Merge pull request #56 from Shopify/fix-mutation-execution-test

Prevent loader re-use after mutations

lib/graphql/batch/loader.rb

@@ -58,6 +58,7 @@ def resolve #:nodoc:
     # For Promise#sync
     def wait #:nodoc:
       if executor
+        executor.loaders.delete(loader_key)
         executor.resolve(self)
       else
         resolve

test/graphql_test.rb

@@ -342,6 +342,6 @@ def test_mutation_batch_subselection_execution
       }
     }
     assert_equal expected, result
-    assert_equal ["Product/1,2", "Product/3"], queries
+    assert_equal ["Product/1,2", "Product/2,3"], queries
   end
 end

test/support/loaders.rb

@@ -26,16 +26,12 @@ def perform(owners)
 end
 
 class CounterLoader < GraphQL::Batch::Loader
-  def initialize(hash)
-    @hash = hash
-  end
-
-  def load(key=Object.new)
-    super(key)
+  def cache_key(counter_array)
+    counter_array.object_id
   end
 
   def perform(keys)
-    keys.each { |key| fulfill(key, @hash[:counter][0]) }
+    keys.each { |counter_array| fulfill(counter_array, counter_array[0]) }
   end
 end
 

test/support/schema.rb

@@ -128,19 +128,21 @@
   end
 
   field :load_value, !types.Int do
-    resolve ->(_, _, ctx) { CounterLoader.for(ctx).load }
+    resolve ->(_, _, ctx) { CounterLoader.load(ctx[:counter]) }
   end
 end
 
 MutationType = GraphQL::ObjectType.define do
   name "Mutation"
 
   field :increment_counter, !CounterType do
-    resolve ->(_, _, ctx) { ctx[:counter][0] += 1; CounterLoader.for(ctx).load }
+    resolve ->(_, _, ctx) { ctx[:counter][0] += 1; CounterLoader.load(ctx[:counter]) }
   end
 
   field :counter_loader, !types.Int do
-    resolve ->(_, _, ctx) { CounterLoader.for(ctx).load }
+    resolve ->(_, _, ctx) {
+      CounterLoader.load(ctx[:counter])
+    }
   end
 
   field :no_op, !QueryType do