovery code and switched to
     unittest.TestLoader.discover().