const adjacentElementsProduct = nums => Math.max(...nums.map((c, i, a) => a[i+1] && [c, a[i+1]]).filter(e => Array.isArray(e)).map(e => e[0] * e[1]))



// function pairwise(arr, func){
//     for(var i=0; i < arr.length - 1; i++){
//         func(arr[i], arr[i + 1])
//     }
// }

// pairwise(arr, function(current, next){
//     console.log(current, next)
// })



/**
* Test Suite 
*/
describe('adjacentElementsProduct()', () => {
    it('returns largest product of adjacent values', () => {
        // arrange
        const nums = [3, 6, -2, -5, 7, 3];
        
        // act
        const result = adjacentElementsProduct(nums);

        // log
        console.log("result: ", result);
        
        // assert
        expect(result).toBe(21);
    });
});