class GraphQL::Query::Variables

def initialize(ctx, ast_variables, provided_variables)
  schema = ctx.schema
  @context = ctx
  @provided_variables = provided_variables
  @errors = []
  @storage = ast_variables.each_with_object({}) do |ast_variable, memo|
    # Find the right value for this variable:
    # - First, use the value provided at runtime
    # - Then, fall back to the default value from the query string
    # If it's still nil, raise an error if it's required.
    variable_type = schema.type_from_ast(ast_variable.type)
    if variable_type.nil?
      # Pass -- it will get handled by a validator
    else
      variable_name = ast_variable.name
      default_value = ast_variable.default_value
      provided_value = @provided_variables[variable_name]
      value_was_provided = @provided_variables.key?(variable_name)
      validation_result = variable_type.validate_input(provided_value, ctx)
      if !validation_result.valid?
        # This finds variables that were required but not provided
        @errors << GraphQL::Query::VariableValidationError.new(ast_variable, variable_type, provided_value, validation_result)
      elsif value_was_provided
        # Add the variable if a value was provided
        memo[variable_name] = variable_type.coerce_input(provided_value, ctx)
      elsif default_value
        # Add the variable if it wasn't provided but it has a default value (including `null`)
        memo[variable_name] = GraphQL::Query::LiteralInput.coerce(variable_type, default_value, self)
      end
    end
  end
end