fix interface inheritance syntax.

Author: gmac

graphql-stitching.gemspec

@@ -28,7 +28,7 @@ Gem::Specification.new do |spec|
 
   spec.add_runtime_dependency 'graphql', '>= 2.0'
 
-  spec.add_development_dependency 'bundler', '~> 2.0'
-  spec.add_development_dependency 'rake', '~> 12.0'
-  spec.add_development_dependency 'minitest', '~> 5.12'
+  spec.add_development_dependency 'bundler', '>= 2.0'
+  spec.add_development_dependency 'rake', '>= 12.0'
+  spec.add_development_dependency 'minitest', '>= 5.12'
 end

test/graphql/stitching/composer/merge_interface_test.rb

@@ -48,8 +48,8 @@ def test_merges_single_interface_memberships
   def test_merges_inherited_interface_memberships
     skip unless minimum_graphql_version?("2.0.3")
 
-    a = %{interface A { id:ID } interface AA implements A { id:ID } type C implements AA { id:ID } type Query { c:C }}
-    b = %{interface B { id:ID } interface BB implements B { id:ID } type C implements BB { id:ID } type Query { c:C }}
+    a = %{interface A { id:ID } interface AA implements A { id:ID } type C implements AA & A { id:ID } type Query { c:C }}
+    b = %{interface B { id:ID } interface BB implements B { id:ID } type C implements BB & B { id:ID } type Query { c:C }}
 
     supergraph = compose_definitions({ "a" => a, "b" => b })