Test for getdoc() returning None.

IPython/core/tests/test_oinspect.py

@@ -1,152 +1,159 b''
 """Tests for the object inspection functionality.
 """
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2010-2011 The IPython Development Team.
 #
 #  Distributed under the terms of the BSD License.
 #
 #  The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 from __future__ import print_function
 
 # Stdlib imports
 
 # Third-party imports
 import nose.tools as nt
 
 # Our own imports
 from .. import oinspect
 from IPython.utils import py3compat
 
 #-----------------------------------------------------------------------------
 # Globals and constants
 #-----------------------------------------------------------------------------
 
 inspector = oinspect.Inspector()
 
 #-----------------------------------------------------------------------------
 # Local utilities
 #-----------------------------------------------------------------------------
 
 # A few generic objects we can then inspect in the tests below
 
 class Call(object):
     """This is the class docstring."""
 
     def __init__(self, x, y=1):
         """This is the constructor docstring."""
 
     def __call__(self, *a, **kw):
         """This is the call docstring."""
 
     def method(self, x, z=2):
         """Some method's docstring"""
 
 class OldStyle:
     """An old-style class for testing."""
     pass
 
 def f(x, y=2, *a, **kw):
     """A simple function."""
 
 def g(y, z=3, *a, **kw):
     pass  # no docstring
 
 
 def check_calltip(obj, name, call, docstring):
     """Generic check pattern all calltip tests will use"""
     info = inspector.info(obj, name)
     call_line, ds = oinspect.call_tip(info)
     nt.assert_equal(call_line, call)
     nt.assert_equal(ds, docstring)
 
 #-----------------------------------------------------------------------------
 # Tests
 #-----------------------------------------------------------------------------
 
 def test_calltip_class():
     check_calltip(Call, 'Call', 'Call(x, y=1)', Call.__init__.__doc__)
 
 
 def test_calltip_instance():
     c = Call(1)
     check_calltip(c, 'c', 'c(*a, **kw)', c.__call__.__doc__)
 
 
 def test_calltip_method():
     c = Call(1)
     check_calltip(c.method, 'c.method', 'c.method(x, z=2)', c.method.__doc__)
 
 
 def test_calltip_function():
     check_calltip(f, 'f', 'f(x, y=2, *a, **kw)', f.__doc__)
 
 
 def test_calltip_function2():
     check_calltip(g, 'g', 'g(y, z=3, *a, **kw)', '<no docstring>')
 
 
 def test_calltip_builtin():
     check_calltip(sum, 'sum', None, sum.__doc__)
 
 def test_info():
     "Check that Inspector.info fills out various fields as expected."
     i = inspector.info(Call, oname='Call')
     nt.assert_equal(i['type_name'], 'type')
     expted_class = str(type(type))  # <class 'type'> (Python 3) or <type 'type'>
     nt.assert_equal(i['base_class'], expted_class)
     nt.assert_equal(i['string_form'], "<class 'IPython.core.tests.test_oinspect.Call'>")
     fname = __file__
     if fname.endswith(".pyc"):
         fname = fname[:-1]
     # case-insensitive comparison needed on some filesystems
     # e.g. Windows:
     nt.assert_equal(i['file'].lower(), fname.lower())
     nt.assert_equal(i['definition'], 'Call(self, *a, **kw)\n')
     nt.assert_equal(i['docstring'], Call.__doc__)
     nt.assert_equal(i['source'], None)
     nt.assert_true(i['isclass'])
     nt.assert_equal(i['init_definition'], "Call(self, x, y=1)\n")
     nt.assert_equal(i['init_docstring'], Call.__init__.__doc__)
 
     i = inspector.info(Call, detail_level=1)
     nt.assert_not_equal(i['source'], None)
     nt.assert_equal(i['docstring'], None)
 
     c = Call(1)
     c.__doc__ = "Modified instance docstring"
     i = inspector.info(c)
     nt.assert_equal(i['type_name'], 'Call')
     nt.assert_equal(i['docstring'], "Modified instance docstring")
     nt.assert_equal(i['class_docstring'], Call.__doc__)
     nt.assert_equal(i['init_docstring'], Call.__init__.__doc__)
     nt.assert_equal(i['call_docstring'], c.__call__.__doc__)
 
     # Test old-style classes, which for example may not have an __init__ method.
     if not py3compat.PY3:
         i = inspector.info(OldStyle)
         nt.assert_equal(i['type_name'], 'classobj')
 
         i = inspector.info(OldStyle())
         nt.assert_equal(i['type_name'], 'instance')
         nt.assert_equal(i['docstring'], OldStyle.__doc__)
 
 def test_getdoc():
     class A(object):
         """standard docstring"""
         pass
     
     class B(object):
         """standard docstring"""
         def getdoc(self):
             return "custom docstring"
     
+    class C(object):
+        """standard docstring"""
+        def getdoc(self):
+            return None
+    
     a = A()
     b = B()
+    c = C()
     
     nt.assert_equal(oinspect.getdoc(a), "standard docstring")
     nt.assert_equal(oinspect.getdoc(b), "custom docstring")
+    nt.assert_equal(oinspect.getdoc(c), "standard docstring")