async.filter() as a standalone module, in the interest of modularity and smaller bundle size.

npm install async-filter-each --save

var filter = require('async-filter-each')

filter(filenames, fs.exists, function (results) {
  // results are now filtered down to files which exist
  console.log(results)
})

Returns a new array of all the values in items which pass an async truth test. The callback for each iterator call only accepts a single argument of true or false; it does not accept an error argument first! This is in-line with the way node libraries work with truth tests like fs.exists. This operation is performed in parallel, but the results array will be in the same order as the original.

Arguments:

• items
  An array to iterate over.
• iterator(item, callback)
  A truth test to apply to each item in arr. The iterator is passed a callback(truthValue), which must be called with a boolean argument once it has completed.
• callback(results)
  (optional) A callback which is called after all the iterator functions have finished.

MIT, see LICENSE.md for details.