Dicetest

Dicetest is a framework for writing tests with pseudorandom generated test data.

Status of this crate

The author does not consider this crate as stable yet.

Simple example

Here's an example of a broken sort function tested with Dicetest: ```rust fn bubble_sort(slice: &mut [T]) { let len = slice.len();

for _ in 0..len {
    for j in 1..len - 1 {
        let jpp = j + 1;
        if slice[j] > slice[jpp] {
            slice.swap(j, jpp);
        }
    }
}

}

[cfg(test)]

mod tests { use super::; use dicetest::prelude::tests::;

#[test]
fn result_of_bubble_sort_is_sorted() {
    dicetest!(|fate| {
        let mut v = dice::vec(dice::u8(..), ..).roll(fate);
        hint!("unsorted: {:?}", v);

        bubble_sort(&mut v);
        hint!("  sorted: {:?}", v);

        let is_sorted = v.windows(2).all(|w| w[0] <= w[1]);
        assert!(is_sorted);
    })
}

} ```

Running cargo test produces the following output: ```text The test failed after 36 passes.

Config

• seed: 795359663177100823
• start limit: 0
• end limit: 100
• passes: 1000

Counterexample

• run code: "ABIDje/+CYVkmmCVTwKJ2go6VrzZWMjO2Bqc9m3b3h0DAAAAAAAAAA=="
• limit: 3
• hints:
  • unsorted: [255, 252, 131]
  • sorted: [255, 131, 252]
• error: assertion failed: is_sorted ```

You can rerun the counterexample by setting a environment variable: text DICETEST_DEBUG=ABIDje/+CYVkmmCVTwKJ2go6VrzZWMjO2Bqc9m3b3h0DAAAAAAAAAA== cargo test

Alternatives

• Write down your test data and use a loop.
• Use the crate quickcheck.
• Use the crate proptest.

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.