feat: standardize ScopedFuture::new_untracked like untrack() and untrack_with_diagnostics() (#4269)

reactive_graph/src/actions/action.rs

@@ -1,6 +1,7 @@
 use crate::{
     computed::{ArcMemo, Memo, ScopedFuture},
     diagnostics::is_suppressing_resource_load,
+    graph::untrack,
     owner::{ArcStoredValue, ArenaItem, Owner},
     send_wrapper_ext::SendOption,
     signal::{ArcMappedSignal, ArcRwSignal, MappedSignal, RwSignal},
@@ -207,10 +208,9 @@ where
             version: Default::default(),
             dispatched: Default::default(),
             action_fn: Arc::new(move |input| {
-                Box::pin(
-                    owner
-                        .with(|| ScopedFuture::new_untracked(action_fn(input))),
-                )
+                Box::pin(owner.with(|| {
+                    ScopedFuture::new_untracked(untrack(|| action_fn(input)))
+                }))
             }),
             #[cfg(any(debug_assertions, leptos_debuginfo))]
             defined_at: Location::caller(),
@@ -385,10 +385,9 @@ where
             version: Default::default(),
             dispatched: Default::default(),
             action_fn: Arc::new(move |input| {
-                Box::pin(SendWrapper::new(
-                    owner
-                        .with(|| ScopedFuture::new_untracked(action_fn(input))),
-                ))
+                Box::pin(SendWrapper::new(owner.with(|| {
+                    ScopedFuture::new_untracked(untrack(|| action_fn(input)))
+                })))
             }),
             #[cfg(any(debug_assertions, leptos_debuginfo))]
             defined_at: Location::caller(),

reactive_graph/src/computed/async_derived/arc_async_derived.rs

@@ -521,9 +521,10 @@ impl<T: 'static> ArcAsyncDerived<T> {
     {
         let fun = move || {
             let fut = fun();
-            let fut = ScopedFuture::new_untracked(async move {
-                SendOption::new(Some(fut.await))
-            });
+            let fut =
+                ScopedFuture::new_untracked_with_diagnostics(async move {
+                    SendOption::new(Some(fut.await))
+                });
             #[cfg(feature = "sandboxed-arenas")]
             let fut = Sandboxed::new(fut);
             fut

reactive_graph/src/computed/async_derived/mod.rs

@@ -54,11 +54,55 @@ impl<Fut> ScopedFuture<Fut> {
             fut,
         }
     }
+
+    #[doc(hidden)]
+    #[track_caller]
+    pub fn new_untracked_with_diagnostics(
+        fut: Fut,
+    ) -> ScopedFutureUntrackedWithDiagnostics<Fut> {
+        let owner = Owner::current().unwrap_or_default();
+        ScopedFutureUntrackedWithDiagnostics {
+            owner,
+            observer: None,
+            fut,
+        }
+    }
 }
 
 impl<Fut: Future> Future for ScopedFuture<Fut> {
     type Output = Fut::Output;
 
+    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        let this = self.project();
+        this.owner.with(|| {
+            #[cfg(debug_assertions)]
+            let _maybe_guard = if this.observer.is_none() {
+                Some(crate::diagnostics::SpecialNonReactiveZone::enter())
+            } else {
+                None
+            };
+            this.observer.with_observer(|| this.fut.poll(cx))
+        })
+    }
+}
+
+pin_project! {
+    /// A [`Future`] wrapper that sets the [`Owner`] and [`Observer`] before polling the inner
+    /// `Future`, output of [`ScopedFuture::new_untracked_with_diagnostics`].
+    ///
+    /// In leptos 0.9 this will be replaced with `ScopedFuture` itself.
+    #[derive(Clone)]
+    pub struct ScopedFutureUntrackedWithDiagnostics<Fut> {
+        owner: Owner,
+        observer: Option<AnySubscriber>,
+        #[pin]
+        fut: Fut,
+    }
+}
+
+impl<Fut: Future> Future for ScopedFutureUntrackedWithDiagnostics<Fut> {
+    type Output = Fut::Output;
+
     fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
         let this = self.project();
         this.owner