Merge pull request #4128 from rmosolgo/prepare-before-loads

Call prepare before loads for all arguments

lib/graphql/schema/argument.rb

@@ -259,26 +259,26 @@ def coerce_into_values(parent_object, values, context, argument_values)
         # If this isn't lazy, then the block returns eagerly and assigns the result here
         # If it _is_ lazy, then we write the lazy to the hash, then update it later
         argument_values[arg_key] = context.schema.after_lazy(coerced_value) do |resolved_coerced_value|
+          owner.validate_directive_argument(self, resolved_coerced_value)
+          prepared_value = begin
+            prepare_value(parent_object, resolved_coerced_value, context: context)
+          rescue StandardError => err
+            context.schema.handle_or_reraise(context, err)
+          end
+
           if loads && !from_resolver?
             loaded_value = begin
-              load_and_authorize_value(owner, coerced_value, context)
+              load_and_authorize_value(owner, prepared_value, context)
             rescue StandardError => err
               context.schema.handle_or_reraise(context, err)
             end
           end
 
-          maybe_loaded_value = loaded_value || resolved_coerced_value
+          maybe_loaded_value = loaded_value || prepared_value
           context.schema.after_lazy(maybe_loaded_value) do |resolved_loaded_value|
-            owner.validate_directive_argument(self, resolved_loaded_value)
-            prepared_value = begin
-              prepare_value(parent_object, resolved_loaded_value, context: context)
-            rescue StandardError => err
-              context.schema.handle_or_reraise(context, err)
-            end
-
             # TODO code smell to access such a deeply-nested constant in a distant module
             argument_values[arg_key] = GraphQL::Execution::Interpreter::ArgumentValue.new(
-              value: prepared_value,
+              value: resolved_loaded_value,
               definition: self,
               default_used: default_used,
             )

spec/graphql/schema/input_object_spec.rb

@@ -126,6 +126,24 @@ def prep(val)
         end
       end
 
+      class Thing < GraphQL::Schema::Object
+        field :name, String
+      end
+
+      class PreparedInputObj < GraphQL::Schema::InputObject
+        argument :thing_id, ID, loads: Thing, prepare: ->(val, ctx) { "thing-#{val}" }
+      end
+
+      class ResolverPrepares < GraphQL::Schema::Resolver
+        argument :input_object, PreparedInputObj
+        argument :thing_id, ID, loads: Thing, prepare: ->(val, ctx) { "thing-#{val}" }
+        type [String], null: false
+
+        def resolve(thing:, input_object:)
+          [thing.name, input_object[:thing].name]
+        end
+      end
+
       class Query < GraphQL::Schema::Object
         field :inputs, [String], null: false do
           argument :input, InputObj
@@ -134,6 +152,20 @@ class Query < GraphQL::Schema::Object
         def inputs(input:)
           [input.to_kwargs.inspect, input.instrument.name]
         end
+
+        field :multiple_prepares, [String] do
+          argument :input_object, PreparedInputObj
+          argument :thing_id, ID, loads: Thing, prepare: ->(val, ctx) { "thing-#{val}" }
+        end
+
+        def multiple_prepares(thing:, input_object:)
+          [thing.name, input_object[:thing].name]
+        end
+
+        field :resolver_prepares, resolver: ResolverPrepares
+
+
+        field :t, Thing
       end
 
       class Mutation < GraphQL::Schema::Object
@@ -193,7 +225,13 @@ class Schema < GraphQL::Schema
         lazy_resolve(Proc, :call)
 
         def self.object_from_id(id, ctx)
-          -> { Jazz::GloballyIdentifiableType.find(id) }
+          -> {
+            if id.start_with?("thing-")
+              OpenStruct.new(name: id)
+            else
+              Jazz::GloballyIdentifiableType.find(id)
+            end
+          }
         end
 
         def self.resolve_type(type, obj, ctx)
@@ -205,6 +243,14 @@ def self.resolve_type(type, obj, ctx)
       end
     end
 
+    it "always prepares before loading" do
+      res = InputObjectPrepareTest::Schema.execute("{ resolverPrepares(thingId: \"abc\", inputObject: { thingId: \"def\" }) }")
+      assert_equal ["thing-abc", "thing-def"], res["data"]["resolverPrepares"]
+
+      res = InputObjectPrepareTest::Schema.execute("{ multiplePrepares(thingId: \"abc\", inputObject: { thingId: \"def\" }) }")
+      assert_equal ["thing-abc", "thing-def"], res["data"]["multiplePrepares"]
+    end
+
     it "calls methods on the input object" do
       query_str = <<-GRAPHQL
       { inputs(input: { a: 1, b: 2, c: 3, d: 4, e: 5, instrumentId: "Instrument/Drum Kit" }) }