Workaround for BusterJS EMFILE problem – https://github.com/busterjs/buster/issues/347

__description.md

Workaround a.k.a. deep-down-the-rabbit-hole hack for busterjs EMFILE problem somehow OSX decided that 256 of open files is enough for each process :) re: busterjs/buster#347

Contains of the executable buster-test-workaround.js, which could be used as drop-in replacement for buster-test.

And second file grunt_options_buster.js helps to point your grunt task to the workaround executable instead of original buster-test.

buster-test-workaround.js

#!/usr/bin/env node
// workaround for buster-test cli executable
// could be called from command line the same way as `buster-test`
// with all the arguments and whatnot
//
// To make it work you'd need to install `graceful-fs` module
// from here: https://www.npmjs.org/package/graceful-fs
//
// Also it expects `buster-test` to be installed locally within your project
// if you're using global `buster` command update `originalBusterTest` accordingly
//
// Don't forget to make it executable

var originalBusterTest = './node_modules/.bin/buster-test';

// "better" fs
var fs = require('graceful-fs');
// override file-resolver
var fileResolver = require('buster/node_modules/buster-test-cli/node_modules/buster-cli/node_modules/buster-configuration/node_modules/ramp-resources/lib/resource-file-resolver.js');
// extra allowances for promises
var when = require('buster/node_modules/when');

fileResolver._prepareResource = fileResolver.prepareResource;
fileResolver.prepareResource = function(rootPath, path, resource)
{
  var promise = fileResolver._prepareResource(rootPath, path, resource);
  var fileName = fileResolver.absolutePath(rootPath, path);
  // replace original resource.content method
  // with new shiny thing
  resource.content = resourceContent.bind(resource, fileName);

  return promise;
};

// require original buster-test
// to make it part of the process
require(originalBusterTest);

// new content resolver
function resourceContent(fileName)
{
    var d = when.defer();
    fs.readFile(fileName, this.encoding, function (err, data) {
        if (err) { return d.resolver.reject(err); }
        d.resolver.resolve(data);
    });
    return d.promise;
};

grunt_options_buster.js

// In case if you're using `grunt-buster`
// this is extra piece for your grunt job config file
// overrides `grunt-buster`s cmd.findExecutable method
// to point to the workaround file

module.exports =
{
  // your grunt-buster options
};

// Workaround a.k.a. deep-down-the-rabbit-hole hack
// resolves `buster-test` into custom workaround file
// leaving as is everything else

var gruntBuster = require('grunt-buster/tasks/buster/cmd');
gruntBuster._findExecutable = gruntBuster.findExecutable;
gruntBuster.findExecutable = function(cmd, callback)
{
// site/buster-test-workaround.js
  return gruntBuster._findExecutable(cmd, function(err, candidate)
  {
    // create middleman to continue with faking fs module
    // for the executable down below
    if (!err && cmd == 'buster-test')
    {
      candidate = './buster-test-workaround.js';
    }

    return callback(err, candidate);
  });
};