Add tracing to sycamore-reactive and sycamore crates

packages/sycamore-reactive/Cargo.toml

@@ -17,7 +17,10 @@ paste = "1.0.12"
 serde = { version = "1.0.188", optional = true }
 slotmap = "1.0.6"
 smallvec = { version = "1.11.1", features = ["union"] }
+tracing = { version = "0.1.37", optional = true }
 
 [features]
 default = []
 nightly = []
+serde = ["dep:serde"]
+trace = ["dep:tracing"]

packages/sycamore-reactive/src/effects.rs

@@ -26,6 +26,7 @@ use crate::{create_memo, Root};
 /// `create_effect` should only be used for creating **side-effects**. It is generally not
 /// recommended to update signal states inside an effect. You probably should be using a
 /// [`create_memo`](crate::create_memo) instead.
+#[cfg_attr(debug_assertions, track_caller)]
 pub fn create_effect(f: impl FnMut() + 'static) {
     let f = Rc::new(RefCell::new(f));
     create_memo(move || {

packages/sycamore-reactive/src/node.rs

@@ -36,6 +36,9 @@ pub(crate) struct ReactiveNode {
     pub state: NodeState,
     /// Used for DFS traversal of the reactive graph.
     pub mark: Mark,
+    /// Keep track of where the signal was created for diagnostics.
+    #[cfg(debug_assertions)]
+    pub created_at: &'static std::panic::Location<'static>,
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]

packages/sycamore-reactive/src/root.rs

@@ -117,6 +117,14 @@ impl Root {
     /// * `root` - The reactive root.
     /// * `id` - The id associated with the reactive node.
     /// `SignalId` inside the state itself.
+    #[cfg_attr(
+        all(feature = "trace", not(debug_assertions)),
+        tracing::instrument(skip(self))
+    )]
+    #[cfg_attr(
+        all(feature = "trace", debug_assertions),
+        tracing::instrument(skip(self), fields(created_at = self.nodes.borrow()[current].created_at.to_string()))
+    )]
     fn run_node_update(&'static self, current: NodeId) {
         debug_assert_eq!(
             self.nodes.borrow()[current].state,
@@ -197,6 +205,8 @@ impl Root {
 
         // Traverse reactive graph.
         Self::dfs(start_node, &mut self.nodes.borrow_mut(), rev_sorted);
+        #[cfg(feature = "trace")]
+        tracing::trace!("update len: {}", rev_sorted.len());
 
         self.mark_dependents_dirty(start_node);
 
@@ -220,6 +230,14 @@ impl Root {
     /// Call this if `start_node` has been updated manually. This will automatically update all
     /// signals that depend on `start_node`.
     #[cfg_attr(debug_assertions, track_caller)]
+    #[cfg_attr(
+        all(feature = "trace", not(debug_assertions)),
+        tracing::instrument(skip(self))
+    )]
+    #[cfg_attr(
+        all(feature = "trace", debug_assertions),
+        tracing::instrument(skip(self), fields(created_at = self.nodes.borrow()[start_node].created_at.to_string()))
+    )]
     pub fn propagate_updates(&'static self, start_node: NodeId) {
         // Set the global root.
         let prev = Root::set_global(Some(self));

packages/sycamore-reactive/src/signals.rs

@@ -39,6 +39,8 @@ pub struct ReadSignal<T: 'static> {
     pub(crate) id: NodeId,
     root: &'static Root,
     /// Keep track of where the signal was created for diagnostics.
+    /// This is also stored in the Node but we want to have access to this when accessing a
+    /// disposed node so we store it here as well.
     #[cfg(debug_assertions)]
     created_at: &'static std::panic::Location<'static>,
     _phantom: PhantomData<T>,
@@ -129,6 +131,8 @@ pub(crate) fn create_empty_signal<T>() -> Signal<T> {
         context: Vec::new(),
         state: NodeState::Clean,
         mark: Mark::None,
+        #[cfg(debug_assertions)]
+        created_at: std::panic::Location::caller(),
     });
     // Add the signal to the parent's `children` list.
     let current_node = root.current_node.get();

packages/sycamore/Cargo.toml

@@ -101,6 +101,7 @@ suspense = [
 	"sycamore-core/suspense",
 ]
 serde = ["sycamore-reactive/serde"]
+trace = ["sycamore-reactive/trace"]
 wasm-bindgen-interning = ["web", "wasm-bindgen/enable-interning"]
 web = ["wasm-bindgen", "web-sys", "js-sys", "sycamore-web"]