Add pipeline lists to GraphQL

This adds Keyset pagination to GraphQL lists. PoC for that is
pipelines on merge requests and projects.

When paginating a list, the base-64 encoded id of the ordering
field (in most cases the primary key) can be passed in the `before` or
`after` GraphQL argument.

1 files changed, 16 insertions, 4 deletions

diff --git a/spec/support/helpers/graphql_helpers.rb b/spec/support/helpers/graphql_helpers.rb
index 0930b9da368..b9322975b5a 100644
--- a/spec/support/helpers/graphql_helpers.rb
+++ b/spec/support/helpers/graphql_helpers.rb
@@ -57,12 +57,12 @@ module GraphqlHelpers
 
     type.fields.map do |name, field|
       # We can't guess arguments, so skip fields that require them
-      next if field.arguments.any?
+      next if required_arguments?(field)
 
-      if scalar?(field)
-        name
-      else
+      if nested_fields?(field)
         "#{name} { #{all_graphql_fields_for(field_type(field))} }"
+      else
+        name
       end
     end.compact.join("\n")
   end
@@ -85,10 +85,22 @@ module GraphqlHelpers
     json_response['data']
   end
 
+  def nested_fields?(field)
+    !scalar?(field) && !enum?(field)
+  end
+
   def scalar?(field)
     field_type(field).kind.scalar?
   end
 
+  def enum?(field)
+    field_type(field).kind.enum?
+  end
+
+  def required_arguments?(field)
+    field.arguments.values.any? { |argument| argument.type.non_null? }
+  end
+
   def field_type(field)
     if field.type.respond_to?(:of_type)
       field.type.of_type