Run results for: Array.concat and Babel ES5

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/85.0.4183.38 Safari/537.36

Browser: Chrome 85

Operating system: Mac OS X 10.12.3

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
Babel	741471.1 Ops/sec
New array concat	2217255.0 Ops/sec
Exist array concat	2465640.0 Ops/sec

Script Preparation code:

var previousContexts = [123, 456, 678, 123, 456, 678, 123, 456, 678, 123, 456, 678, 123, 456, 678, 123, 456, 678];
var newCallContexts = [123, 456, 678, 123, 456, 678, 123, 456, 678, 123, 456, 678, 123, 456, 678, 123, 456, 678];

Tests:

Babel
function _toConsumableArray(arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) { arr2[i] = arr[i]; } return arr2; } else { return Array.from(arr); } } var joined = [].concat( _toConsumableArray(previousContexts), _toConsumableArray(newCallContexts) );
New array concat
var joined = [].concat(previousContexts, newCallContexts);
Exist array concat
var joined = previousContexts.concat(newCallContexts);

Run results for: Array.concat and Babel ES5

Babel

New array concat

Exist array concat