cheat.sheets/sheets/_rust/tests

// Usually we place tests in a `tests` module. This module can be co-located in the file
// containing the module under test, or it can be located in a separate file
// (i.e. my_module.rs may have a child file, my_module/tests.rs, that contains a
// `tests` module)

// Tests are compiled only if the `test` cfg attribute is true (like when running `cargo test`)
#[cfg(test)]
mod tests {
    // The `test` attribute macro identifies functions that will run as tests
    #[test]
    fn basic_addition() {
        // `assert_eq` checks equality, and `assert` checks a boolean condition
        assert_eq!(1 + 1, 2);
        assert!(1 + 1 == 2);
        // There is also `assert_ne`, which checks for inequality
    }

    #[test]
    // The `should_panic` attribute macro identifies tests that should panic; therefore,
    // with this macro, a test that does not panic will fail
    #[should_panic]
    fn oh_no() {
        panic!("this is an expected failure!");
    }
}