Run results for: spread vs concat vs unshift vs push+sort

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:79.0) Gecko/20100101 Firefox/79.0

Browser: Firefox 79

Operating system: Mac OS X 10.15

Device Platform: Desktop

Date tested: 3 years ago

Script Preparation code:

var array = new Array();
for (let i = 1; i <= 1000; i++) {
  array.push(i);
}

Tests: