I am sure there are some applications that might need this due to obfuscation of data from the users... But doesn't the browser already have full text search? (Control-F)?
I haven't read through all of Lunr's docs and source, but based on my Solr/Elasticsearch experience, I'd expect to see (in time)…
Tokenization and (presumably) term normalization/analysis; a faster and smarter query language, for term order independence and boolean combinations of clauses; relevance scores and maybe even score boosting per field.
Better queryability really shouldn't be understated here. Just having term order independence focused on a specific set of JSON is going to be way better than naively matching any substring on the entire rendered page.
In the future I want to add even more powerful querying, restricting search to specific fields, taking into account the distance between terms, and adding faceted search to reduce the total documents being searched over.
One of the original goals of the project was specifically to provide a better alternative to just using the browsers built in find-in-page functionality
For example, the ability to search for a paragraph that contain two non-contiguous words would be very useful, but no browser (that I know of) is able to return elements that contain a set of tokens.
All browsers do is return exact matches from a string, with no concept of words.
It would be interesting to know if in this solution the index can be persisted to file or if it has to be rebuilt every time?