$foo = $foo gets completely compiled away

[Conduitry]

If you've mutated and autosubscription value without an assignment being involved, it will now be out of date with the actual store. Presumably, this is how we want this to behave, and something like $foo.push(whatever); shouldn't get instrumented.

Also presumably, the way to deal with this is to then do $foo = $foo; which will compile to foo.set($foo);, but currently that is getting compiled away into nothing.

[Conduitry]

I believe this is just a matter of:

diff --git a/src/compile/render-dom/index.ts b/src/compile/render-dom/index.ts
index ce2f3a00..0a0743b2 100644
--- a/src/compile/render-dom/index.ts
+++ b/src/compile/render-dom/index.ts
@@ -182,7 +182,7 @@ export default function dom(
 
 					if (node.operator === '=' && nodes_match(node.left, node.right)) {
 						const dirty = names.filter(name => {
-							return scope.find_owner(name) === component.instance_scope;
+							return name[0] === '$' || scope.find_owner(name) === component.instance_scope;
 						});
 
 						if (dirty.length) component.has_reactive_assignments = true;

Anything that begins with a $ should also be considered dirty, because even if it's an auto-subscription to some unknown global, we can still make it reactive.

[beenotung]

variable name starting with $ mush be a store, is that your case?

[Conduitry]

Variable names that begin with a $ are reserved in Svelte to always be auto-subscriptions to a store. You can't use variables beginning with a $ for anything else.