Add failing test, start to support args with Dataloader

Author: rmosolgo

lib/graphql.rb

@@ -128,6 +128,7 @@ def match?(pattern)
 require "graphql/filter"
 require "graphql/internal_representation"
 require "graphql/static_validation"
+require "graphql/dataloader"
 require "graphql/introspection"
 
 require "graphql/analysis_error"
@@ -148,7 +149,6 @@ def match?(pattern)
 require "graphql/unauthorized_error"
 require "graphql/unauthorized_field_error"
 require "graphql/load_application_object_failed_error"
-require "graphql/dataloader"
 require "graphql/deprecation"
 
 module GraphQL

lib/graphql/execution/interpreter/runtime.rb

@@ -198,6 +198,11 @@ def evaluate_selection(path, result_name, field_ast_nodes_or_ast_node, scoped_co
 
           begin
             kwarg_arguments = arguments(object, field_defn, ast_node)
+            # TODO: I think the thing to do here is, for each argument:
+            #  - enqueue a job to coerce _that_ argument and add it to the result set
+            #  - then check the result set: if it's complete, then call a method to continue execution
+            #  - I guess that'd be for each argument _definition_ -- maybe the counter would
+            #    be to check that each _definition_ has finished being loaded.
           rescue GraphQL::ExecutionError, GraphQL::UnauthorizedError => e
             continue_value(next_path, e, owner_type, field_defn, return_type.non_null?, ast_node)
             return

lib/graphql/query/null_context.rb

@@ -9,10 +9,11 @@ def visible_field?(t); true; end
         def visible_type?(t); true; end
       end
 
-      attr_reader :schema, :query, :warden
+      attr_reader :schema, :query, :warden, :dataloader
 
       def initialize
         @query = nil
+        @dataloader = GraphQL::Dataloader::NullDataloader.new
         @schema = GraphQL::Schema.new
         @warden = NullWarden.new(
           GraphQL::Filter.new,
@@ -36,7 +37,7 @@ def instance
           @instance = self.new
         end
 
-        def_delegators :instance, :query, :schema, :warden, :interpreter?
+        def_delegators :instance, :query, :schema, :warden, :interpreter?, :dataloader
       end
     end
   end

spec/graphql/dataloader_spec.rb

@@ -173,6 +173,16 @@ def common_ingredients(recipe_1_id:, recipe_2_id:)
         common_ids = recipe1[:ingredient_ids] & recipe2[:ingredient_ids]
         dataloader.with(DataObject).load_all(common_ids)
       end
+
+      field :common_ingredients_with_load, [Ingredient], null: false do
+        argument :recipe_1_id, ID, required: true, loads: Recipe
+        argument :recipe_2_id, ID, required: true, loads: Recipe
+      end
+
+      def common_ingredients_with_load(recipe_1:, recipe_2:)
+        common_ids = recipe_1[:ingredient_ids] & recipe_2[:ingredient_ids]
+        dataloader.with(DataObject).load_all(common_ids)
+      end
     end
 
     query(Query)
@@ -394,4 +404,34 @@ def database_log
     ]
     assert_equal expected_log, database_log
   end
+
+  it "loads arguments in batches" do
+    query_str = <<-GRAPHQL
+    {
+      commonIngredientsWithLoad(recipe1Id: 5, recipe2Id: 6) {
+        name
+      }
+    }
+    GRAPHQL
+
+    res = FiberSchema.execute(query_str)
+    expected_data = {
+      "commonIngredientsWithLoad" => [
+        {"name"=>"Corn"},
+        {"name"=>"Butter"},
+      ]
+    }
+    assert_equal expected_data, res["data"]
+
+    expected_log = [
+      [:mget, ["5", "6"]],
+      [:mget, ["2", "3"]],
+    ]
+    assert_equal expected_log, database_log
+  end
+
+
+  it "Works with analyzing arguments with `loads:`"
+
+  it "Works when `loads:` returns `request ...`"
 end