5 and 6 Kyu solutions

nextBigger.js

const nextBigger = (n) => {
  d = (''+n).split('')
  let pivot
  let numArray
  let min = 10
  let place
  for (let i = d.length - 2; i >= 0; i--) {
    if (d[i] < d[i + 1]) {
      numArray = d.slice(i + 1)
      pivot = d[i]
      for (var j = 0; j < numArray.length; j++) {
        if ((numArray[j] < min) && (numArray[j] > pivot)) {
          min = numArray[j]
          place = j
        }
      }
      d.splice(i, 1, min)
      numArray.splice(place, 1, pivot)
      return Number(d.slice(0, i + 1).concat(numArray.sort()).join(''))
    }
  }
  return -1
}

simplePigLatin.js

// https://www.codewars.com/kata/520b9d2ad5c005041100000f

const pigIt = (str) => {
  return str.split(' ').map((word) =>  word.substr(1) + word.substr(0, 1) + 'ay').join(' ')
}

snail.js

// https://www.codewars.com/kata/521c2db8ddc89b9b7a0000c1

const snail = (array) =>  {
  let result
  while (array.length) {
    result = (result ? result.concat(array.shift()) : array.shift())
    for (let i = 0; i < array.length; i++) {
      result.push(array[i].pop())
    }
    result = result.concat((array.pop() || []).reverse())
    for (let i = array.length - 1; i >= 0; i--) {
      result.push(array[i].shift())
    }
  }
  return result
}