Codility Demo JavaScript

test.js

'use strict';
// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

/**
 *
 * @param {number[]} A
 * @returns {number}
 */
function solution(A) {
    // get rid of negatives
    const sorted = A.sort().filter((v) => v > 0);
    // return early if array consisted only of negatives
    if (sorted.length === 0) {
        return 1;
    }
    // handle edge case where array has length 1
    if (sorted.length === 1) {
        return sorted[0] > 1 ? 1 : 2;
    }

    let smallest = NaN
    for (let i = sorted.length - 1; i >= 1; i--) {

        if(sorted.length === 2){
            if(sorted[i] - sorted[i-1] <=1){
                smallest = sorted[i] +1
            }
            if(sorted[i-1] > 1){
                smallest = 1;
            }
        }

        if(sorted[i] - sorted[i-1] > 1){
            smallest = sorted[i-1] +1
        }

    }
    if(isNaN(smallest)){
       smallest = sorted[sorted.length -1] +1;
    }
    return smallest;
}

const a = [1, 2, 4, 6, 3]; // expected 5
const b = [-1, -3, 1]; // expected 2
const c = [-1, -3, 1, 2]; // expected 3
const d = [-1, -3, 1, 3]; // expected 2
const e = [-1, -3, 1, 2, 3, 5]; // expected 4
const f = [-1, -3, -21]; // expected 1
const g = [-1, -3, 3, 4]; // expected 1

const passes = [
    solution(a), // === 5 ? true : 'failed a',
    solution(b), // === 2 ? true : 'failed b',
    solution(c), // === 3 ? true : 'failed c',
    solution(d), // === 2 ? true : 'failed d',
    solution(e), // === 4 ? true : 'failed e',
    solution(f), // === 1 ? true : 'failed f',
    solution(g), // === 1 ? true : 'failed f',
];
const expected = [
    5,
    2,
    3,
    2,
    4,
    1,
    1
]
console.info("passes: ", passes)
console.info("expecd: ", expected)