Add missing spec from rmosolgo#3326

Author: rmosolgo

spec/graphql/schema/field/connection_extension_spec.rb

@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+require "spec_helper"
+
+describe GraphQL::Schema::Field::ConnectionExtension do
+  class ConnectionShortcutSchema < GraphQL::Schema
+    class ShortcutResolveExtension < GraphQL::Schema::FieldExtension
+      def resolve(**rest)
+        ["a", "b", "c", "d", "e"]
+      end
+    end
+    class Query < GraphQL::Schema::Object
+      field :names, GraphQL::Types::String.connection_type, null: false, extensions: [ShortcutResolveExtension]
+      def names
+        raise "This should never be called"
+      end
+    end
+
+    query(Query)
+  end
+
+  it "implements connection handling even when resolve is shortcutted" do
+    res = ConnectionShortcutSchema.execute("{ names(first: 2) { nodes } }")
+    assert_equal ["a", "b"], res["data"]["names"]["nodes"]
+  end
+end