issue 14660: Implement PEP 420, namespace packages.

1 files changed, 239 insertions, 0 deletions

diff --git a/Lib/test/test_namespace_pkgs.py b/Lib/test/test_namespace_pkgs.py
new file mode 100644
index 0000000..176ddd3
--- /dev/null
+++ b/Lib/test/test_namespace_pkgs.py
@@ -0,0 +1,239 @@
+import sys
+import contextlib
+import unittest
+import os
+
+import importlib.test.util
+from test.support import run_unittest
+
+# needed tests:
+#
+# need to test when nested, so that the top-level path isn't sys.path
+# need to test dynamic path detection, both at top-level and nested
+# with dynamic path, check when a loader is returned on path reload (that is,
+#  trying to switch from a namespace package to a regular package)
+
+
+@contextlib.contextmanager
+def sys_modules_context():
+    """
+    Make sure sys.modules is the same object and has the same content
+    when exiting the context as when entering.
+
+    Similar to importlib.test.util.uncache, but doesn't require explicit
+    names.
+    """
+    sys_modules_saved = sys.modules
+    sys_modules_copy = sys.modules.copy()
+    try:
+        yield
+    finally:
+        sys.modules = sys_modules_saved
+        sys.modules.clear()
+        sys.modules.update(sys_modules_copy)
+
+
+@contextlib.contextmanager
+def namespace_tree_context(**kwargs):
+    """
+    Save import state and sys.modules cache and restore it on exit.
+    Typical usage:
+
+    >>> with namespace_tree_context(path=['/tmp/xxyy/portion1',
+    ...         '/tmp/xxyy/portion2']):
+    ...     pass
+    """
+    # use default meta_path and path_hooks unless specified otherwise
+    kwargs.setdefault('meta_path', sys.meta_path)
+    kwargs.setdefault('path_hooks', sys.path_hooks)
+    import_context = importlib.test.util.import_state(**kwargs)
+    with import_context, sys_modules_context():
+        yield
+
+class NamespacePackageTest(unittest.TestCase):
+    """
+    Subclasses should define self.root and self.paths (under that root)
+    to be added to sys.path.
+    """
+    root = os.path.join(os.path.dirname(__file__), 'namespace_pkgs')
+
+    def setUp(self):
+        self.resolved_paths = [
+            os.path.join(self.root, path) for path in self.paths
+        ]
+        self.ctx = namespace_tree_context(path=self.resolved_paths)
+        self.ctx.__enter__()
+
+    def tearDown(self):
+        # TODO: will we ever want to pass exc_info to __exit__?
+        self.ctx.__exit__(None, None, None)
+
+class SingleNamespacePackage(NamespacePackageTest):
+    paths = ['portion1']
+
+    def test_simple_package(self):
+        import foo.one
+        self.assertEqual(foo.one.attr, 'portion1 foo one')
+
+    def test_cant_import_other(self):
+        with self.assertRaises(ImportError):
+            import foo.two
+
+    def test_module_repr(self):
+        import foo.one
+        self.assertEqual(repr(foo), "<module 'foo' (namespace)>")
+
+
+class DynamicPatheNamespacePackage(NamespacePackageTest):
+    paths = ['portion1']
+
+    def test_dynamic_path(self):
+        # Make sure only 'foo.one' can be imported
+        import foo.one
+        self.assertEqual(foo.one.attr, 'portion1 foo one')
+
+        with self.assertRaises(ImportError):
+            import foo.two
+
+        # Now modify sys.path
+        sys.path.append(os.path.join(self.root, 'portion2'))
+
+        # And make sure foo.two is now importable
+        import foo.two
+        self.assertEqual(foo.two.attr, 'portion2 foo two')
+
+
+class CombinedNamespacePackages(NamespacePackageTest):
+    paths = ['both_portions']
+
+    def test_imports(self):
+        import foo.one
+        import foo.two
+        self.assertEqual(foo.one.attr, 'both_portions foo one')
+        self.assertEqual(foo.two.attr, 'both_portions foo two')
+
+
+class SeparatedNamespacePackages(NamespacePackageTest):
+    paths = ['portion1', 'portion2']
+
+    def test_imports(self):
+        import foo.one
+        import foo.two
