gol.js

function getGOL(size) {


  return function(matrix) {
    const result = [];

    for (let x = 0; x < matrix.length; x++) {
      result[x] = [];
      for (let y = 0; y < matrix.length; y++) {
        const count = countNeighbours(matrix, x, y);
        const alive = matrix[x][y];
        
        if (!alive) {
          if (count === 3) result[x][y] = true;
        } else {
          if (count === 1 || count === 0) result[x][y] = false;
          if (count === 2 || count === 3) result[x][y] = true;
          if (count > 3) result[x][y] = false;
        }
      }
    }

    return result;
  }
}

function countNeighbours(matrix, x, y) {
  let count = 0;
  let size = matrix.length;

  let left = (x == 0) ? size-1 : x - 1;
  let right = (x == size-1) ? 0 : x + 1;
  let top = (y == size-1) ? 0 : y + 1;
  let bottom = (y == 0) ? size-1 : y - 1;

console.log(x, y)
console.log(left, right, top, bottom);

  if (matrix[left][y]) count++;
  if (matrix[left][top]) count++;
  if (matrix[x][top]) count++;
  if (matrix[right][top]) count++;
  if (matrix[right][y]) count++;
  if (matrix[right][bottom]) count++;
  if (matrix[x][bottom]) count++;
  if (matrix[left][bottom]) count++;

  return count;
}

module.exports = getGOL;