expand test case to cover underscores that are sunder, dunder, and general underscore

graphene_django/converter.py

@@ -36,10 +36,18 @@ def _is_dunder(name):
             name[-3:-2] != '_')
 
 
+def _is_sunder(name):
+    """Returns True if a _sunder_ name, False otherwise."""
+    return (len(name) > 2 and
+            name[0] == name[-1] == '_' and
+            name[1:2] != '_' and
+            name[-2:-1] != '_')
+
+
 def convert_choice_name(name):
     name = force_text(name).encode('utf8').decode('ascii', 'ignore')
     name = to_const(name)
-    if _is_dunder(name):
+    if _is_sunder(name) or _is_dunder(name):
         name = "A%s" % name
     try:
         assert_valid_name(name)

graphene_django/tests/test_converter.py

@@ -199,8 +199,10 @@ def test_field_with_choices_collision():
 def test_field_with_choices_underscore():
     field = models.CharField(
         choices=(
-            ("_amount__", "Amount"),
+            ("_amount_", "Amount"),
             ("__percentage__", "Percentage"),
+            ("_not_sunder__", "Not Single Underscore"),
+            ("__not_dunder", "Not Double Underscore"),
         ),
     )
 
@@ -211,12 +213,11 @@ def test_field_with_choices_underscore():
             app_label = "test"
 
     graphene_type = convert_django_field_with_choices(field)
-    assert len(graphene_type._meta.enum.__members__) == 2
+    assert len(graphene_type._meta.enum.__members__) == 4
-    assert graphene_type._meta.enum.__members__["_AMOUNT__"].value == "_amount__"
+    assert "A_AMOUNT_" in graphene_type._meta.enum.__members__
-    assert graphene_type._meta.enum.__members__["_AMOUNT__"].description == "Amount"
+    assert "A__PERCENTAGE__" in graphene_type._meta.enum.__members__
-    assert graphene_type._meta.enum.__members__["A__PERCENTAGE__"].value == "__percentage__"
+    assert "_NOT_SUNDER__" in graphene_type._meta.enum.__members__
-    assert graphene_type._meta.enum.__members__["A__PERCENTAGE__"].description == "Percentage"
+    assert "__NOT_DUNDER" in graphene_type._meta.enum.__members__
-
 
 def test_should_float_convert_float():
     assert_conversion(models.FloatField, graphene.Float)