Add basic test for aiodataloader

Author: jkimbo

tests_asyncio/test_dataloader.py

@@ -0,0 +1,79 @@
+from collections import namedtuple
+from unittest.mock import Mock
+from pytest import mark
+from aiodataloader import DataLoader
+
+from graphene import ObjectType, String, Schema, Field, List
+
+
+CHARACTERS = {
+    "1": {"name": "Luke Skywalker", "sibling": "3"},
+    "2": {"name": "Darth Vader", "sibling": None},
+    "3": {"name": "Leia Organa", "sibling": "1"},
+}
+
+
+get_character = Mock(side_effect=lambda character_id: CHARACTERS[character_id])
+
+
+class CharacterType(ObjectType):
+    name = String()
+    sibling = Field(lambda: CharacterType)
+
+    async def resolve_sibling(character, info):
+        if character["sibling"]:
+            return await info.context.character_loader.load(character["sibling"])
+        return None
+
+
+class Query(ObjectType):
+    skywalker_family = List(CharacterType)
+
+    async def resolve_skywalker_family(_, info):
+        return await info.context.character_loader.load_many(["1", "2", "3"])
+
+
+mock_batch_load_fn = Mock(
+    side_effect=lambda character_ids: [get_character(id) for id in character_ids]
+)
+
+
+class CharacterLoader(DataLoader):
+    async def batch_load_fn(self, character_ids):
+        return mock_batch_load_fn(character_ids)
+
+
+Context = namedtuple("Context", "character_loader")
+
+
+@mark.asyncio
+async def test_basic_dataloader():
+    schema = Schema(query=Query)
+
+    character_loader = CharacterLoader()
+    context = Context(character_loader=character_loader)
+
+    query = """
+        {
+            skywalkerFamily {
+                name
+                sibling {
+                    name
+                }
+            }
+        }
+    """
+
+    result = await schema.execute_async(query, context=context)
+
+    assert not result.errors
+    assert result.data == {
+        "skywalkerFamily": [
+            {"name": "Luke Skywalker", "sibling": {"name": "Leia Organa"}},
+            {"name": "Darth Vader", "sibling": None},
+            {"name": "Leia Organa", "sibling": {"name": "Luke Skywalker"}},
+        ]
+    }
+
+    assert mock_batch_load_fn.call_count == 1
+    assert get_character.call_count == 3