Replace doc tests with trybuild tests that assert the compiler errors

Author: NiklasEi

crates/bevy_ecs/Cargo.toml

@@ -29,6 +29,7 @@ serde = "1"
 [dev-dependencies]
 parking_lot = "0.11"
 rand = "0.8"
+trybuild = "1.0"
 
 [[example]]
 name = "events"

crates/bevy_ecs/src/system/mod.rs

@@ -786,172 +786,3 @@ mod tests {
         }
     }
 }
-
-/// ```compile_fail E0499
-/// use bevy_ecs::prelude::*;
-/// #[derive(Component)]
-/// struct A(usize);
-/// fn system(mut query: Query<&mut A>, e: Res<Entity>) {
-///     let mut iter = query.iter_mut();
-///     let a = &mut *iter.next().unwrap();
-///
-///     let mut iter2 = query.iter_mut();
-///     let b = &mut *iter2.next().unwrap();
-///
-///     // this should fail to compile
-///     println!("{}", a.0);
-/// }
-/// ```
-#[allow(unused)]
-#[cfg(doctest)]
-fn system_query_iter_lifetime_safety_test() {}
-
-/// ```compile_fail E0499
-/// use bevy_ecs::prelude::*;
-/// #[derive(Component)]
-/// struct A(usize);
-/// fn system(mut query: Query<&mut A>, e: Res<Entity>) {
-///     let mut a1 = query.get_mut(*e).unwrap();
-///     let mut a2 = query.get_mut(*e).unwrap();
-///     // this should fail to compile
-///     println!("{} {}", a1.0, a2.0);
-/// }
-/// ```
-#[allow(unused)]
-#[cfg(doctest)]
-fn system_query_get_lifetime_safety_test() {}
-
-/// ```compile_fail E0499
-/// use bevy_ecs::prelude::*;
-/// #[derive(Component)]
-/// struct A(usize);
-/// fn query_set(mut queries: QuerySet<(QueryState<&mut A>, QueryState<&A>)>, e: Res<Entity>) {
-///     let mut q2 = queries.q0();
-///     let mut iter2 = q2.iter_mut();
-///     let mut b = iter2.next().unwrap();
-///
-///     let q1 = queries.q1();
-///     let mut iter = q1.iter();
-///     let a = &*iter.next().unwrap();
-///
-///     // this should fail to compile
-///     b.0 = a.0
-/// }
-/// ```
-#[allow(unused)]
-#[cfg(doctest)]
-fn system_query_set_iter_lifetime_safety_test() {}
-
-/// ```compile_fail E0499
-/// use bevy_ecs::prelude::*;
-/// #[derive(Component)]
-/// struct A(usize);
-/// fn query_set(mut queries: QuerySet<(QueryState<&mut A>, QueryState<&A>)>, e: Res<Entity>) {
-///     let q1 = queries.q1();
-///     let mut iter = q1.iter();
-///     let a = &*iter.next().unwrap();
-///
-///     let mut q2 = queries.q0();
-///     let mut iter2 = q2.iter_mut();
-///     let mut b = iter2.next().unwrap();
-///
-///     // this should fail to compile
-///     b.0 = a.0;
-/// }
-/// ```
-#[allow(unused)]
-#[cfg(doctest)]
-fn system_query_set_iter_flip_lifetime_safety_test() {}
-
-/// ```compile_fail E0499
-/// use bevy_ecs::prelude::*;
-/// #[derive(Component)]
-/// struct A(usize);
-/// fn query_set(mut queries: QuerySet<(QueryState<&mut A>, QueryState<&A>)>, e: Res<Entity>) {
-///     let mut q2 = queries.q0();
-///     let mut b = q2.get_mut(*e).unwrap();
-///
-///     let q1 = queries.q1();
-///     let a = q1.get(*e).unwrap();
-///
-///     // this should fail to compile
-///     b.0 = a.0
-/// }
-/// ```
-#[allow(unused)]
-#[cfg(doctest)]
-fn system_query_set_get_lifetime_safety_test() {}
-
-/// ```compile_fail E0499
-/// use bevy_ecs::prelude::*;
-/// #[derive(Component)]
-/// struct A(usize);
-/// fn query_set(mut queries: QuerySet<(QueryState<&mut A>, QueryState<&A>)>, e: Res<Entity>) {
-///     let q1 = queries.q1();
-///     let a = q1.get(*e).unwrap();
-///
-///     let mut q2 = queries.q0();
-///     let mut b = q2.get_mut(*e).unwrap();
-///     // this should fail to compile
-///     b.0 = a.0
-/// }
-/// ```
-#[allow(unused)]
-#[cfg(doctest)]
-fn system_query_set_get_flip_lifetime_safety_test() {}
-
-/// ```compile_fail E0502
-/// use bevy_ecs::prelude::*;
-/// use bevy_ecs::system::SystemState;
-/// #[derive(Component)]
-/// struct A(usize);
-/// #[derive(Component)]
-/// struct B(usize);
-/// struct State {
-///     state_r: SystemState<Query<'static, 'static, &'static A>>,
-///     state_w: SystemState<Query<'static, 'static, &'static mut A>>,
-/// }
-///
-/// impl State {
-///     fn get_component<'w>(&mut self, world: &'w mut World, entity: Entity) {
-///         let q1 = self.state_r.get(&world);
-///         let a1 = q1.get(entity).unwrap();
-///
-///         let mut q2 = self.state_w.get_mut(world);
-///         let a2 = q2.get_mut(entity).unwrap();
-///
-///         // this should fail to compile
-///         println!("{}", a1.0);
-///     }
-/// }
-/// ```
-#[allow(unused)]
-#[cfg(doctest)]
-fn system_state_get_lifetime_safety_test() {}
-
-/// ```compile_fail E0502
-/// use bevy_ecs::prelude::*;
-/// use bevy_ecs::system::SystemState;
-/// #[derive(Component)]
-/// struct A(usize);
-/// #[derive(Component)]
-/// struct B(usize);
-/// struct State {
-///     state_r: SystemState<Query<'static, 'static, &'static A>>,
-///     state_w: SystemState<Query<'static, 'static, &'static mut A>>,
-/// }
-///
-/// impl State {
-///     fn get_components<'w>(&mut self, world: &'w mut World) {
-///         let q1 = self.state_r.get(&world);
-///         let a1 = q1.iter().next().unwrap();
-///         let mut q2 = self.state_w.get_mut(world);
-///         let a2 = q2.iter_mut().next().unwrap();
-///         // this should fail to compile
-///         println!("{}", a1.0);
-///     }
-/// }
-/// ```
-#[allow(unused)]
-#[cfg(doctest)]
-fn system_state_iter_lifetime_safety_test() {}

