Issue #15168: Move importlb.test to test.test_importlib.

This should make the Linux distros happy as it is now easier to leave
importlib's tests out of their base Python distribution.

Lib/test/test_importlib/builtin/test_loader.py

@@ -0,0 +1,105 @@
+import importlib
+from importlib import machinery
+from .. import abc
+from .. import util
+from . import util as builtin_util
+
+import sys
+import types
+import unittest
+
+
+class LoaderTests(abc.LoaderTests):
+
+    """Test load_module() for built-in modules."""
+
+    verification = {'__name__': 'errno', '__package__': '',
+                    '__loader__': machinery.BuiltinImporter}
+
+    def verify(self, module):
+        """Verify that the module matches against what it should have."""
+        self.assertIsInstance(module, types.ModuleType)
+        for attr, value in self.verification.items():
+            self.assertEqual(getattr(module, attr), value)
+        self.assertIn(module.__name__, sys.modules)
+
+    load_module = staticmethod(lambda name:
+                                machinery.BuiltinImporter.load_module(name))
+
+    def test_module(self):
+        # Common case.
+        with util.uncache(builtin_util.NAME):
+            module = self.load_module(builtin_util.NAME)
+            self.verify(module)
+
+    def test_package(self):
+        # Built-in modules cannot be a package.
+        pass
+
+    def test_lacking_parent(self):
+        # Built-in modules cannot be a package.
+        pass
+
+    def test_state_after_failure(self):
+        # Not way to force an imoprt failure.
+        pass
+
+    def test_module_reuse(self):
+        # Test that the same module is used in a reload.
+        with util.uncache(builtin_util.NAME):
+            module1 = self.load_module(builtin_util.NAME)
+            module2 = self.load_module(builtin_util.NAME)
+            self.assertIs(module1, module2)
+
+    def test_unloadable(self):
+        name = 'dssdsdfff'
+        assert name not in sys.builtin_module_names
+        with self.assertRaises(ImportError) as cm:
+            self.load_module(name)
+        self.assertEqual(cm.exception.name, name)
+
+    def test_already_imported(self):
+        # Using the name of a module already imported but not a built-in should
+        # still fail.
+        assert hasattr(importlib, '__file__')  # Not a built-in.
+        with self.assertRaises(ImportError) as cm:
+            self.load_module('importlib')
+        self.assertEqual(cm.exception.name, 'importlib')
+
+
+class InspectLoaderTests(unittest.TestCase):
+
+    """Tests for InspectLoader methods for BuiltinImporter."""
+
+    def test_get_code(self):
+        # There is no code object.
+        result = machinery.BuiltinImporter.get_code(builtin_util.NAME)
+        self.assertIsNone(result)
+
+    def test_get_source(self):
+        # There is no source.
+        result = machinery.BuiltinImporter.get_source(builtin_util.NAME)
+        self.assertIsNone(result)
+
+    def test_is_package(self):
+        # Cannot be a package.
+        result = machinery.BuiltinImporter.is_package(builtin_util.NAME)
+        self.assertTrue(not result)
+
+    def test_not_builtin(self):
+        # Modules not built-in should raise ImportError.
+        for meth_name in ('get_code', 'get_source', 'is_package'):
+            method = getattr(machinery.BuiltinImporter, meth_name)
+        with self.assertRaises(ImportError) as cm:
+            method(builtin_util.BAD_NAME)
+        self.assertRaises(builtin_util.BAD_NAME)
+
+
+
+def test_main():
+    from test.support import run_unittest
+    run_unittest(LoaderTests, InspectLoaderTests)
+
+
+if __name__ == '__main__':
+    test_main()