fix sandboxed tests

reactive_graph/tests/cleanup.rs

@@ -0,0 +1,88 @@
+use reactive_graph::{
+    computed::Memo,
+    owner::{on_cleanup, Owner},
+    signal::{RwSignal, Trigger},
+    traits::{Dispose, GetUntracked, Track},
+};
+use std::sync::Arc;
+
+#[test]
+fn cleanup_on_dispose() {
+    let owner = Owner::new();
+    owner.set();
+
+    struct ExecuteOnDrop(Option<Box<dyn FnOnce() + Send + Sync>>);
+
+    impl ExecuteOnDrop {
+        fn new(f: impl FnOnce() + Send + Sync + 'static) -> Self {
+            Self(Some(Box::new(f)))
+        }
+    }
+    impl Drop for ExecuteOnDrop {
+        fn drop(&mut self) {
+            self.0.take().unwrap()();
+        }
+    }
+
+    let trigger = Trigger::new();
+
+    println!("STARTING");
+
+    let memo = Memo::new(move |_| {
+        trigger.track();
+
+        // An example of why you might want to do this is that
+        // when something goes out of reactive scope you want it to be cleaned up.
+        // The cleaning up might have side effects, and those side effects might cause
+        // re-renders where new `on_cleanup` are registered.
+        let on_drop = ExecuteOnDrop::new(|| {
+            on_cleanup(|| println!("Nested cleanup in progress."))
+        });
+
+        on_cleanup(move || {
+            println!("Cleanup in progress.");
+            drop(on_drop)
+        });
+    });
+    println!("Memo 1: {:?}", memo);
+    memo.get_untracked(); // First cleanup registered.
+
+    memo.dispose(); // Cleanup not run here.
+
+    println!("Cleanup should have been executed.");
+
+    let memo = Memo::new(move |_| {
+        // New cleanup registered. It'll panic here.
+        on_cleanup(move || println!("Test passed."));
+    });
+    println!("Memo 2: {:?}", memo);
+    println!("^ Note how the memos have the same key (different versions).");
+    memo.get_untracked(); // First cleanup registered.
+
+    println!("Test passed.");
+
+    memo.dispose();
+}
+
+#[test]
+fn leak_on_dispose() {
+    let owner = Owner::new();
+    owner.set();
+
+    let trigger = Trigger::new();
+
+    let value = Arc::new(());
+    let weak = Arc::downgrade(&value);
+
+    let memo = Memo::new(move |_| {
+        trigger.track();
+
+        RwSignal::new(value.clone());
+    });
+
+    memo.get_untracked();
+
+    memo.dispose();
+
+    assert!(weak.upgrade().is_none()); // Should have been dropped.
+}