Port building Schema from introspection benchmark

From src/utilities/__tests__/buildClientSchema-benchmark.js

Author: ktosiek

tests/benchmarks/test_build_client_schema.py

@@ -0,0 +1,15 @@
+from graphql import build_client_schema, GraphQLSchema
+
+# noinspection PyUnresolvedReferences
+from ..fixtures import big_schema_introspection_result  # noqa: F401
+
+
+def test_building_ast_from_introspection(
+    benchmark, big_schema_introspection_result  # noqa: F811
+):
+    schema: GraphQLSchema = benchmark(
+        lambda: build_client_schema(
+            big_schema_introspection_result["data"], assume_valid=True
+        )
+    )
+    assert schema.query_type is not None

tests/fixtures/__init__.py

@@ -1,5 +1,5 @@
 """Fixtures for graphql tests"""
-
+import json
 from os.path import dirname, join
 
 from pytest import fixture  # type: ignore
@@ -12,6 +12,11 @@ def read_graphql(name):
     return open(path, encoding="utf-8").read()
 
 
+def read_json(name):
+    path = join(dirname(__file__), name + ".json")
+    return json.loads(open(path, encoding="utf-8").read())
+
+
 @fixture(scope="module")
 def kitchen_sink_query():
     return read_graphql("kitchen_sink")
@@ -25,3 +30,8 @@ def kitchen_sink_sdl():
 @fixture(scope="module")
 def big_schema_sdl():
     return read_graphql("github_schema")
+
+
+@fixture(scope="module")
+def big_schema_introspection_result():
+    return read_json("github_schema")