thass0 / giveup

End-user geared termination on error

Giveup

giveup is a tiny abstraction for wrapping and nicely displaying Results to end-users.

It is meant to be used as a replacement for expect or unwrap_or_else, if an error occurred which terminates the program.

Example

// Here reading the config at the start of the cli app
// fails because the user has not yet created a config file.
let config_file = File::open("config-path")
    .hint("Create a configuration file")
    .example("touch config-filename")
    .giveup("Missing configuration file");

Motivation

In the above scenario expect is misplaced because we don't want the user of the CLI to be confronted with a panic.

To goal is to display an easily readable error message and offer as much help as possible, so the user can get back to what they originally intended to do (which never is fixing some issues of the tool one is using).

My usual solution would look somewhat like this:

let config = File::open("config-path").unwrap_or_else(|err| {
    eprintln!("Missing configuration file: {}\n\
        Create a new configuration file: `touch config-filename`",
        err);
    std::process::exit(1);
});

In this case the difference is not world-changing but using unwrap_or_else can get pretty verbose with lots of boilerplate repeating over and over again. Also, giveup is more friendly to dynamic error messages using variables.

Feedback

I primarily wrote giveup for my personal use, so I would love to get your feedback.