fix: improvements "untracked read" warnings in untrack, SSR cases (#791)

leptos_reactive/src/diagnostics.rs

@@ -5,6 +5,7 @@ use cfg_if::cfg_if;
 // you create a signal/memo, and where you access it non-reactively.
 
 #[cfg(debug_assertions)]
+#[allow(dead_code)] // allowed for SSR
 #[derive(Copy, Clone)]
 pub(crate) struct AccessDiagnostics {
     pub defined_at: &'static std::panic::Location<'static>,
@@ -33,6 +34,7 @@ cfg_if! {
 }
 
 impl SpecialNonReactiveZone {
+    #[allow(dead_code)] // allowed for SSR
     pub(crate) fn is_inside() -> bool {
         #[cfg(debug_assertions)]
         {

leptos_reactive/src/scope.rs

@@ -5,7 +5,8 @@ use crate::{
     node::NodeId,
     runtime::{with_runtime, RuntimeId},
     suspense::StreamChunk,
-    PinnedFuture, ResourceId, StoredValueId, SuspenseContext,
+    PinnedFuture, ResourceId, SpecialNonReactiveZone, StoredValueId,
+    SuspenseContext,
 };
 use futures::stream::FuturesUnordered;
 use std::{
@@ -176,9 +177,11 @@ impl Scope {
     /// ```
     pub fn untrack<T>(&self, f: impl FnOnce() -> T) -> T {
         with_runtime(self.runtime, |runtime| {
+            SpecialNonReactiveZone::enter();
             let prev_observer = runtime.observer.take();
             let untracked_result = f();
             runtime.observer.set(prev_observer);
+            SpecialNonReactiveZone::exit();
             untracked_result
         })
         .expect(

leptos_reactive/src/signal.rs

@@ -771,6 +771,7 @@ where
 
     /// Applies the function to the current Signal, if it exists, and subscribes
     /// the running effect.
+    #[track_caller]
     pub(crate) fn try_with<U>(
         &self,
         f: impl FnOnce(&T) -> U,
@@ -1828,7 +1829,7 @@ impl NodeId {
                 sources.borrow_mut().insert(*self);
             }
         } else {
-            #[cfg(debug_assertions)]
+            #[cfg(all(debug_assertions, not(feature = "ssr")))]
             {
                 if !SpecialNonReactiveZone::is_inside() {
                     let AccessDiagnostics {