crates/bevy_ecs/tests/ui.rs

@@ -0,0 +1,5 @@
+#[test]
+fn test() {
+    let t = trybuild::TestCases::new();
+    t.compile_fail("tests/ui/*.rs");
+}

crates/bevy_ecs/tests/ui/system_query_get_lifetime_safety.rs

@@ -0,0 +1,13 @@
+use bevy_ecs::prelude::*;
+
+#[derive(Component)]
+struct A(usize);
+
+fn system(mut query: Query<&mut A>, e: Res<Entity>) {
+    let a1 = query.get_mut(*e).unwrap();
+    let a2 = query.get_mut(*e).unwrap();
+    // this should fail to compile
+    println!("{} {}", a1.0, a2.0);
+}
+
+fn main() {}

crates/bevy_ecs/tests/ui/system_query_get_lifetime_safety.stderr

@@ -0,0 +1,10 @@
+error[E0499]: cannot borrow `query` as mutable more than once at a time
+  --> tests/ui/system_query_get_lifetime_safety.rs:8:14
+   |
+7  |     let a1 = query.get_mut(*e).unwrap();
+   |              ----------------- first mutable borrow occurs here
+8  |     let a2 = query.get_mut(*e).unwrap();
+   |              ^^^^^^^^^^^^^^^^^ second mutable borrow occurs here
+9  |     // this should fail to compile
+10 |     println!("{} {}", a1.0, a2.0);
+   |                       -- first borrow later used here

crates/bevy_ecs/tests/ui/system_query_iter_lifetime_safety.rs

@@ -0,0 +1,17 @@
+use bevy_ecs::prelude::*;
+
+#[derive(Component)]
+struct A(usize);
+
+fn system(mut query: Query<&mut A>) {
+    let mut iter = query.iter_mut();
+    let a = &mut *iter.next().unwrap();
+
+    let mut iter2 = query.iter_mut();
+    let _ = &mut *iter2.next().unwrap();
+
+    // this should fail to compile
+    println!("{}", a.0);
+}
+
+fn main() {}

crates/bevy_ecs/tests/ui/system_query_iter_lifetime_safety.stderr

@@ -0,0 +1,11 @@
+error[E0499]: cannot borrow `query` as mutable more than once at a time
+  --> tests/ui/system_query_iter_lifetime_safety.rs:10:21
+   |
+7  |     let mut iter = query.iter_mut();
+   |                    ---------------- first mutable borrow occurs here
+...
+10 |     let mut iter2 = query.iter_mut();
+   |                     ^^^^^^^^^^^^^^^^ second mutable borrow occurs here
+...
+14 |     println!("{}", a.0);
+   |                    --- first borrow later used here

crates/bevy_ecs/tests/ui/system_query_set_get_lifetime_safety.rs

@@ -0,0 +1,28 @@
+use bevy_ecs::prelude::*;
+
+#[derive(Component)]
+struct A(usize);
+
+fn query_set(mut queries: QuerySet<(QueryState<&mut A>, QueryState<&A>)>, e: Res<Entity>) {
+    let mut q2 = queries.q0();
+    let mut b = q2.get_mut(*e).unwrap();
+
+    let q1 = queries.q1();
+    let a = q1.get(*e).unwrap();
+
+    // this should fail to compile
+    b.0 = a.0
+}
+
+fn query_set_flip(mut queries: QuerySet<(QueryState<&mut A>, QueryState<&A>)>, e: Res<Entity>) {
+    let q1 = queries.q1();
+    let a = q1.get(*e).unwrap();
+
+    let mut q2 = queries.q0();
+    let mut b = q2.get_mut(*e).unwrap();
+
+    // this should fail to compile
+    b.0 = a.0
+}
+
+fn main() {}

