Splitting test files into roughly similar buckets

bucket-split.js

// Files vs. tests in file
var files = {
  'one.js': 12,
  'two.js': 22,
  'three.js': 14,
  'four.js': 10,
  'five.js': 19,
  'six.js': 10,
  'seven.js': 18,
  'eight.js': 10,
  'nine.js': 10,
  'ten.js': 50,
  'eleven.js': 2,
  'twelve.js': 32,
  'thirteen.js': 9,
  'fourteen.js': 12,
  'fifteen.js': 40,
  'sixteen.js': 23,
  'seventeen.js': 44,
  'eighteen.js': 25,
  'nineteen.js': 12,
  'twenty.js': 29,
  'twentyone.js': 88,
};

// Split a "ring" in two as well as possible
var halve = function(ring){
  var midPoint = ring.length / 2;
  var upperSlicePoint = Math.ceil(midPoint);
  var lowerSlicePoint = Math.floor(midPoint);

  var midFile = ring[upperSlicePoint];

  var upperFile = midFile;
  while (upperFile == midFile){
    upperSlicePoint++;
    upperFile = ring[upperSlicePoint];
  } 

  var lowerFile = midFile;
  while (lowerFile == midFile){
    lowerSlicePoint--;
    lowerFile = ring[lowerSlicePoint];
  } 

  // Pick the upper or lower slice point; whichever is closest to the middle
  if ((midPoint - lowerSlicePoint) > (upperSlicePoint - midPoint)){
    return [
      ring.slice(0, upperSlicePoint),
      ring.slice(upperSlicePoint, ring.length)
    ];
  } else {
    return [
      ring.slice(0, lowerSlicePoint+1),
      ring.slice(lowerSlicePoint+1, ring.length)
    ];
  }

};

// Get unique elements from an array
var uniq = function(items){
  var map = {};
  for (var i in items){
    map[items[i]] = true;
  }
  var keys = [];
  for (var key in map){
    if (map.hasOwnProperty(key)){
      keys.push(key);
    }
  }
  return keys;
};

////////////////////////
// Meat is below here //
////////////////////////

// Not actually a ring, but fuck it
var ring = [];

// Fill the "ring" with filenames; repeat each file testCount times
for (var file in files){
  var testCount = files[file];
  for (var i = 0; i < testCount; ++i){
    ring.push(file);
  }
}

// Split into 4 buckets
var halves  = halve(ring);
var buckets = halve(halves[0]).concat(halve(halves[1]));

// Remove duplicates from the buckets and we're done. 
buckets = buckets.map(uniq);

// See how many tests (and files) are in each bucket
for (var i in buckets){
  var bucket = buckets[i];
  var testCount = 0;
  for (var j in bucket){
    testCount += files[bucket[j]];
  }
  console.log("Bucket "+ i +" contains "+ bucket.length +" files and "+ testCount +" tests");
}