Call prepare on lists of input objects

lib/graphql/schema/argument.rb

@@ -206,8 +206,8 @@ def statically_coercible?
       # Used by the runtime.
       # @api private
       def prepare_value(obj, value, context: nil)
-        if value.is_a?(GraphQL::Schema::InputObject)
-          value = value.prepare
+        if type.unwrap.kind.input_object?
+          value = recursively_prepare_input_object(value, type)
         end
 
         Schema::Validator.validate!(validators, obj, context, value)
@@ -373,6 +373,21 @@ def initialize(argument)
 
       private
 
+      def recursively_prepare_input_object(value, type)
+        if type.non_null?
+          type = type.of_type
+        end
+
+        if type.list? && !value.nil?
+          inner_type = type.of_type
+          value.map { |v| recursively_prepare_input_object(v, inner_type) }
+        elsif value.is_a?(GraphQL::Schema::InputObject)
+          value.prepare
+        else
+          value
+        end
+      end
+
       def validate_input_type(input_type)
         if input_type.is_a?(String) || input_type.is_a?(GraphQL::Schema::LateBoundType)
           # Do nothing; assume this will be validated later

spec/graphql/schema/input_object_spec.rb

@@ -420,13 +420,29 @@ def prepare_once(input:)
           input.prepared_count
         end
 
+        field :prepare_list, [Int] do
+          argument :input, [OnlyOnePrepareInputObject]
+        end
+
+        def prepare_list(input:)
+          input.map(&:prepared_count)
+        end
+
         field :prepare_and_load, String do
           argument :input, PrepareAndLoadInput
         end
 
         def prepare_and_load(input:)
           "#{input[:value]}/#{input[:thing][:name]}"
         end
+
+        field :prepare_list_of_lists, [[Int]] do
+          argument :input, [[OnlyOnePrepareInputObject]]
+        end
+
+        def prepare_list_of_lists(input:)
+          input.map { |i| i.map(&:prepared_count) }
+        end
       end
 
       class Schema < GraphQL::Schema
@@ -462,6 +478,14 @@ def self.object_from_id(id, _ctx)
       assert_equal 1, res["data"]["prepareOnce"]
     end
 
+    it "calls prepare on lists of input objects" do
+      res = InputObjectPrepareObjectTest::Schema.execute("{ prepareList( input:[{ i: 1 }, { i: 1}]) }")
+      assert_equal [1, 1], res["data"]["prepareList"]
+
+      res = InputObjectPrepareObjectTest::Schema.execute("{ prepareListOfLists( input:[[{ i: 1 }, { i: 1}], [{i: 2}, {i: 2}]]) }")
+      assert_equal [[1, 1], [1, 1]], res["data"]["prepareListOfLists"]
+    end
+
     it "calls prepare on the input object (variable)" do
       query_str = <<-GRAPHQL
       query ($input: RangeInput!){ inputs(input: $input) }