Add regression test

There's a bug in try_import that will cause this test to raise an
"NoneType has no attribute" exception.

IPython/core/tests/test_completerlib.py

@@ -1,161 +1,175 b''
 # -*- coding: utf-8 -*-
 """Tests for completerlib.
 
 """
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 import os
 import shutil
 import sys
 import tempfile
 import unittest
 from os.path import join
 
 import nose.tools as nt
 
-from IPython.core.completerlib import magic_run_completer, module_completion
+from IPython.core.completerlib import magic_run_completer, module_completion, try_import
 from IPython.utils.tempdir import TemporaryDirectory
 from IPython.testing.decorators import onlyif_unicode_paths
 
 
 class MockEvent(object):
     def __init__(self, line):
         self.line = line
 
 #-----------------------------------------------------------------------------
 # Test functions begin
 #-----------------------------------------------------------------------------
 class Test_magic_run_completer(unittest.TestCase):
     files = [u"aao.py", u"a.py", u"b.py", u"aao.txt"]
     dirs = [u"adir/", "bdir/"]
 
     def setUp(self):
         self.BASETESTDIR = tempfile.mkdtemp()
         for fil in self.files:
             with open(join(self.BASETESTDIR, fil), "w") as sfile:
                 sfile.write("pass\n")
         for d in self.dirs:
             os.mkdir(join(self.BASETESTDIR, d))
 
         self.oldpath = os.getcwd()
         os.chdir(self.BASETESTDIR)
 
     def tearDown(self):
         os.chdir(self.oldpath)
         shutil.rmtree(self.BASETESTDIR)
 
     def test_1(self):
         """Test magic_run_completer, should match two alterntives
         """
         event = MockEvent(u"%run a")
         mockself = None
         match = set(magic_run_completer(mockself, event))
         self.assertEqual(match, {u"a.py", u"aao.py", u"adir/"})
 
     def test_2(self):
         """Test magic_run_completer, should match one alterntive
         """
         event = MockEvent(u"%run aa")
         mockself = None
         match = set(magic_run_completer(mockself, event))
         self.assertEqual(match, {u"aao.py"})
 
     def test_3(self):
         """Test magic_run_completer with unterminated " """
         event = MockEvent(u'%run "a')
         mockself = None
         match = set(magic_run_completer(mockself, event))
         self.assertEqual(match, {u"a.py", u"aao.py", u"adir/"})
 
     def test_completion_more_args(self):
         event = MockEvent(u'%run a.py ')
         match = set(magic_run_completer(None, event))
         self.assertEqual(match, set(self.files + self.dirs))
 
     def test_completion_in_dir(self):
         # Github issue #3459
         event = MockEvent(u'%run a.py {}'.format(join(self.BASETESTDIR, 'a')))
         print(repr(event.line))
         match = set(magic_run_completer(None, event))
         # We specifically use replace here rather than normpath, because
         # at one point there were duplicates 'adir' and 'adir/', and normpath
         # would hide the failure for that.
         self.assertEqual(match, {join(self.BASETESTDIR, f).replace('\\','/')
                             for f in (u'a.py', u'aao.py', u'aao.txt', u'adir/')})
 
 class Test_magic_run_completer_nonascii(unittest.TestCase):
     @onlyif_unicode_paths
     def setUp(self):
         self.BASETESTDIR = tempfile.mkdtemp()
         for fil in [u"aaø.py", u"a.py", u"b.py"]:
             with open(join(self.BASETESTDIR, fil), "w") as sfile:
                 sfile.write("pass\n")
         self.oldpath = os.getcwd()
         os.chdir(self.BASETESTDIR)
 
     def tearDown(self):
         os.chdir(self.oldpath)
         shutil.rmtree(self.BASETESTDIR)
 
     @onlyif_unicode_paths
     def test_1(self):
         """Test magic_run_completer, should match two alterntives
         """
         event = MockEvent(u"%run a")
         mockself = None
         match = set(magic_run_completer(mockself, event))
         self.assertEqual(match, {u"a.py", u"aaø.py"})
 
     @onlyif_unicode_paths
     def test_2(self):
         """Test magic_run_completer, should match one alterntive
         """
         event = MockEvent(u"%run aa")
         mockself = None
         match = set(magic_run_completer(mockself, event))
         self.assertEqual(match, {u"aaø.py"})
 
     @onlyif_unicode_paths
     def test_3(self):
         """Test magic_run_completer with unterminated " """
         event = MockEvent(u'%run "a')
         mockself = None
         match = set(magic_run_completer(mockself, event))
         self.assertEqual(match, {u"a.py", u"aaø.py"})
 
 # module_completer:
 
 def test_import_invalid_module():
     """Testing of issue https://github.com/ipython/ipython/issues/1107"""
     invalid_module_names = {'foo-bar', 'foo:bar', '10foo'}
     valid_module_names = {'foobar'}
     with TemporaryDirectory() as tmpdir:
         sys.path.insert( 0, tmpdir )
         for name in invalid_module_names | valid_module_names:
             filename = os.path.join(tmpdir, name + '.py')
             open(filename, 'w').close()
 
         s = set( module_completion('import foo') )
         intersection = s.intersection(invalid_module_names)
         nt.assert_equal(intersection, set())
 
         assert valid_module_names.issubset(s), valid_module_names.intersection(s)
 
 
 def test_bad_module_all():
     """Test module with invalid __all__
 
     https://github.com/ipython/ipython/issues/9678
     """
     testsdir = os.path.dirname(__file__)
     sys.path.insert(0, testsdir)
     try:
         results = module_completion('from bad_all import ')
         nt.assert_in('puppies', results)
         for r in results:
             nt.assert_is_instance(r, str)
     finally:
         sys.path.remove(testsdir)
+
+
+def test_module_without_init():
+    """
+    Test module without __init__.py.
+    
+    https://github.com/ipython/ipython/issues/11226
+    """
+    fake_module_name = "foo"
+    with TemporaryDirectory() as tmpdir:
+        sys.path.insert(0, tmpdir)
+        os.makedirs(os.path.join(tmpdir, fake_module_name))
+        s = try_import(mod=fake_module_name)
+        assert s == []