[ruby/irb] Support non-string input in show_source

(https://github.com/ruby/irb/pull/430)

* Support non-string input in show_source

* Test show_source as a method

1 files changed, 14 insertions, 0 deletions

diff --git a/lib/irb/extend-command.rb b/lib/irb/extend-command.rb
index 08a258fc53..acc23c9920 100644
--- a/lib/irb/extend-command.rb
+++ b/lib/irb/extend-command.rb
@@ -147,6 +147,20 @@ module IRB # :nodoc:
 
     ]
 
+    # Convert a command name to its implementation class if such command exists
+    def self.load_command(command)
+      command = command.to_sym
+      @EXTEND_COMMANDS.each do |cmd_name, cmd_class, load_file, *aliases|
+        next if cmd_name != command && aliases.all? { |alias_name, _| alias_name != command }
+
+        if !defined?(ExtendCommand) || !ExtendCommand.const_defined?(cmd_class, false)
+          require_relative load_file
+        end
+        return ExtendCommand.const_get(cmd_class, false)
+      end
+      nil
+    end
+
     # Installs the default irb commands:
     #
     # +irb_current_working_workspace+::   Context#main