Run results for: array spread operator vs concat fix

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/117.0.0.0 Safari/537.36

Browser: Chrome 117

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
spread big	67946.4 Ops/sec
concat big	980272.1 Ops/sec
spread small	7087222.5 Ops/sec
concat small	4895113.5 Ops/sec
spread big smal	541482.4 Ops/sec
spread small big	89966.5 Ops/sec
concat big small	1536843.0 Ops/sec
concat small big	1576727.1 Ops/sec
shallow copy spread	2251571.8 Ops/sec
shallow copy concat	2186087.8 Ops/sec

Script Preparation code:

var a = Array.from({length: 1000}).map((_, i)=>`${i}`);
var b = Array.from({length: 2000}).map((_, i)=>`${i}`);
var aSmall = ['a', 'b', 'c', 'd'];
var bSmall = ['e', 'f', 'g', 'h', 'i'];

Tests:

spread big
const c = [...a, ...b];
concat big
const c = a.concat(b);
spread small
const c = [...aSmall, ...bSmall];
concat small
const c = aSmall.concat(bSmall);
spread big smal
const c = [...b, ...bSmall];
spread small big
const c = [...bSmall, ...b];
concat big small
const c = b.concat(bSmall);
concat small big
const c = bSmall.concat(b);
shallow copy spread
const c = [...b];
shallow copy concat
const c = [].concat(b);

Run results for: array spread operator vs concat fix

spread big

concat big

spread small

concat small

spread big smal

spread small big

concat big small

concat small big

shallow copy spread

shallow copy concat