Fix do not track nested reactivity in map_keyed/map_indexed (#742)

* Add unit tests

* Implement Trackable for MaybeDyn

* Make sure that we only track list in map_keyed/map_indexed

packages/sycamore-reactive/src/iter.rs

@@ -42,8 +42,9 @@ where
     let mut disposers_tmp: Vec<Option<NodeHandle>> = Vec::new();
 
     // Diff and update signal each time list is updated.
+    let _list = list.clone();
     let mut update = move || {
-        let new_items = list.get_clone();
+        let new_items = _list.get_clone();
         if new_items.is_empty() {
             // Fast path for removing all items.
             for dis in mem::take(&mut disposers) {
@@ -173,7 +174,7 @@ where
         mapped.clone()
     };
     let scope = use_current_scope();
-    create_memo(move || scope.run_in(&mut update))
+    create_memo(on(list, move || scope.run_in(&mut update)))
 }
 
 /// Function that maps a `Vec` to another `Vec` via a map function.
@@ -206,8 +207,9 @@ where
     let mut disposers: Vec<NodeHandle> = Vec::new();
 
     // Diff and update signal each time list is updated.
+    let _list = list.clone();
     let mut update = move || {
-        let new_items = list.get_clone();
+        let new_items = _list.get_clone();
 
         if new_items.is_empty() {
             // Fast path for removing all items.
@@ -263,7 +265,7 @@ where
         mapped.clone()
     };
     let scope = use_current_scope();
-    create_memo(move || scope.run_in(&mut update))
+    create_memo(on(list, move || scope.run_in(&mut update)))
 }
 
 #[cfg(test)]
@@ -517,4 +519,24 @@ mod tests {
             assert_eq!(counter.get(), 3);
         });
     }
+
+    /// Regression test for <https://github.com/sycamore-rs/sycamore/issues/739>
+    #[test]
+    fn issue_739_keyed_should_not_track_nested_signals() {
+        let _ = create_root(|| {
+            let items = create_signal(vec![create_signal(1), create_signal(2)]);
+            map_keyed(items, |x| on_cleanup(move || x.dispose()), |x| x.get());
+            items.set(items.get_clone()[1..].to_vec());
+        });
+    }
+
+    /// Regression test for <https://github.com/sycamore-rs/sycamore/issues/739>
+    #[test]
+    fn issue_739_indexed_should_not_track_nested_signals() {
+        let _ = create_root(|| {
+            let items = create_signal(vec![create_signal(()), create_signal(())]);
+            map_indexed(items, |x| on_cleanup(move || x.dispose()));
+            items.set(items.get_clone()[1..].to_vec());
+        });
+    }
 }

packages/sycamore-reactive/src/utils.rs

@@ -22,6 +22,16 @@ impl<T> Trackable for ReadSignal<T> {
     }
 }
 
+impl<T: Into<Self>> Trackable for MaybeDyn<T> {
+    fn _track(&self) {
+        match self {
+            MaybeDyn::Static(_) => {}
+            MaybeDyn::Signal(signal) => signal.track(),
+            MaybeDyn::Derived(f) => f()._track(),
+        }
+    }
+}
+
 macro_rules! impl_trackable_deps_for_tuple {
     ($($T:tt),*) => {
         paste::paste! {