Finally Aggregator

A simple utility for aggregating cleanup functions for async programming problems.

var FinallyAggregator = require('finally-aggregator');
var cleaner = new FinallyAggregator();

Example problem and solution

inParallel(
  [
    createTmpFile,
    performActionThatErrors
  ],
  function (err) {
    // how do I tell createTempFile to cleanup!?
  }
);

function createTmpFile(cleaner, next) {
  /// ...
  cleaner.add(cleanupTmpFile);
  next();
}
inParallel(
  [
    createTmpFile.bind(null, cleaner),
    performActionThatErrors.bind(null, cleaner)
  ],
  function (err) {
    if (err) cleaner.finish();
  }
);

What it does

1. The FinallyAggregator will queue up functions by using .add(fn).
2. Once .finish() is called all queued functions will execute.
3. If .add(fn) is called after .finish() it will execute immediately.

This lets us queue up cleanup if we have not reached a point where cleanup is desired, or perform cleanup if we have passed the point where cleanup is called for.