export function moveEnemies(gameState) {
  let level = currentLevel(gameState);

  level.enemies = reduce(
    level.enemies,
    (aggregate, enemy) => {
      let results = map(
        aroundPlayer(gameState),
        a => moveEnemyTowards(
          enemy,
          a,
          level,
          aggregate)
      );

      results = reject(results, isNull);
      results = reject(results, r => locationEqual(r, enemy));
      results = [first(results) || enemy];
      return concat(aggregate, results);
    },
    []
  );
}