clap/tests/app_from_crate.rs

use clap::{app_from_crate, ErrorKind};

static EVERYTHING: &str = "clap {{version}}
Kevin K. <kbknapp@gmail.com>:Clap Maintainers
A simple to use, efficient, and full-featured Command Line Argument Parser

USAGE:
    clap

FLAGS:
    -h, --help       Prints help information
    -V, --version    Prints version information
";

#[test]
fn app_from_crate() {
    let res = app_from_crate!().try_get_matches_from(vec!["clap", "--help"]);

    assert!(res.is_err());
    let err = res.unwrap_err();
    assert_eq!(err.kind, ErrorKind::HelpDisplayed);
    assert_eq!(
        err.message,
        EVERYTHING.replace("{{version}}", env!("CARGO_PKG_VERSION"))
    );
}