Fixed double underscore converter

Author: syrusakbary

graphene/contrib/django/filter/tests/test_fields.py

@@ -69,8 +69,8 @@ def assert_not_orderable(field):
 def test_filter_explicit_filterset_arguments():
     field = DjangoFilterConnectionField(ArticleNode, filterset_class=ArticleFilter)
     assert_arguments(field,
-                     'headline', 'headlineIcontains',
-                     'pubDate', 'pubDateGt', 'pubDateLt',
+                     'headline', 'headline_Icontains',
+                     'pubDate', 'pubDate_Gt', 'pubDate_Lt',
                      'reporter',
                      )
 
@@ -89,7 +89,7 @@ def test_filter_shortcut_filterset_arguments_dict():
         'reporter': ['exact'],
     })
     assert_arguments(field,
-                     'headline', 'headlineIcontains',
+                     'headline', 'headline_Icontains',
                      'reporter',
                      )
 

graphene/utils/str_converters.py

@@ -7,7 +7,7 @@ def to_camel_case(snake_str):
     components = snake_str.split('_')
     # We capitalize the first letter of each component except the first one
     # with the 'title' method and join them together.
-    return components[0] + "".join(x.title() for x in components[1:])
+    return components[0] + "".join(x.title() if x else '_' for x in components[1:])
 
 
 # From this response in Stackoverflow

graphene/utils/tests/test_str_converter.py

@@ -4,11 +4,14 @@
 def test_snake_case():
     assert to_snake_case('snakesOnAPlane') == 'snakes_on_a_plane'
     assert to_snake_case('SnakesOnAPlane') == 'snakes_on_a_plane'
+    assert to_snake_case('SnakesOnA_Plane') == 'snakes_on_a__plane'
     assert to_snake_case('snakes_on_a_plane') == 'snakes_on_a_plane'
+    assert to_snake_case('snakes_on_a__plane') == 'snakes_on_a__plane'
     assert to_snake_case('IPhoneHysteria') == 'i_phone_hysteria'
     assert to_snake_case('iPhoneHysteria') == 'i_phone_hysteria'
 
 
 def test_camel_case():
     assert to_camel_case('snakes_on_a_plane') == 'snakesOnAPlane'
+    assert to_camel_case('snakes_on_a__plane') == 'snakesOnA_Plane'
     assert to_camel_case('i_phone_hysteria') == 'iPhoneHysteria'