Run results for: Big Sample Set: Performance of uniqueBy using new Map or reducing to an object, also comparing for..in and Object.values for extracting values

Compare performance between the native Object.values(obj) function vs the lodash _.values() option and a function that extracts the values of an object using a for...in loop.

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_6) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/14.0 Safari/605.1.15

Browser: Safari 14

Operating system: Mac OS X 10.15.6

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
unique by map, extract with deconstruct	680647.3 Ops/sec
obj UniqueBy, extract with for...in loop	839015.4 Ops/sec
obj UniqueBy, extract with Object.values()	706118.9 Ops/sec
unique by map, extract with ArrayFrom	621695.5 Ops/sec

Script Preparation code:

function uniqueBy(list, predicate, extractor) {
 	const a = new Map(list.map(l => [predicate(l), l]))
    return extractor(a)
}

function extractorDeconstruct(iterator) {
	return [...iterator.values()]
}

function extractorArrayFrom(iterator) {
 	return Array.from(iterator) 
}

function objUniqueBy(list, predicate, extractor) {
    const a = list.reduce((acc, val) => Object.assign(acc, { [predicate(val)]: val }), {})
    return extractor(a)
}

function badUniqueBy(list, predicate, extractor) {
	const keyValuePairs = list.reduce((map, value) => {
     return { ...map, [predicate(value)]: value }
   }, {})
    return extractor(keyValuePairs);
}


function extractValuesForIn(obj) {
   const t = [];
   for(var key in obj) { t.push(obj[key]); }
   return t;
}

function extractValuesObject(obj) {
  return Object.values(obj);
}

function getData() {
return [{a:0,c:1},{a:1,c:1},{a:2,c:1},{a:3,c:1},{a:4,c:1},{a:5,c:1},{a:6,c:1},{a:7,c:1},{a:8,c:1},{a:9,c:1},{a:10,c:1},{a:11,c:1},{a:12,c:1},{a:13,c:1},{a:14,c:1},{a:15,c:1},{a:16,c:1},{a:17,c:1},{a:18,c:1},{a:19,c:1},{a:20,c:1},{a:21,c:1},{a:22,c:1},{a:23,c:1},{a:24,c:1},{a:25,c:1},{a:26,c:1},{a:27,c:1},{a:28,c:1},{a:29,c:1},{a:30,c:1},{a:31,c:1},{a:32,c:1},{a:33,c:1},{a:34,c:1},{a:35,c:1},{a:36,c:1},{a:37,c:1},{a:38,c:1},{a:39,c:1},{a:40,c:1},{a:41,c:1},{a:42,c:1},{a:43,c:1},{a:44,c:1},{a:45,c:1},{a:46,c:1},{a:47,c:1},{a:48,c:1},{a:49,c:1},{a:0,c:1},{a:1,c:1},{a:2,c:1},{a:3,c:1},{a:4,c:1},{a:5,c:1},{a:6,c:1},{a:7,c:1},{a:8,c:1},{a:9,c:1},{a:10,c:1},{a:11,c:1},{a:12,c:1},{a:13,c:1},{a:14,c:1},{a:15,c:1},{a:16,c:1},{a:17,c:1},{a:18,c:1},{a:19,c:1},{a:20,c:1},{a:21,c:1},{a:22,c:1},{a:23,c:1},{a:24,c:1},{a:25,c:1},{a:26,c:1},{a:27,c:1},{a:28,c:1},{a:29,c:1},{a:30,c:1},{a:31,c:1},{a:32,c:1},{a:33,c:1},{a:34,c:1},{a:35,c:1},{a:36,c:1},{a:37,c:1},{a:38,c:1},{a:39,c:1},{a:40,c:1},{a:41,c:1},{a:42,c:1},{a:43,c:1},{a:44,c:1},{a:45,c:1},{a:46,c:1},{a:47,c:1},{a:48,c:1},{a:49,c:1}]
}

Tests:

unique by map, extract with deconstruct
uniqueBy(getData(), (x) => x['a'], extractorDeconstruct)
obj UniqueBy, extract with for...in loop
objUniqueBy(getData(), (x) => x['a'], extractValuesForIn);
obj UniqueBy, extract with Object.values()
objUniqueBy(getData(), (x) => x['a'], extractValuesObject);
unique by map, extract with ArrayFrom
uniqueBy(getData(), (x) => x['a'], extractorArrayFrom)
bad uniqueBy, reducer has an array deconstructor
badUniqueBy(getData(), (x) => x['a'], extractValuesForIn);

Run results for: Big Sample Set: Performance of uniqueBy using new Map or reducing to an object, also comparing for..in and Object.values for extracting values

Compare performance between the native Object.values(obj) function vs the lodash _.values() option and a function that extracts the values of an object using a for...in loop.

unique by map, extract with deconstruct

obj UniqueBy, extract with for...in loop

obj UniqueBy, extract with Object.values()

unique by map, extract with ArrayFrom

bad uniqueBy, reducer has an array deconstructor