src/librustc_data_structures/snapshot_map/test.rs

// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

use super::SnapshotMap;

#[test]
fn basic() {
    let mut map = SnapshotMap::new();
    map.insert(22, "twenty-two");
    let snapshot = map.snapshot();
    map.insert(22, "thirty-three");
    assert_eq!(map[&22], "thirty-three");
    map.insert(44, "fourty-four");
    assert_eq!(map[&44], "fourty-four");
    assert_eq!(map.get(&33), None);
    map.rollback_to(snapshot);
    assert_eq!(map[&22], "twenty-two");
    assert_eq!(map.get(&33), None);
    assert_eq!(map.get(&44), None);
}

#[test]
#[should_panic]
fn out_of_order() {
    let mut map = SnapshotMap::new();
    map.insert(22, "twenty-two");
    let snapshot1 = map.snapshot();
    let _snapshot2 = map.snapshot();
    map.rollback_to(snapshot1);
}

#[test]
fn nested_commit_then_rollback() {
    let mut map = SnapshotMap::new();
    map.insert(22, "twenty-two");
    let snapshot1 = map.snapshot();
    let snapshot2 = map.snapshot();
    map.insert(22, "thirty-three");
    map.commit(snapshot2);
    assert_eq!(map[&22], "thirty-three");
    map.rollback_to(snapshot1);
    assert_eq!(map[&22], "twenty-two");
}