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 TypingInteraction#assert_source when the source passed to TypingInteraction.new(source, type, key) is not a KeyInput. TypingInteraction encodes keyDown/keyUp and is only valid on a key input source. Reached via KeyInput#create_key_down / create_key_up (which pass self) or by direct construction.

Source

Thrown at rb/lib/selenium/webdriver/common/interactions/typing_interaction.rb:39

  module WebDriver
    module Interactions
      #
      # Actions related to pressing keys.
      #
      # @api private
      #

      class TypingInteraction < Interaction
        attr_reader :type

        def initialize(source, type, key)
          super(source)
          @type = assert_type(type)
          @key = Keys.encode_key(key)
        end

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

        def assert_type(type)
          raise TypeError, "#{type.inspect} is not a valid key subtype" unless KeyInput::SUBTYPES.key? type

          KeyInput::SUBTYPES[type]
        end

        def encode
          {type: @type, value: @key}
        end
      end # TypingInteraction
    end # Interactions
  end # WebDriver
end # Selenium

View on GitHub (pinned to aa36b38e69)

Solutions

1. Use the public key DSL (driver.action.key_down('a').key_up('a').perform) which obtains a KeyInput internally.
2. If constructing TypingInteraction directly, ensure source.is_a?(Selenium::WebDriver::Interactions::KeyInput).

Example fix

# before
type_action = Selenium::WebDriver::Interactions::TypingInteraction.new(pointer, :down, 'a') # => TypeError

# after
key = Selenium::WebDriver::Interactions::KeyInput.new
key.create_key_down('a')

def key_input?(src)
  src.is_a?(Selenium::WebDriver::Interactions::KeyInput)
end

TypingInteraction.new(src, type, key) if key_input?(src)

When it happens

Trigger: Constructing Interactions::TypingInteraction.new(pointer, :down, 'a') or with a WheelInput/NoneInput source. Reached through the public key_down/key_up DSL only if the key input lookup is bypassed.

Common situations: Custom action-builder code that wires a key press onto a pointer or wheel device; refactors that swap device variables.

Related errors

• #{type.inspect} is not a valid key subtype
• #{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/9bd04121b8b1e3dd. Report an issue: GitHub.