ftracker_identifiers/cfi/
arbitrary.rs

1use arbitrary::{Arbitrary, Unstructured};
2
3use super::Cfi;
4use super::table::CATEGORIES;
5use super::validation::nth_letter;
6
7impl<'a> Arbitrary<'a> for Cfi {
8    fn arbitrary(u: &mut Unstructured<'a>) -> arbitrary::Result<Self> {
9        // Walk the embedded taxonomy so every generated value is valid by construction: a category,
10        // a group within it, and a permitted letter for each of the four attribute positions.
11        let category = &CATEGORIES[u.arbitrary::<u8>()? as usize % CATEGORIES.len()];
12        let group = &category.groups[u.arbitrary::<u8>()? as usize % category.groups.len()];
13
14        let mut bytes = [0u8; 6];
15        bytes[0] = category.code;
16        bytes[1] = group.code;
17        for (i, &mask) in group.attrs.iter().enumerate() {
18            let selector = u.arbitrary::<u8>()? as usize;
19            bytes[2 + i] = nth_letter(mask, selector);
20        }
21
22        Cfi::from_bytes(bytes).map_err(|_| arbitrary::Error::IncorrectFormat)
23    }
24}
25
26#[cfg(test)]
27mod tests {
28    use super::*;
29
30    #[test]
31    fn always_produces_valid_cfis() {
32        for seed in 0u32..256 {
33            let data = seed.to_le_bytes().repeat(8);
34            let mut u = Unstructured::new(&data);
35            let cfi = Cfi::arbitrary(&mut u).expect("arbitrary should always succeed");
36            // Re-validating via parse() proves the value round-trips through the exact same checks
37            // a hand-typed input would.
38            assert!(Cfi::parse(cfi.as_str()).is_ok());
39        }
40    }
41}
ftracker_identifiers/cfi/arbitrary.rs

ftracker_identifiers/cfi/
arbitrary.rs
