SeleniumHQ/selenium · error · TypeError

#{source.type} is not a valid input type

Error message

#{source.type} is not a valid input type

What it means

Raised as TypeError by Pause#assert_source when the source passed into Pause.new(source, duration) is not an InputDevice (source.is_a? InputDevice is false). Pause is @api private; Pause is the most permissive interaction — it accepts any InputDevice (pointer, key, wheel, none).

Source

Thrown at rb/lib/selenium/webdriver/common/interactions/pause.rb:38

module Selenium
  module WebDriver
    module Interactions
      #
      # Action to create a waiting period between actions
      # Also used for synchronizing actions across devices
      #
      # @api private
      #

      class Pause < Interaction
        def initialize(source, duration = nil)
          super(source)
          @duration = duration
          @type = :pause
        end

        def assert_source(source)
          raise TypeError, "#{source.type} is not a valid input type" unless source.is_a? InputDevice
        end

        def encode
          output = {type: type}
          output[:duration] = (@duration * 1000).to_i if @duration
          output
        end
      end # Pause
    end # Interactions
  end # WebDriver
end # Selenium

View on GitHub (pinned to aa36b38e69)

Solutions

1. Pass a real InputDevice instance: device.create_pause(duration) rather than hand-constructing Pause with an arbitrary source.
2. Verify the device inherits Selenium::WebDriver::Interactions::InputDevice before constructing Pause.

Example fix

# before
pause = Selenium::WebDriver::Interactions::Pause.new(:pointer, 0.5) # => TypeError

# after
pointer = Selenium::WebDriver::Interactions::PointerInput.new(:mouse)
pause = Selenium::WebDriver::Interactions::Pause.new(pointer, 0.5)

def input_device?(src)
  src.is_a?(Selenium::WebDriver::Interactions::InputDevice)
end

# Pause accepts any InputDevice:
Pause.new(src, duration) if input_device?(src)

When it happens

Trigger: Constructing Interactions::Pause.new(source, duration) where source is not an InputDevice instance (e.g. a Symbol, a PointerInput subclass that does not extend InputDevice, or nil). Reachable via create_pause on an input device whose source was replaced.

Common situations: Custom interaction code that builds a Pause against the wrong object, or a subclassing mistake where a custom device forgets to inherit InputDevice.

Related errors

• #{source.type} is not a valid input type
• #{source.type} is not a valid input type
• #{source.type} is not a valid input type
• #{source.type} is not a valid input type
• #{source.type} is not a valid input type

AI-assisted analysis of SeleniumHQ/selenium@aa36b38e69 (2026-08-14). Data as JSON: /api/errors/e5c6b83ed8f0acca. Report an issue: GitHub.