crates/bevy_ecs/tests/ui/system_query_set_get_lifetime_safety.stderr

@@ -0,0 +1,23 @@
+error[E0499]: cannot borrow `queries` as mutable more than once at a time
+  --> tests/ui/system_query_set_get_lifetime_safety.rs:10:14
+   |
+7  |     let mut q2 = queries.q0();
+   |                  ------------ first mutable borrow occurs here
+...
+10 |     let q1 = queries.q1();
+   |              ^^^^^^^^^^^^ second mutable borrow occurs here
+...
+14 |     b.0 = a.0
+   |     - first borrow later used here
+
+error[E0499]: cannot borrow `queries` as mutable more than once at a time
+  --> tests/ui/system_query_set_get_lifetime_safety.rs:21:18
+   |
+18 |     let q1 = queries.q1();
+   |              ------------ first mutable borrow occurs here
+...
+21 |     let mut q2 = queries.q0();
+   |                  ^^^^^^^^^^^^ second mutable borrow occurs here
+...
+25 |     b.0 = a.0
+   |           --- first borrow later used here

crates/bevy_ecs/tests/ui/system_query_set_iter_lifetime_safety.rs

@@ -0,0 +1,32 @@
+use bevy_ecs::prelude::*;
+
+#[derive(Component)]
+struct A(usize);
+
+fn query_set(mut queries: QuerySet<(QueryState<&mut A>, QueryState<&A>)>) {
+    let mut q2 = queries.q0();
+    let mut iter2 = q2.iter_mut();
+    let mut b = iter2.next().unwrap();
+
+    let q1 = queries.q1();
+    let mut iter = q1.iter();
+    let a = &*iter.next().unwrap();
+
+    // this should fail to compile
+    b.0 = a.0
+}
+
+fn query_set_flip(mut queries: QuerySet<(QueryState<&mut A>, QueryState<&A>)>) {
+    let q1 = queries.q1();
+    let mut iter = q1.iter();
+    let a = &*iter.next().unwrap();
+
+    let mut q2 = queries.q0();
+    let mut iter2 = q2.iter_mut();
+    let mut b = iter2.next().unwrap();
+
+    // this should fail to compile
+    b.0 = a.0;
+}
+
+fn main() {}

crates/bevy_ecs/tests/ui/system_query_set_iter_lifetime_safety.stderr

@@ -0,0 +1,23 @@
+error[E0499]: cannot borrow `queries` as mutable more than once at a time
+  --> tests/ui/system_query_set_iter_lifetime_safety.rs:11:14
+   |
+7  |     let mut q2 = queries.q0();
+   |                  ------------ first mutable borrow occurs here
+...
+11 |     let q1 = queries.q1();
+   |              ^^^^^^^^^^^^ second mutable borrow occurs here
+...
+16 |     b.0 = a.0
+   |     - first borrow later used here
+
+error[E0499]: cannot borrow `queries` as mutable more than once at a time
+  --> tests/ui/system_query_set_iter_lifetime_safety.rs:24:18
+   |
+20 |     let q1 = queries.q1();
+   |              ------------ first mutable borrow occurs here
+...
+24 |     let mut q2 = queries.q0();
+   |                  ^^^^^^^^^^^^ second mutable borrow occurs here
+...
+29 |     b.0 = a.0;
+   |           --- first borrow later used here

crates/bevy_ecs/tests/ui/system_state_get_lifetime_safety.rs

@@ -0,0 +1,28 @@
+use bevy_ecs::prelude::*;
+use bevy_ecs::system::SystemState;
+
+#[derive(Component)]
+struct A(usize);
+
+#[derive(Component)]
+struct B(usize);
+
+struct State {
+    state_r: SystemState<Query<'static, 'static, &'static A>>,
+    state_w: SystemState<Query<'static, 'static, &'static mut A>>,
+}
+
+impl State {
+    fn get_component(&mut self, world: &mut World, entity: Entity) {
+        let q1 = self.state_r.get(&world);
+        let a1 = q1.get(entity).unwrap();
+
+        let mut q2 = self.state_w.get_mut(world);
+        let _ = q2.get_mut(entity).unwrap();
+
+        // this should fail to compile
+        println!("{}", a1.0);
+    }
+}
+
+fn main() {}

crates/bevy_ecs/tests/ui/system_state_get_lifetime_safety.stderr

@@ -0,0 +1,11 @@
+error[E0502]: cannot borrow `*world` as mutable because it is also borrowed as immutable
+  --> tests/ui/system_state_get_lifetime_safety.rs:20:22
+   |
+17 |         let q1 = self.state_r.get(&world);
+   |                                   ------ immutable borrow occurs here
+...
+20 |         let mut q2 = self.state_w.get_mut(world);
+   |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^ mutable borrow occurs here
+...
+24 |         println!("{}", a1.0);
+   |                        ---- immutable borrow later used here