Without a doubt, this is the stupidest and most frustrating bug I've ever created. Essentially, DOM nodes weren't being replaced or removed correctly because current was stuck on its origins in a DocumentFragment. It looked like some frustrating situation in which returns from appendChild were still referring back to the fragment, etc. No — I just literally wasn't ever using the return value, and instead was using the original value from the function call. Ridiculous, but so satisfying when it suddenly fixed a bunch of issues.

TODO.md

@@ -1,7 +1,5 @@
 - [ ] Async
   - [x] Resource
-    - [ ] Render bug: when doing e.g., a `match` and having multiple branches with separate `template`s, all exist as separate document fragment and replace the fragment, not one another -- find a way to make sure that `Child<'a>` returned from `insert` is _actually_ attached to the DOM
-    - [ ] Render bug with list reconciliation
   - [ ] Suspense
 - [ ] Docs (and clippy warning to insist on docs)
 - [ ] Read through + understand...

leptos_dom/src/render.rs

@@ -98,15 +98,12 @@ pub fn insert<'a>(
                     value = f();
                 }
 
-                insert_expression(
+                current = Some(insert_expression(
                     parent.clone().unchecked_into(),
                     &f(),
                     current.clone().unwrap_or(Child::Null),
-                    //current.get_untracked().clone(), // get untracked to avoid infinite loop when we set current, below
                     before.as_ref(),
-                );
-
-                current = Some(value);
+                ));
             });
         }
         _ => {
@@ -132,6 +129,12 @@ pub fn insert_expression<'a>(
         parent.node_name(),
         current
     );
+    if let Child::Node(node) = &current {
+        crate::log!(
+            "current's parent = {}",
+            node.parent_node().unwrap().node_name()
+        );
+    }
 
     if new_value == &current {
         current