Fix list of unions for graphql_fields (#41)

Author: denisart

graphql_query/base_model.py

@@ -38,7 +38,20 @@ def _get_fields(model: Type['GraphQLQueryBaseModel']) -> List[Union[str, Field,
             list_args = get_args(f.annotation)[0]
 
             _field_template.name = f_name
-            _field_template.fields = _get_fields(list_args)
+
+            if get_origin(list_args) is Union:
+                union_args = [union_arg for union_arg in get_args(list_args) if union_arg is not type(None)]
+
+                if len(union_args) == 1:
+                    _field_template.fields = _get_fields(union_args[0])
+
+                else:
+                    _field_template.fields = [
+                        InlineFragment(type=union_arg.__name__, fields=_get_fields(union_arg))
+                        for union_arg in union_args
+                    ]
+            else:
+                _field_template.fields = _get_fields(list_args)
 
         #
         # union type

tests/tests_base_model/test_inline_fragment.py

@@ -1,4 +1,4 @@
-from typing import Union
+from typing import Union, List
 
 from graphql_query import Field, GraphQLQueryBaseModel, InlineFragment
 
@@ -13,6 +13,7 @@ class Human(GraphQLQueryBaseModel):
     class Hero(GraphQLQueryBaseModel):
         name: str
         type: Union[Human, Droid]
+        types: List[Union[Human, Droid]]
 
     correct = [
         Field(name="name", fields=[]),
@@ -23,6 +24,13 @@ class Hero(GraphQLQueryBaseModel):
                 InlineFragment(type="Droid", fields=[Field(name="primaryFunction", fields=[])]),
             ],
         ),
+        Field(
+            name="types",
+            fields=[
+                InlineFragment(type="Human", fields=[Field(name="height", fields=[])]),
+                InlineFragment(type="Droid", fields=[Field(name="primaryFunction", fields=[])]),
+            ],
+        ),
     ]
     generated = Hero.graphql_fields()
 
@@ -39,5 +47,13 @@ class Hero(GraphQLQueryBaseModel):
       primaryFunction
     }
   }
+  types {
+    ... on Human {
+      height
+    }
+    ... on Droid {
+      primaryFunction
+    }
+  }
 }"""
     )