findMin.js

const findMin = array =>
  array.find(
    (item, index) => item < array[index > 0 ? index - 1 : array.length - 1]
  );

const findMinBinarySearch = (array, left = 0, right) => {
  if (right === undefined) right = array.length - 1;
  if (right - left === 0) return array[left];

  const midpoint = Math.floor(left + (right - left) / 2);
  // If the right most value of the LHS partition is less than the right most value in the RHS partition, then
  // we know that we need to search the LHS because we must have pivoted in the
  // LHS. (This could not be true otherwise.)
  // And vice versa.
  if (array[midpoint] < array[right]) {
    return findMinBinarySearch(array, left, midpoint);
  }
  return findMinBinarySearch(array, midpoint + 1, right);
};

console.log(findMin([7, 9, 0, 2, 4])); // 0
console.log(findMin([0, 2, 4, 7, 9])); // 0
console.log(findMin([2, 4, 7, 9, 0])); // 0

console.log(findMinBinarySearch([7, 9, 0, 2, 4])); // 0
console.log(findMinBinarySearch([0, 2, 4, 7, 9])); // 0
console.log(findMinBinarySearch([2, 4, 7, 9, 0])); // 0
console.log(findMinBinarySearch([2])); // 2