> Test generation

> Data driven tests are an easy way to cover a lot of cases (granted, property testing is even better). The most trivial way of doing this is just looping over your cases

> […]

> You don't know which input was being processed on failure (without extra steps)

> Any debug output from prior iterations will flood the display when analyzing a failure

For generating separate tests for different inputs, keeping it easy to see which input failed the test I use the test-case crate

https://crates.io/crates/test-case

Here’s an example from the test-case readme:

    #[cfg(test)]
    mod tests {
        use test_case::test_case;

        #[test_case(-2, -4 ; "when both operands are negative")]
        #[test_case(2,  4  ; "when both operands are positive")]
        #[test_case(4,  2  ; "when operands are swapped")]
        fn multiplication_tests(x: i8, y: i8) {
            let actual = (x * y).abs();

            assert_eq!(8, actual)
        }
    }

And then when you run

    cargo test

You get this output:

    running 3 tests
    test tests::multiplication_tests::when_both_operands_are_negative ... ok
    test tests::multiplication_tests::when_both_operands_are_positive ... ok
    test tests::multiplication_tests::when_operands_are_swapped ... ok

    test result: ok. 3 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s