How can I create parameterized tests in Rust?

Question

I want to write test cases that depend on parameters. My test case should be executed for each parameter and I want to see whether it succeeds or fails for each parameter.

Answer 1

The built-in test framework does not support this; the most common approach used is to generate a test for each case using macros, like this:

macro_rules! fib_tests {
    ($($name:ident: $value:expr,)*) => {
    $(
        #[test]
        fn $name() {
            let (input, expected) = $value;
            assert_eq!(expected, fib(input));
        }
    )*
    }
}

fib_tests! {
    fib_0: (0, 0),
    fib_1: (1, 1),
    fib_2: (2, 1),
    fib_3: (3, 2),
    fib_4: (4, 3),
    fib_5: (5, 5),
    fib_6: (6, 8),
}

This produces individual tests with names fib_0, fib_1, &c.