Run results for: reduce spread vs reduce

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/102.0.0.0 Safari/537.36

Browser: Chrome 102

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
reduce spread	616725.6 Ops/sec
reduce 1	815794.9 Ops/sec
reduce without const	829360.9 Ops/sec

Script Preparation code:

var array = [{items: ['banana', 'jesus', 1212312, 2, 4, 'б', '112312312', 'dsdsdsds', 'sdsdsdsd', 'ergergergerg', '112312312', 'dsdsdsds', 'sdsdsdsd', 'ergergergerg', '112312312', 'dsdsdsds', 'sdsdsdsd', 'ergergergerg', '112312312', 'dsdsdsds', 'sdsdsdsd', 'ergergergerg', '112312312', 'dsdsdsds', 'sdsdsdsd', 'ergergergerg', '112312312', 'dsdsdsds', 'sdsdsdsd', 'ergergergerg', '112312312', 'sausage', 'dsdsdsds', 'sdsdsdsd', 'ergergergerg', '112312312', 'dsdsdsds', 'sdsdsdsd', 'ergergergerg', '112312312', 'dsdsdsds', 'sdsdsdsd', 'ergergergerg']},
             {items: ['banana', 'jesus', 1212312, 2, 4, 'б', '112312312', 'dsdsdsds', 'sdsdsdsd', 'ergergergerg', '112312312', 'dsdsdsds', 'sdsdsdsd', 'ergergergerg', '112312312', 'dsdsdsds', 'sdsdsdsd', 'ergergergerg', '112312312', 'dsdsdsds', 'sdsdsdsd', 'ergergergerg', '112312312', 'dsdsdsds', 'sdsdsdsd', 'ergergergerg', '112312312', 'dsdsdsds', 'sdsdsdsd', 'ergergergerg', '112312312', 'sausage', 'dsdsdsds', 'sdsdsdsd', 'ergergergerg', '112312312', 'dsdsdsds', 'sdsdsdsd', 'ergergergerg', '112312312', 'dsdsdsds', 'sdsdsdsd', 'ergergergerg']},
             {items: ['banana', 'jesus', 1212312, 2, 4, 'б', '112312312', 'dsdsdsds', 'sdsdsdsd', 'ergergergerg', '112312312', 'dsdsdsds', 'sdsdsdsd', 'ergergergerg', '112312312', 'dsdsdsds', 'sdsdsdsd', 'ergergergerg', '112312312', 'dsdsdsds', 'sdsdsdsd', 'ergergergerg', '112312312', 'dsdsdsds', 'sdsdsdsd', 'ergergergerg', '112312312', 'dsdsdsds', 'sdsdsdsd', 'ergergergerg', '112312312', 'sausage', 'dsdsdsds', 'sdsdsdsd', 'ergergergerg', '112312312', 'dsdsdsds', 'sdsdsdsd', 'ergergergerg', '112312312', 'dsdsdsds', 'sdsdsdsd', 'ergergergerg']}]

Tests:

reduce spread
array.reduce((acc, {items}) => { return [...acc, ...items.map((item) => item)]; }, []);
reduce 1
array.reduce((acc, {items}) => { const preparedItems = items.map((item) => { return {item}; }) acc.push(...preparedItems); return acc; }, []);
reduce without const
array.reduce((acc, {items}) => { acc.push(...items.map((item) => { return {item}; })); return acc; }, []);

Run results for: reduce spread vs reduce

reduce spread

reduce 1

reduce without const