External type with interface

graphene_federation/service.py

@@ -26,9 +26,9 @@ def get_sdl(schema, custom_entities):
     string_schema = pattern.sub(" ", string_schema)
 
     for entity_name, entity in custom_entities.items():
-        type_def = "type %s " % entity_name
-        repl_str = "%s %s " % (type_def, entity._sdl)
-        pattern = re.compile(type_def)
+        type_def_re = r"(type %s[^\{]*)" % entity_name
+        repl_str = r"\1 %s " % entity._sdl
+        pattern = re.compile(type_def_re)
         string_schema = pattern.sub(repl_str, string_schema)
 
     for entity_name, entity in extended_types.items():

integration_tests/service_a/src/schema.py

@@ -1,4 +1,4 @@
-from graphene import ObjectType, String, Int, List, NonNull
+from graphene import ObjectType, String, Int, List, NonNull, Field
 from graphene_federation import build_schema, extend, external
 
 
@@ -7,10 +7,15 @@ class FileNode(ObjectType):
     id = external(Int(required=True))
 
 
+@extend(fields='id')
+class FunnyText(ObjectType):
+    id = external(Int(required=True))
+
+
 class Post(ObjectType):
     id = Int(required=True)
     title = String(required=True)
-    text = String(required=True)
+    text = Field(lambda: FunnyText)
     files = List(NonNull(FileNode))
 
 
@@ -20,9 +25,9 @@ class Query(ObjectType):
 
     def resolve_posts(root, info):
         return [
-            Post(id=1, title='title1', text='text1', files=[FileNode(id=1)]),
-            Post(id=2, title='title2', text='text2', files=[FileNode(id=2), FileNode(id=3)]),
-            Post(id=3, title='title3', text='text3'),
+            Post(id=1, title='title1', text=FunnyText(id=1), files=[FileNode(id=1)]),
+            Post(id=2, title='title2', text=FunnyText(id=2), files=[FileNode(id=2), FileNode(id=3)]),
+            Post(id=3, title='title3', text=FunnyText(id=3)),
         ]
 
     def resolve_goodbye(root, info):

integration_tests/service_b/src/schema.py

@@ -1,7 +1,21 @@
-from graphene import ObjectType, String, Int, Field
+from graphene import ObjectType, String, Int, Field, Interface
 from graphene_federation import build_schema, key
 
 
+class TextInterface(Interface):
+    id = Int(required=True)
+    body = String(required=True)
+
+
+@key(fields='id')
+class FunnyText(ObjectType):
+    class Meta:
+        interfaces = (TextInterface,)
+
+    def __resolve_reference(self, info, **kwargs):
+        return FunnyText(id=self.id, body=f'funny_text_{self.id}')
+
+
 @key(fields='id')
 class FileNode(ObjectType):
     id = Int(required=True)
@@ -13,8 +27,7 @@ def __resolve_reference(self, info, **kwargs):
 
 
 class Query(ObjectType):
-    # todo support query w/o root fields
     file = Field(lambda: FileNode)
 
 
-schema = build_schema(Query, types=[FileNode])
+schema = build_schema(Query, types=[FileNode, FunnyText])

integration_tests/tests/tests/test_main.py

@@ -26,7 +26,10 @@ def test_external_types():
             query {
                 posts {
                     title
-                    text
+                    text {
+                       id
+                       body
+                    }
                     files {
                        id
                        name
@@ -44,5 +47,8 @@ def test_external_types():
     posts = json.loads(response.content)['data']['posts']
     assert 3 == len(posts)
     assert [{"id": 1, "name": "file_1"}] == posts[0]['files']
+    assert {"id": 1, "body": "funny_text_1"} == posts[0]['text']
     assert [{"id": 2, "name": "file_2"}, {"id": 3, "name": "file_3"}] == posts[1]['files']
+    assert {"id": 2, "body": "funny_text_2"} == posts[1]['text']
     assert posts[2]['files'] is None
+    assert {"id": 3, "body": "funny_text_3"} == posts[2]['text']