fix: improved diagnostics about non-reactive signal access (#1277)

leptos_dom/src/components.rs

@@ -271,8 +271,9 @@ where
         let mut repr = ComponentRepr::new_with_id(name, id);
 
         // disposed automatically when the parent scope is disposed
-        let (child, _) = cx
-            .run_child_scope(|cx| cx.untrack(|| children_fn(cx).into_view(cx)));
+        let (child, _) = cx.run_child_scope(|cx| {
+            cx.untrack_with_diagnostics(|| children_fn(cx).into_view(cx))
+        });
 
         repr.children.push(child);
 

leptos_reactive/src/runtime.rs

@@ -479,11 +479,17 @@ impl RuntimeId {
         instrument(level = "trace", skip_all,)
     )]
     #[inline(always)]
-    pub(crate) fn untrack<T>(self, f: impl FnOnce() -> T) -> T {
+    pub(crate) fn untrack<T>(
+        self,
+        f: impl FnOnce() -> T,
+        diagnostics: bool,
+    ) -> T {
         with_runtime(self, |runtime| {
             let untracked_result;
 
-            SpecialNonReactiveZone::enter();
+            if !diagnostics {
+                SpecialNonReactiveZone::enter();
+            }
 
             let prev_observer =
                 SetObserverOnDrop(self, runtime.observer.take());
@@ -493,7 +499,9 @@ impl RuntimeId {
             runtime.observer.set(prev_observer.1);
             std::mem::forget(prev_observer); // avoid Drop
 
-            SpecialNonReactiveZone::exit();
+            if !diagnostics {
+                SpecialNonReactiveZone::exit();
+            }
 
             untracked_result
         })
@@ -758,7 +766,7 @@ impl RuntimeId {
                 cur_deps_value.replace(Some(deps_value.clone()));
 
                 let callback_value =
-                    Some(self.untrack(wrapped_callback.clone()));
+                    Some(self.untrack(wrapped_callback.clone(), false));
 
                 prev_callback_value.replace(callback_value);
 

leptos_reactive/src/scope.rs

@@ -208,7 +208,14 @@ impl Scope {
     )]
     #[inline(always)]
     pub fn untrack<T>(&self, f: impl FnOnce() -> T) -> T {
-        self.runtime.untrack(f)
+        self.runtime.untrack(f, false)
+    }
+
+    #[doc(hidden)]
+    /// Suspends reactive tracking but keeps the diagnostic warnings for
+    /// untracked functions.
+    pub fn untrack_with_diagnostics<T>(&self, f: impl FnOnce() -> T) -> T {
+        self.runtime.untrack(f, true)
     }
 }
 

leptos_reactive/src/slice.rs

@@ -68,6 +68,7 @@ use crate::{
 /// // setting name only causes name to log, not count
 /// set_name.set("Bob".into());
 /// ```
+#[track_caller]
 pub fn create_slice<T, O, S>(
     cx: Scope,
     signal: RwSignal<T>,
@@ -85,6 +86,7 @@ where
 
 /// Takes a memoized, read-only slice of a signal. This is equivalent to the
 /// read-only half of [`create_slice`].
+#[track_caller]
 pub fn create_read_slice<T, O>(
     cx: Scope,
     signal: RwSignal<T>,
@@ -98,6 +100,7 @@ where
 
 /// Creates a setter to access one slice of a signal. This is equivalent to the
 /// write-only half of [`create_slice`].
+#[track_caller]
 pub fn create_write_slice<T, O>(
     cx: Scope,
     signal: RwSignal<T>,