DataCollection.js (GitHub: thestorefront / DataCollection.js, License: MIT, npm: data-collection) from Storefront is a library for querying data. You can use it in browsers or Node. The example in the documentation uses an array of objects, then filters them based on key/values, and some sql-like operators including
The authors claim it's fast, and although I can't confirm this it does include a feature for defining indexes for specific keys. It's well documented and has 95.5% test coverage.
If you've got a project where you're logging errors with
console.error, but want to get more data like line numbers without modifying code, then you could try supererror (GitHub: nebulade/supererror, License: MIT, npm: supererror) by Johannes Zellner.
console.error to include colours, line number, and stacks for
Readability (GitHub: luin / node-readability, License: Apache 2.0, npm: node-readability) by Zihua Li turns pages into simplified Arc90-style HTML. It uses jsdom, supports more character encodings like GB2312, and converts relative URLs so images still work.
I seem to remember having issues with encodings and relative images with other Readability-derived projects, so this seems ideal.