I feel weird that runes are being used in `.js` files without explicit imports. This means some `.js` files without runes can still be interpreted independently

I feel weird that runes are being used in `.js` files without explicit imports. This means some `.js` files without runes can still be interpreted independently without being compiled, but some `.js` files with using runes will not (how do I tell my editor to not warn about these runes while still being `.js/.ts` files?) . For components, using `.svelte` instead of something like `.jsx` allowed avoiding this kind of issue. What would be a good solution to this? Would explicit imports fix this issue?