Demo YAML to JSON and JSON to YAML command line utility

In this demo I just wanted to show that developing CLIs in Rust is a breeze.

There are three versions of this demo stored in separate branches:

• main - lazy and short version without proper error handling
• with-error-handling - added the error handling
• with-custom-type - added a custom type ExistingPath to showcase that you can validate anything at CLI arguments parsing

Build

You will need Rust installed on your computer, and then run:

cargo build --release

Run

After the build, the executable file is usually located at target/release/clap-yaml-json-demo (or with .exe extension on Windows), so run it:

On Linux/MacOS:

./target/release/clap-yaml-json-demo

On Windows:

.\target\release\clap-yaml-json-demo.exe

You will be greeted with clap help message that is generated automatically from the code! All the CLI arguments are validated and once you get the Command type, you can trust that all the types are valid (e.g. if you expect a number, it will be a number, not a string that you will still need to parse).