Macro fail 

macro_rules! fail {
    ($fmt:expr, $($arg:expr),*) => { ... };
    ($fmt:expr) => { ... };
}

A macro to create a failing ExtelResult.

If this macro is called the underlying error will be of type Error::TestFailed.

Example

use extel::{fail, ExtelResult, errors::Error};

fn always_fail() -> ExtelResult {
    let error_msg = "this is an error message!";
    fail!("This test fails with this error {}", error_msg)
}

match always_fail() {
    Ok(_) => panic!("test did not fail!"),
    Err(e) => {
        assert!(matches!(e, Error::TestFailed(_)));
        assert_eq!(
            "This test fails with this error this is an error message!",
            e.to_string()
        );
    }
}