fuzzysearch.js

// context: https://twitter.com/codepo8/status/572863924887945216

function fuzzysearch(query, text) {
  // Build a regex, then test text against it:
  return RegExp(
    query
      // Escape any special regex characters:
      .replace(/[.*+?^${}()|[\]\/\\]/g, '\\$&')
      // Any escaped or non-escaped character can be followed by
      // any number of other characters (.*):
      .replace(/\\?./g, '$&.*')
  ).test(text);
}

fuzzysearch('twl', 'cartwheel') // <- true
fuzzysearch('cart', 'cartwheel') // <- true
fuzzysearch('cw', 'cartwheel') // <- true
fuzzysearch('ee', 'cartwheel') // <- true
fuzzysearch('art', 'cartwheel') // <- true
fuzzysearch('eeel', 'cartwheel') // <- false
fuzzysearch('dog', 'cartwheel') // <- false
fuzzysearch('[]', '[....]') // <- true

Neat, you could just do \W that matches all the characters that need escaping:

function fuzzysearch(query, text) {
// Build a regex, then test text against it:
return RegExp(
  query
    // Escape any special regex characters:
    .replace(/\W/g, '\\$&')
    // Any escaped or non-escaped character can be followed by
    // any number of other characters (.*):
    .replace(/\\?./g, '$&.*')
  ).test(text);
} 

@ryanseddon, wouldn't that over-compensate by escaping even non special characters? (Am now wondering if that's even a problem, or if the escape would be ignored/redundant in those cases)