Support for multiple keys

README.md

@@ -13,7 +13,20 @@ Based on discussion: https://github.com/graphql-python/graphene/issues/953#issue
 
 Supports now:
 * sdl (_service fields)  # make possible to add schema in federation (as is)
-* @key decorator (entity support) # to perform Queries across service boundaries
+* `@key` decorator (entity support) # to perform Queries across service boundaries
+    *  You can use multiple `@key` per each ObjectType
+    ```python
+        @key('id')
+        @key('email')
+        class User(ObjectType):
+            id = Int(required=True)
+            email = String()
+
+            def __resolve_reference(self, info, **kwargs):
+                if self.id is not None:
+                    return User(id=self.id, email=f'name_{self.id}@gmail.com')
+                return User(id=123, email=self.email)              
+    ```
 * extend  # extend remote types
 * external  # mark field as external 
 

graphene_federation/main.py

@@ -23,6 +23,12 @@ def build_schema(query, mutation=None, **kwargs):
 def key(fields: str):
     def decorator(Type):
         register_entity(Type.__name__, Type)
-        setattr(Type, '_sdl', '@key(fields: "%s")' % fields)
+
+        existing = getattr(Type, "_sdl", "")
+
+        key_sdl = f'@key(fields: "{fields}")'
+        updated = f"{key_sdl} {existing}" if existing else key_sdl
+
+        setattr(Type, '_sdl', updated)
         return Type
     return decorator

integration_tests/docker-compose.yml

@@ -24,13 +24,22 @@ services:
       timeout: 10s
       retries: 10
 
+  service_c:
+    build: service_c/.
+    volumes:
+      - ./service_c/src:/project/src
+      - ../:/project/federation_deps
+    command: sh -c "pip install ./federation_deps && python ./src/app.py"
+    healthcheck:
+      test: ["CMD", "curl", "-XGET", "http://0.0.0.0:5000/graphql"]
+      interval: 1s
+      timeout: 10s
+      retries: 10
+
   federation:
     build: federation/.
     volumes:
       - ./federation/src:/project/src
-    depends_on:
-      - service_a
-      - service_b
     ports:
       - 3000:3000
     healthcheck:
@@ -43,6 +52,8 @@ services:
         condition: service_healthy
       service_b:
         condition: service_healthy
+      service_c:
+        condition: service_healthy
 
   proxy_dep:
     image: busybox

integration_tests/federation/src/index.ts

@@ -3,11 +3,13 @@ import {ApolloGateway} from '@apollo/gateway'
 
 const serviceA_url: string = 'http://service_a:5000/graphql';
 const serviceB_url: string = 'http://service_b:5000/graphql';
+const serviceC_url: string = 'http://service_c:5000/graphql';
 
 const gateway = new ApolloGateway({
     serviceList: [
         { name: 'service_a', url: serviceA_url },
         { name: 'service_b', url: serviceB_url },
+        { name: 'service_c', url: serviceC_url },
     ],
 });
 

integration_tests/service_a/src/schema.py

@@ -33,11 +33,17 @@ def resolve_color(self, info, **kwargs):
         return self.id + 2
 
 
+@extend(fields='email')
+class User(ObjectType):
+    email = external(String())
+
+
 class Post(ObjectType):
     id = Int(required=True)
     title = String(required=True)
     text = Field(lambda: FunnyText)
     files = List(NonNull(FileNode))
+    author = Field(lambda: User)
 
 
 class Query(ObjectType):
@@ -49,6 +55,7 @@ def resolve_posts(root, info):
             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)),
+            Post(id=4, title='title4', text=FunnyText(id=4), author=User(email="frank@frank.com")),
         ]
 
     def resolve_goodbye(root, info):

integration_tests/service_b/src/schema.py

@@ -26,16 +26,27 @@ def __resolve_reference(self, info, **kwargs):
         return FileNode(id=self.id, name=f'file_{self.id}')
 
 
+@key('id')
+@key('email')
+class User(ObjectType):
+    id = Int(required=True)
+    email = String()
+
+    def __resolve_reference(self, info, **kwargs):
+        if self.id is not None:
+            return User(id=self.id, email=f'name_{self.id}@gmail.com')
+
+        user_id = 1001 if self.email == "frank@frank.com" else hash(self.email) % 10000000
+
+        return User(id=user_id, email=self.email)
+
+
 # to test that @key applied only to FileNode, but not to FileNodeAnother
 class FileNodeAnother(ObjectType):
     id = Int(required=True)
     name = String(required=True)
 
 
-class Query(ObjectType):
-    file = Field(lambda: FileNode)
-
-
 class FunnyMutation(Mutation):
     result = String(required=True)
 
