salsa/tests/tracked_with_struct_db.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

59 lines
1.5 KiB
Rust

//! Test that a setting a field on a `#[salsa::input]`
//! overwrites and returns the old value.
use salsa::{Database, DatabaseImpl};
use test_log::test;
#[salsa::input]
struct MyInput {
field: String,
}
#[salsa::tracked]
struct MyTracked<'db> {
data: MyInput,
next: MyList<'db>,
}
#[derive(PartialEq, Eq, Clone, Debug, salsa::Update)]
enum MyList<'db> {
None,
Next(MyTracked<'db>),
}
#[salsa::tracked]
fn create_tracked_list(db: &dyn Database, input: MyInput) -> MyTracked<'_> {
let t0 = MyTracked::new(db, input, MyList::None);
let t1 = MyTracked::new(db, input, MyList::Next(t0));
t1
}
#[test]
fn execute() {
DatabaseImpl::new().attach(|db| {
let input = MyInput::new(db, "foo".to_string());
let t0: MyTracked = create_tracked_list(db, input);
let t1 = create_tracked_list(db, input);
expect_test::expect![[r#"
MyTracked {
[salsa id]: Id(1),
data: MyInput {
[salsa id]: Id(0),
field: "foo",
},
next: Next(
MyTracked {
[salsa id]: Id(0),
data: MyInput {
[salsa id]: Id(0),
field: "foo",
},
next: None,
},
),
}
"#]]
.assert_debug_eq(&t0);
assert_eq!(t0, t1);
})
}