instructure/canvas-lms · error · ArgumentError

setting_name must be a symbol or string

Error message

setting_name must be a symbol or string

What it means

ArgumentError raised by CanvasOperations::Settings#setting when setting_name is neither a Symbol nor a String. This strictness guarantees the settings_key namespace is built from a predictable, inspectable name.

Solutions

1. Convert the value: name.to_s or name.to_sym before calling setting
2. Verify the variable actually contains the setting's name, not a record or ID
3. Use a constant/enum of allowed setting names

Example fix

// before
setting(id, default: 5)
// after
setting(id.to_s, default: 5)

raise 'must be Symbol or String' unless name.is_a?(Symbol) || name.is_a?(String)

def valid_setting_name?(name)
  name.is_a?(Symbol) || name.is_a?(String)
end

rescue ArgumentError => e
  Rails.logger.error("Bad setting name: #{e.message}")
end

When it happens

Trigger: Passing an Integer, nil-like wrapper, or other object as setting_name, e.g. setting(42, default: ...), or a variable holding a non-string type.

Common situations: Interpolating numbers/IDs directly as setting names; reading the name from JSON where it parsed as a number; passing a configuration object instead of its key.

Understand the failure class

Background: "Must be a positive integer", "Invalid value", "Unsupported": the invalid-argument-value error family, when a library rejects the value you pass — this error's family across 35 libraries.

Related errors

• progress_tracking must be a boolean
• setting_name cannot be nil
• Unsupported type_cast `#
• all elements must be User objects
• Invalid mode: #

AI-assisted analysis of instructure/canvas-lms@1c9f0bb801 (2026-09-15). Data as JSON: /api/errors/65e642945679dc98. Report an issue: GitHub.

Appendix: source

Thrown at lib/canvas_operations/base_concerns/settings.rb:83

        Canvas::Reloader.reload

        settings_key = settings_key(name, cluster:)
        value = Setting.get(settings_key, default)
        log_message("Fetched setting #{settings_key} with value `#{value.inspect}` before type casting", level: :debug)

        value
      end

      def modify_setting_for(name, value, cluster:)
        was_success = Setting.set(settings_key(name, cluster:), value)
        log_message("Modified setting #{settings_key(name, cluster:)} to value `#{value.inspect}` successfully? #{was_success}")

        was_success
      end

      def setting(setting_name, default:, type_cast: :to_s)
        raise ArgumentError, "setting_name cannot be nil" if setting_name.nil?
        raise ArgumentError, "setting_name must be a symbol or string" unless setting_name.is_a?(Symbol) || setting_name.is_a?(String)

        validate_type_cast!(type_cast, setting_name)

        # Method to get the Setting value and apply type casting
        #
        # If no cluster is provided, the current shard's cluster.
        define_singleton_method(setting_name) do |cluster: nil|
          cluster ||= Shard.current.database_server.id

          raw_value = setting_for(setting_name, default:, cluster:)

          case type_cast
          when Symbol
            raw_value.public_send(type_cast)
          when Proc
            type_cast.call(raw_value)
          end
        end

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