Function findFirstIncompleteLevelOfPreviousPracticeChain

app/core/utils.js:990–1008

(levels, currentIndex)

}

const findFirstIncompleteLevelOfPreviousPracticeChain = function (levels, currentIndex) {
  let index = skipNonPracticeLevels(levels, currentIndex - 1)

  if (index >= 0) {
    index = skipPracticeLevels(levels, index)

    if (index >= 0) {
      index++

      // Skip completed practice levels
      while ((index < levels.length) && isPractice(levels[index]) && levels[index].complete) { index++ }

      if (isLocked(levels[index])) { return -1 }
      if (isPractice(levels[index]) && !levels[index].complete) { return index }
    }
  }

  return -1
}

const isAnyPrecedingLevelLocked = function (levels, currentIndex) {
  for (let i = 0, end = currentIndex, asc = end >= 0; asc ? i <= end : i >= end; asc ? i++ : i--) {