Call rescue_from when skipping items

Author: amomchilov

lib/graphql/execution.rb

@@ -14,5 +14,12 @@ class Skip < GraphQL::Error; end
     # Just a singleton for implementing {Query::Context#skip}
     # @api private
     SKIP = Skip.new
+
+    # @api private
+    class SkipFromParentList < GraphQL::Error; end
+
+    # Just a singleton for implementing {Query::Context#skip}
+    # @api private
+    SKIP_FROM_PARENT_LIST = SkipFromParentList.new
   end
 end

lib/graphql/execution/interpreter/runtime.rb

@@ -523,14 +523,17 @@ def evaluate_selection_with_args(arguments, field_defn, next_path, ast_node, fie
               rescue GraphQL::ExecutionError => err
                 err
               rescue StandardError => err
-                if selection_result.has_graphql_graph_parent_that_skips_list_items_that_raise
-                  nil
-                else
-                  begin
+                begin
+                  if selection_result.has_graphql_graph_parent_that_skips_list_items_that_raise
+                    set_interpreter_context(:current_list_item_to_skip, nil) # Just set the key for now
+                    result = query.handle_or_reraise(err)
+                    delete_interpreter_context(:current_list_item_to_skip)
+                    result
+                  else
                     query.handle_or_reraise(err)
-                  rescue GraphQL::ExecutionError => ex_err
-                    ex_err
                   end
+                rescue GraphQL::ExecutionError => ex_err
+                  ex_err
                 end
               end
               after_lazy(app_result, owner: owner_type, field: field_defn, path: next_path, ast_node: ast_node, owner_object: object, arguments: resolved_arguments, result_name: result_name, result: selection_result) do |inner_result|
@@ -560,7 +563,7 @@ def dead_result?(selection_result)
 
         def set_result(selection_result, result_name, value)
           if !dead_result?(selection_result)
-            if value == GraphQL::Execution::SKIP
+            if value == GraphQL::Execution::SKIP_FROM_PARENT_LIST
               if selection_result.graphql_skip_list_items_that_raise
                 case selection_result
                 when GraphQLResultHash then selection_result.delete(result_name) # TODO: unify `#delete` interface with `#graphql_skip_at`
@@ -575,7 +578,7 @@ def set_result(selection_result, result_name, value)
                 if parent.nil? # This is a top-level result hash
                   @response = nil
                 else
-                  set_result(parent, name_in_parent, GraphQL::Execution::SKIP)
+                  set_result(parent, name_in_parent, GraphQL::Execution::SKIP_FROM_PARENT_LIST)
                   set_graphql_dead(selection_result)
                 end
               end
@@ -626,11 +629,7 @@ def set_graphql_dead(selection_result)
         def continue_value(path, value, parent_type, field, is_non_null, ast_node, result_name, selection_result) # rubocop:disable Metrics/ParameterLists
           case value
           when nil
-            if selection_result.has_graphql_graph_parent_that_skips_list_items_that_raise
-              # This writes the `nil` in, we need to patch it to skip instead.
-              print("skip!")
-              set_result(selection_result, result_name, GraphQL::Execution::SKIP)
-            elsif is_non_null
+            if is_non_null
               set_result(selection_result, result_name, nil) do
                 # This block is called if `result_name` is not dead. (Maybe a previous invalid nil caused it be marked dead.)
                 err = parent_type::InvalidNullError.new(parent_type, field, value)
@@ -686,6 +685,14 @@ def continue_value(path, value, parent_type, field, is_non_null, ast_node, resul
                 raise "Invariant: unexpected result class #{selection_result.class} (#{selection_result.inspect})"
               end
               HALT
+            elsif GraphQL::Execution::SKIP_FROM_PARENT_LIST == value
+              if selection_result.has_graphql_graph_parent_that_skips_list_items_that_raise
+                # This writes the `nil` in, we need to patch it to skip instead.
+                puts("skip!")
+                set_result(selection_result, result_name, GraphQL::Execution::SKIP_FROM_PARENT_LIST)
+              else
+                raise "Cannot skip list items from lists not marked `skip_items_on_raise: true`"
+              end
             else
               # What could this actually _be_? Anyhow,
               # preserve the default behavior of doing nothing with it.

lib/graphql/query/context.rb

@@ -11,6 +11,15 @@ def skip
           GraphQL::Execution::SKIP
         end
 
+        # Return this value to tell the runtime
+        # to exclude this whole object from parent list.
+        #
+        # The runtime will find the find the nearest parent list marked `skip_items_on_raise: true`,
+        # and exclude the entire list item (including this object).
+        def skip_from_parent_list
+          GraphQL::Execution::SKIP_FROM_PARENT_LIST
+        end
+
         # Add error at query-level.
         # @param error [GraphQL::ExecutionError] an execution error
         # @return [void]