I quite enjoy minisearch[1] which is also 0 dependencies, actively maintained, and I expect would work well in a worker environment. I dropped it into a service worker and plugged it with a simple point in polygon script to enable geosearch for a recent project[2] and it played v. nicely.

[1] https://github.com/lucaong/minisearch

[2] https://github.com/theprojectsomething/re.places