Summary
In this chapter, we improved our CLI application, Bookmarkr, by adding better control for the input values for its command’s options (by explicitly indicating what options are required, setting default values where appropriate, designing validators to ensure the input values comply with the expected type, format, or range of values, and enabling auto-completion to make things simpler for the user).
We also added the ability to import and export application data from and to a file. This makes it easier to back up and restore data and even share it offline.
In the upcoming chapter, we will see how to implement a very important feature in every application: logging and error handling.