+        self.assertEqual(foo.one.attr, 'portion1 foo one')
+        self.assertEqual(foo.two.attr, 'portion2 foo two')
+
+
+class SeparatedOverlappingNamespacePackages(NamespacePackageTest):
+    paths = ['portion1', 'both_portions']
+
+    def test_first_path_wins(self):
+        import foo.one
+        import foo.two
+        self.assertEqual(foo.one.attr, 'portion1 foo one')
+        self.assertEqual(foo.two.attr, 'both_portions foo two')
+
+    def test_first_path_wins_again(self):
+        sys.path.reverse()
+        import foo.one
+        import foo.two
+        self.assertEqual(foo.one.attr, 'both_portions foo one')
+        self.assertEqual(foo.two.attr, 'both_portions foo two')
+
+    def test_first_path_wins_importing_second_first(self):
+        import foo.two
+        import foo.one
+        self.assertEqual(foo.one.attr, 'portion1 foo one')
+        self.assertEqual(foo.two.attr, 'both_portions foo two')
+
+
+class SingleZipNamespacePackage(NamespacePackageTest):
+    paths = ['top_level_portion1.zip']
+
+    def test_simple_package(self):
+        import foo.one
+        self.assertEqual(foo.one.attr, 'portion1 foo one')
+
+    def test_cant_import_other(self):
+        with self.assertRaises(ImportError):
+            import foo.two
+
+
+class SeparatedZipNamespacePackages(NamespacePackageTest):
+    paths = ['top_level_portion1.zip', 'portion2']
+
+    def test_imports(self):
+        import foo.one
+        import foo.two
+        self.assertEqual(foo.one.attr, 'portion1 foo one')
+        self.assertEqual(foo.two.attr, 'portion2 foo two')
+        self.assertIn('top_level_portion1.zip', foo.one.__file__)
+        self.assertNotIn('.zip', foo.two.__file__)
+
+
+class SingleNestedZipNamespacePackage(NamespacePackageTest):
+    paths = ['nested_portion1.zip/nested_portion1']
+
+    def test_simple_package(self):
+        import foo.one
+        self.assertEqual(foo.one.attr, 'portion1 foo one')
+
+    def test_cant_import_other(self):
+        with self.assertRaises(ImportError):
+            import foo.two
+
+
+class SeparatedNestedZipNamespacePackages(NamespacePackageTest):
+    paths = ['nested_portion1.zip/nested_portion1', 'portion2']
+
+    def test_imports(self):
+        import foo.one
+        import foo.two
+        self.assertEqual(foo.one.attr, 'portion1 foo one')
+        self.assertEqual(foo.two.attr, 'portion2 foo two')
+        fn = os.path.join('nested_portion1.zip', 'nested_portion1')
+        self.assertIn(fn, foo.one.__file__)
+        self.assertNotIn('.zip', foo.two.__file__)
+
+
+class LegacySupport(NamespacePackageTest):
+    paths = ['not_a_namespace_pkg', 'portion1', 'portion2', 'both_portions']
+
+    def test_non_namespace_package_takes_precedence(self):
+        import foo.one
+        with self.assertRaises(ImportError):
+            import foo.two
+        self.assertIn('__init__', foo.__file__)
+        self.assertNotIn('namespace', str(foo.__loader__).lower())
+
+
+class ZipWithMissingDirectory(NamespacePackageTest):
+    paths = ['missing_directory.zip']
+
+    @unittest.expectedFailure
+    def test_missing_directory(self):
+        # This will fail because missing_directory.zip contains:
+        #   Length      Date    Time    Name
+        # ---------  ---------- -----   ----
+        #        29  2012-05-03 18:13   foo/one.py
+        #         0  2012-05-03 20:57   bar/
+        #        38  2012-05-03 20:57   bar/two.py
+        # ---------                     -------
+        #        67                     3 files
+
+        # Because there is no 'foo/', the zipimporter currently doesn't
+        #  know that foo is a namespace package
+
+        import foo.one
+
+    def test_present_directory(self):
+        # This succeeds because there is a "bar/" in the zip file
+        import bar.two
+        self.assertEqual(bar.two.attr, 'missing_directory foo two')
+
+
+def test_main():
+    run_unittest(*NamespacePackageTest.__subclasses__())
+
+
+if __name__ == "__main__":
+    test_main()