use super::quota::Quota;

#[test]
fn charge_within_limit_succeeds() {
    let mut q = Quota::new(4);
    assert!(q.charge(3));
    assert_eq!(q.used(), 3);
    assert!(q.charge(1));
    assert_eq!(q.used(), 4);
}

#[test]
fn charge_past_limit_fails_and_changes_nothing() {
    let mut q = Quota::new(4);
    q.charge(3);
    assert!(!q.charge(2));
    assert_eq!(q.used(), 3);
}

#[test]
fn uncharge_cannot_underflow() {
    let mut q = Quota::new(4);
    q.charge(1);
    assert!(!q.uncharge(2));
    assert_eq!(q.used(), 1);
    assert!(q.uncharge(1));
    assert_eq!(q.used(), 0);
}

#[test]
fn limit_can_be_raised_but_not_below_usage() {
    let mut q = Quota::new(4);
    q.charge(3);
    assert!(!q.set_limit(2));
    assert!(q.set_limit(10));
    assert!(q.charge(7));
}