salsa/tests/cycle_recovery_call_query.rs

//! It's possible to call a Salsa query from within a cycle recovery fn.

#[salsa::tracked]
fn fallback_value(_db: &dyn salsa::Database) -> u32 {
    10
}

#[salsa::tracked(cycle_fn=cycle_fn, cycle_initial=cycle_initial)]
fn query(db: &dyn salsa::Database) -> u32 {
    let val = query(db);
    if val < 5 {
        val + 1
    } else {
        val
    }
}

fn cycle_initial(_db: &dyn salsa::Database) -> u32 {
    0
}

fn cycle_fn(
    db: &dyn salsa::Database,
    _value: &u32,
    _count: u32,
) -> salsa::CycleRecoveryAction<u32> {
    salsa::CycleRecoveryAction::Fallback(fallback_value(db))
}

#[test_log::test]
fn the_test() {
    let db = salsa::DatabaseImpl::default();

    assert_eq!(query(&db), 10);
}