Method: GraphQL::Language::Nodes::AbstractNode#replace_child

Defined in:
lib/graphql/language/nodes.rb

#replace_child(previous_child, new_child) ⇒ Object

Copy self, but modify the copy so that previous_child is replaced by new_child



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# File 'lib/graphql/language/nodes.rb', line 92

def replace_child(previous_child, new_child)
  # Figure out which list `previous_child` may be found in
  method_name = previous_child.children_method_name
  # Get the value from this (original) node
  prev_children = public_send(method_name)
  if prev_children.is_a?(Array)
    # Copy that list, and replace `previous_child` with `new_child`
    # in the list.
    new_children = prev_children.dup
    prev_idx = new_children.index(previous_child)
    new_children[prev_idx] = new_child
  else
    # Use the new value for the given attribute
    new_children = new_child
  end
  # Copy this node, but with the new child value
  copy_of_self = merge(method_name => new_children)
  # Return the copy:
  copy_of_self
end