loro/crates/loro-internal/src/fuzz.rs

use std::{fmt::Debug, time::Instant};

pub fn minify_error<T, F, N>(site_num: u8, actions: Vec<T>, f: F, normalize: N)
where
    F: Fn(u8, &mut [T]),
    N: Fn(u8, &mut [T]) -> Vec<T>,
    T: Clone + Debug,
{
    std::panic::set_hook(Box::new(|_info| {
        // ignore panic output
        // println!("{:?}", _info);
    }));

    let f_ref: *const _ = &f;
    let f_ref: usize = f_ref as usize;
    #[allow(clippy::redundant_clone)]
    let mut actions_clone = actions.clone();
    let action_ref: usize = (&mut actions_clone) as *mut _ as usize;
    #[allow(clippy::blocks_in_conditions)]
    if std::panic::catch_unwind(|| {
        // SAFETY: test
        let f = unsafe { &*(f_ref as *const F) };
        // SAFETY: test
        let actions_ref = unsafe { &mut *(action_ref as *mut Vec<T>) };
        f(site_num, actions_ref);
    })
    .is_ok()
    {
        println!("No Error Found");
        return;
    }

    let mut minified = actions.clone();
    let mut candidates = Vec::new();
    for i in 0..actions.len() {
        let mut new = actions.clone();
        new.remove(i);
        candidates.push(new);
    }

    println!("Minifying...");
    let start = Instant::now();
    while let Some(candidate) = candidates.pop() {
        let f_ref: *const _ = &f;
        let f_ref: usize = f_ref as usize;
        let mut actions_clone = candidate.clone();
        let action_ref: usize = (&mut actions_clone) as *mut _ as usize;
        #[allow(clippy::blocks_in_conditions)]
        if std::panic::catch_unwind(|| {
            // SAFETY: test
            let f = unsafe { &*(f_ref as *const F) };
            // SAFETY: test
            let actions_ref = unsafe { &mut *(action_ref as *mut Vec<T>) };
            f(site_num, actions_ref);
        })
        .is_err()
        {
            for i in 0..candidate.len() {
                let mut new = candidate.clone();
                new.remove(i);
                candidates.push(new);
            }
            if candidate.len() < minified.len() {
                minified = candidate;
                println!("New min len={}", minified.len());
            }
            if candidates.len() > 40 {
                candidates.drain(0..30);
            }
        }
        if start.elapsed().as_secs() > 10 && minified.len() <= 4 {
            break;
        }
        if start.elapsed().as_secs() > 60 {
            break;
        }
    }

    let minified = normalize(site_num, &mut minified);
    println!(
        "Old Length {}, New Length {}",
        actions.len(),
        minified.len()
    );
    dbg!(&minified);
    if actions.len() > minified.len() {
        minify_error(site_num, minified, f, normalize);
    }
}