salsa/tests/singleton.rs
Niko Matsakis daaa78056a switch to new database design
Under this design, *all* databases are a
`DatabaseImpl<U>`, where the `U` implements
`UserData` (you can use `()` if there is none).

Code would default to `&dyn salsa::Database` but
if you want to give access to the userdata, you
can define a custom database trait
`MyDatabase: salsa::Databse` so long as you

* annotate `MyDatabase` trait definition of
  impls of `MyDatabase` with `#[salsa::db]`
* implement `MyDatabase` for `DatabaseImpl<U>`
  where `U` is your userdata (this could be a
  blanket impl, if you don't know the precise
  userdata type).

The `tests/common/mod.rs` shows the pattern.
2024-07-28 12:47:50 +00:00

49 lines
1.1 KiB
Rust

//! Basic Singleton struct test:
//!
//! Singleton structs are created only once. Subsequent `get`s and `new`s after creation return the same `Id`.
use expect_test::expect;
use salsa::Database as _;
use test_log::test;
#[salsa::input(singleton)]
struct MyInput {
field: u32,
id_field: u16,
}
#[test]
fn basic() {
let db = salsa::DatabaseImpl::new();
let input1 = MyInput::new(&db, 3, 4);
let input2 = MyInput::get(&db);
assert_eq!(input1, input2);
let input3 = MyInput::try_get(&db);
assert_eq!(Some(input1), input3);
}
#[test]
#[should_panic]
fn twice() {
let db = salsa::DatabaseImpl::new();
let input1 = MyInput::new(&db, 3, 4);
let input2 = MyInput::get(&db);
assert_eq!(input1, input2);
// should panic here
_ = MyInput::new(&db, 3, 5);
}
#[test]
fn debug() {
salsa::DatabaseImpl::new().attach(|db| {
let input = MyInput::new(db, 3, 4);
let actual = format!("{:?}", input);
let expected = expect!["MyInput { [salsa id]: Id(0), field: 3, id_field: 4 }"];
expected.assert_eq(&actual);
});
}