Run results for: Object spread, object assign

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 14_2_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/14.0.1 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 14

Operating system: iOS 14.2.1

Device Platform: Mobile

Date tested: 4 years ago

Test name	Executions per second
Assign spread	738612.6 Ops/sec
Assign mutate	1813285.8 Ops/sec
Assign Immutable	1324139.2 Ops/sec
Copy spread	880388.0 Ops/sec
Copy assign	1879174.1 Ops/sec
assign spread inline	847121.2 Ops/sec
assign inline mutate	2586076.2 Ops/sec
assign inline copy	1561835.1 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 });

Run results for: Object spread, object assign

Assign spread

Assign mutate

Assign Immutable

Copy spread

Copy assign

assign spread inline

assign inline mutate

assign inline copy