function avoidObstacles(nums) {
    const sorted = nums.sort();
    const last = sorted.length - 1;
    let jumper = 0;
    
    for (i=2; i<sorted[last]; i++ ){
        const obstacleCheck = t => t%i !== 0;
        if (sorted.every(obstacleCheck)) return jumper = i;
    };
    return jumper;
};



/**
* Test Suite 
*/
describe('avoidObstacles()', () => {
    it('returns minimal number of jumps in between numbers', () => {
        // arrange
        const nums = [5, 3, 6, 7, 9];
        
        // act
        const result = avoidObstacles(nums);

        // log
        console.log("result: ", result);
        
        // assert
        expect(result).toBe(4);
    });
});