Rails 7 IRB console inserts escape key instead of execute delete command

Question

I am using Mac OS and since latest rails version the delete key does not work anymore.

❯ rails -v
Rails 7.0.4
❯ ruby -v
ruby 3.1.2p20 (2022-04-12 revision 4491bb740a) [arm64-darwin21]

When I hit delete instead of removing the char and the current cursor position it inserts ^[[3~.

I could not find out how to fix this. The previous rails version did not have this problem.

Answer 1

Ok, this is a bug in irb (or Reline rather) that is not yet fixed. Even though 2 PRs exist.

https://github.com/ruby/reline/issues/435

To monkeypatch add this snippet to your .irbrc

class Reline::ANSI

  def self.set_default_key_bindings(config)
    set_default_key_bindings_comprehensive_list(config)
    if Reline::Terminfo.enabled?
      set_default_key_bindings_terminfo(config)
    end
    {
      # extended entries of terminfo
      [27, 91, 49, 59, 53, 67] => :em_next_word, # Ctrl+→, extended entry
      [27, 91, 49, 59, 53, 68] => :ed_prev_word, # Ctrl+←, extended entry
      [27, 91, 49, 59, 51, 67] => :em_next_word, # Meta+→, extended entry
      [27, 91, 49, 59, 51, 68] => :ed_prev_word, # Meta+←, extended entry
    }.each_pair do |key, func|
      config.add_default_key_binding_by_keymap(:emacs, key, func)
      config.add_default_key_binding_by_keymap(:vi_insert, key, func)
      config.add_default_key_binding_by_keymap(:vi_command, key, func)
    end
    {
      [27, 91, 90] => :completion_journey_up, # S-Tab
    }.each_pair do |key, func|
      config.add_default_key_binding_by_keymap(:emacs, key, func)
      config.add_default_key_binding_by_keymap(:vi_insert, key, func)
    end
    {
      # default bindings
      [27, 32] => :em_set_mark,             # M-<space>
      [24, 24] => :em_exchange_mark,        # C-x C-x
    }.each_pair do |key, func|
      config.add_default_key_binding_by_keymap(:emacs, key, func)
    end
  end

end

Answer 2

It turns out that this helps:

nano ~/.irbrc
IRB.conf[:USE_READLINE] = true

But then, as a side effect the syntax highlight for the input line is turned off. I live with this as my delete key is more important.