[ruby/irb] Add "show_cmds" command to list all commands'

descriptions
(https://github.com/ruby/irb/pull/463)

https://github.com/ruby/irb/commit/7e857655ac

1 files changed, 39 insertions, 0 deletions

diff --git a/lib/irb/cmd/show_cmds.rb b/lib/irb/cmd/show_cmds.rb
new file mode 100644
index 0000000000..acced27d48
--- /dev/null
+++ b/lib/irb/cmd/show_cmds.rb
@@ -0,0 +1,39 @@
+# frozen_string_literal: true
+
+require "stringio"
+require_relative "nop"
+
+module IRB
+  # :stopdoc:
+
+  module ExtendCommand
+    class ShowCmds < Nop
+      category "IRB"
+      description "List all available commands and their description."
+
+      def execute(*args)
+        commands_info = IRB::ExtendCommandBundle.all_commands_info
+        commands_grouped_by_categories = commands_info.group_by { |cmd| cmd[:category] }
+        longest_cmd_name_length = commands_info.map { |c| c[:display_name] }.max { |a, b| a.length <=> b.length }.length
+
+        output = StringIO.new
+
+        commands_grouped_by_categories.each do |category, cmds|
+          output.puts Color.colorize(category, [:BOLD])
+
+          cmds.each do |cmd|
+            output.puts "  #{cmd[:display_name].to_s.ljust(longest_cmd_name_length)}    #{cmd[:description]}"
+          end
+
+          output.puts
+        end
+
+        puts output.string
+
+        nil
+      end
+    end
+  end
+
+  # :startdoc:
+end