Fix marking nodes as dirty when inserting into an existing hashmap entry (#4959)

* Fix marking nodes as dirty when inserting into an existing hashmap entry

* remove logs

Author: ealmloff

packages/stores/src/impls/btreemap.rs

@@ -131,7 +131,15 @@ impl<Lens: Readable<Target = BTreeMap<K, V>> + 'static, K: 'static, V: 'static>
         K: Ord,
         Lens: Writable,
     {
-        self.selector().mark_dirty_shallow();
+        // TODO: This method was released in 0.7 without the hash bound so we don't have a way
+        // to mark only the existing value as dirty. Instead we need to check if the value already exists
+        // in the map and mark the whole map as dirty if it does.
+        // In the 0.8 release, we should change this method to only mark the existing value as dirty.
+        if self.peek().contains_key(&key) {
+            self.selector().mark_dirty();
+        } else {
+            self.selector().mark_dirty_shallow();
+        }
         self.selector().write_untracked().insert(key, value);
     }
 

packages/stores/src/impls/hashmap.rs

@@ -139,7 +139,13 @@ impl<Lens: Readable<Target = HashMap<K, V, St>> + 'static, K: 'static, V: 'stati
         St: BuildHasher,
         Lens: Writable,
     {
+        // Mark the store itself as dirty since the keys may have changed
         self.selector().mark_dirty_shallow();
+        // Mark the existing value as dirty if it exists
+        self.selector()
+            .as_ref()
+            .hash_child_unmapped(key.borrow())
+            .mark_dirty();
         self.selector().write_untracked().insert(key, value);
     }
 

packages/stores/src/scope.rs

@@ -185,6 +185,15 @@ impl<Lens> SelectorScope<Lens> {
     {
         self.write.write_unchecked()
     }
+
+    /// Borrow the writer
+    pub(crate) fn as_ref(&self) -> SelectorScope<&Lens> {
+        SelectorScope {
+            path: self.path,
+            store: self.store,
+            write: &self.write,
+        }
+    }
 }
 
 impl<Lens: Readable> Readable for SelectorScope<Lens> {