If you want to make a cli application with ruby i'd suggest thor or dry-cli as a gem(package in other languages). rake is ruby make... aka a build utility but

If you want to make a cli application with ruby i'd suggest thor or dry-cli as a gem(package in other languages). rake is ruby make... aka a build utility but it can and is used for a variety of things like testing and building and distribution. minitest is built in and is generally enough. rspec is the other big one and a lot of people like it but it's fairly complicated and it is better to stick to the basic one early on. as for debugging puts debugging is common(though a lot of things are caught at the testing phase since testing is big with ruby). if you are familiar with debuggers that is also an option with something like vscode or the command line but vscode is more usable(or the rubymine one that is a paid app).