Sort and unique %config results

IPython/core/magics/config.py

@@ -108,8 +108,9 b' class ConfigMagics(Magics):'
         # some IPython objects are Configurable, but do not yet have
         # any configurable traits.  Exclude them from the effects of
         # this magic, as their presence is just noise:
-        configurables = [ c for c in self.shell.configurables
-                          if c.__class__.class_traits(config=True) ]
+        configurables = sorted(set([ c for c in self.shell.configurables
+                                     if c.__class__.class_traits(config=True)
+                                     ]), key=lambda x: x.__class__.__name__)
         classnames = [ c.__class__.__name__ for c in configurables ]
 
         line = s.strip()

IPython/core/tests/test_magic.py

@@ -80,6 +80,24 b' def test_config():'
     ## should not raise.
     _ip.magic('config')
 
+def test_config_available_configs():
+    """ test that config magic prints available configs in unique and
+    sorted order. """
+    with capture_output() as captured:
+        _ip.magic('config')
+
+    stdout = captured.stdout
+    config_classes = stdout.strip().split('\n')[1:]
+    nt.assert_list_equal(config_classes, sorted(set(config_classes)))
+
+def test_config_print_class():
+    """ test that config with a classname prints the class's options. """
+    with capture_output() as captured:
+        _ip.magic('config TerminalInteractiveShell')
+
+    stdout = captured.stdout
+    nt.assert_in("TerminalInteractiveShell options", stdout)
+
 def test_rehashx():
     # clear up everything
     _ip.alias_manager.clear_aliases()