fix templates being registered in mutations many times (#722)

packages/core/src/create.rs

@@ -81,9 +81,7 @@ impl<'b> VirtualDom {
 
         // The best renderers will have templates prehydrated and registered
         // Just in case, let's create the template using instructions anyways
-        if !self.templates.contains_key(&node.template.get().name) {
         self.register_template(node.template.get());
-        }
 
         // we know that this will generate at least one mutation per node
         self.mutations
@@ -389,10 +387,15 @@ impl<'b> VirtualDom {
 
     /// Insert a new template into the VirtualDom's template registry
     pub(crate) fn register_template(&mut self, mut template: Template<'static>) {
-        // First, make sure we mark the template as seen, regardless if we process it
         let (path, byte_index) = template.name.rsplit_once(':').unwrap();
         let byte_index = byte_index.parse::<usize>().unwrap();
-
+        // First, check if we've already seen this template
+        if self
+            .templates
+            .get(&path)
+            .filter(|set| set.contains_key(&byte_index))
+            .is_none()
+        {
             // if hot reloading is enabled, then we need to check for a template that has overriten this one
             #[cfg(debug_assertions)]
             if let Some(mut new_template) = self
@@ -415,6 +418,7 @@ impl<'b> VirtualDom {
                 self.mutations.templates.push(template);
             }
         }
+    }
 
     pub(crate) fn create_dynamic_node(
         &mut self,