@@ -48,4 +59,15 @@ class Mutation(ObjectType):
     funny_mutation = FunnyMutation.Field()
 
 
-schema = build_schema(Query, Mutation, types=[FileNode, FunnyText, FileNodeAnother])
+class Query(ObjectType):
+    file = Field(lambda: FileNode)
+
+
+types = [
+    FileNode,
+    FunnyText,
+    FileNodeAnother,
+    User
+]
+
+schema = build_schema(Query, Mutation, types=types)

integration_tests/service_c/Dockerfile

@@ -0,0 +1,10 @@
+FROM python:3.6-alpine3.9
+
+WORKDIR project
+RUN apk add curl
+
+COPY ./requirements.txt ./
+RUN pip install -r requirements.txt
+
+EXPOSE 5000
+CMD [ "python", "./src/app.py"]

integration_tests/service_c/requirements.txt

@@ -0,0 +1,3 @@
+graphene==2.1.7
+flask==1.1.1
+flask_graphql==2.0.0

integration_tests/service_c/src/app.py

@@ -0,0 +1,12 @@
+from flask import Flask
+
+from flask_graphql import GraphQLView
+from schema import schema
+
+app = Flask(__name__)
+app.debug = True
+
+app.add_url_rule('/graphql', view_func=GraphQLView.as_view('graphql', schema=schema, graphiql=True))
+
+if __name__ == '__main__':
+    app.run(host='0.0.0.0')

integration_tests/service_c/src/schema.py

@@ -0,0 +1,25 @@
+from graphene import ObjectType, String, Int, List, NonNull, Field
+from graphene_federation import build_schema, extend, external
+
+
+@extend(fields='id')
+class User(ObjectType):
+    id = external(Int(required=True))
+
+
+class Article(ObjectType):
+    id = Int(required=True)
+    text = String(required=True)
+    author = Field(lambda: User)
+
+
+class Query(ObjectType):
+    articles = List(NonNull(lambda: Article))
+
+    def resolve_articles(self, info):
+        return [
+            Article(id=1, text='some text', author=User(id=5))
+        ]
+
+
+schema = build_schema(Query)

integration_tests/tests/tests/test_main.py

@@ -32,6 +32,18 @@ def test_external_types():
                        id
                        name
                     }
+                    author {
+                        id
+                        email
+                    }
+                }
+                articles {
+                    id
+                    text
+                    author {
+                        id
+                        email
+                    }
                 }
             }
         """,
@@ -42,17 +54,24 @@ def test_external_types():
         json=query,
     )
     assert response.status_code == 200
-    posts = json.loads(response.content)['data']['posts']
-    assert 3 == len(posts)
+    data = json.loads(response.content)['data']
+    posts = data['posts']
+    articles = data['articles']
+
+    assert 4 == len(posts)
     assert [{'id': 1, 'name': 'file_1'}] == posts[0]['files']
     assert {'id': 1, 'body': 'funny_text_1', 'color': 3} == posts[0]['text']
     assert [{'id': 2, 'name': 'file_2'}, {'id': 3, 'name': 'file_3'}] == posts[1]['files']
     assert {'id': 2, 'body': 'funny_text_2', 'color': 4} == posts[1]['text']
     assert posts[2]['files'] is None
     assert {'id': 3, 'body': 'funny_text_3', 'color': 5} == posts[2]['text']
+    assert {'id': 1001, 'email': 'frank@frank.com', } == posts[3]['author']
 
+    assert articles == [
+        {'id': 1, 'text': 'some text', 'author': {'id': 5, 'email': 'name_5@gmail.com'}}]
 
-def test_key_decorator_applied_by_exact_match_only():
+
+def fetch_sdl():
     query = {
         'query': """
             query {
@@ -65,7 +84,11 @@ def test_key_decorator_applied_by_exact_match_only():
     }
     response = requests.post('http://service_b:5000/graphql', json=query)
     assert response.status_code == 200
-    sdl = response.json()['data']['_service']['sdl']
+    return response.json()['data']['_service']['sdl']
+
+
+def test_key_decorator_applied_by_exact_match_only():
+    sdl = fetch_sdl()
     assert 'type FileNode  @key(fields: "id")' in sdl
     assert 'type FileNodeAnother  @key(fields: "id")' not in sdl
 
@@ -86,3 +109,7 @@ def test_mutation_is_accessible_in_federation():
     assert 'errors' not in response.json()
     assert response.json()['data']['funnyMutation']['result'] == 'Funny'
 
+
+def test_multiple_key_decorators_apply_multiple_key_annotations():
+    sdl = fetch_sdl()
+    assert 'type User  @key(fields: "id") @key(fields: "email")' in sdl