Run results for: Object spread, object assign - MeasureThat.net

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.88 Safari/537.36

Browser: Chrome 87

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
Assign spread	433354.0 Ops/sec
Assign mutate	2526856.0 Ops/sec
Assign Immutable	1794185.1 Ops/sec
Copy spread	8966020.0 Ops/sec
Copy assign	2448191.0 Ops/sec
assign spread inline	1179124.8 Ops/sec
assign inline mutate	3629800.5 Ops/sec
assign inline copy	2076535.0 Ops/sec

Script Preparation code:

var test1 = { a: 1, b: 2, c: 3 };
var test2 = { d: 4, e: 5, f: 6 };

Tests:

Assign spread
const assignSpread = { ...test1, ...test2 };
Assign mutate
const assignMutate = Object.assign(test1, test2);
Assign Immutable
const assignImmutable = Object.assign({}, test1, test2);
Copy spread
const copySpread = { ...test1 };
Copy assign
const copyAssign = Object.assign({}, test1);
assign spread inline
const assignSpreadInline = { ...test1, x: 1 };
assign inline mutate
const assignInlineMutate = Object.assign(test1, { x: 1 });
assign inline copy
const assignInlineCopy = Object.assign({}, test1, { x: 1 });