Run results for: unique-props

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_6) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/13.0.1 Safari/605.1.15

Browser: Safari 13

Operating system: Mac OS X 10.14.6

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
unique - for...in	2976553.0 Ops/sec
unique - keys.reduce	1398017.0 Ops/sec
unique - set + reduce	378801.2 Ops/sec
unique - set + for...in	493278.8 Ops/sec

Script Preparation code:

function getUniqueProps0(objA = {}, objB = {}) {
  const diff = {};
  for (const key in objB) {
    if (!(key in objA)) {
      diff[key] = objB[key]
    }
  }

  return diff;
}

function getUniqueProps1(objA = {}, objB = {}) {
  return Object.keys(objB).reduce((diff, key) => {
    if (!(key in objA)) {
      diff[key] = objB[key];
    }

    return diff;
  }, {});
}

function getUniqueProps2(objA = {}, objB = {}) {
  const keySet = new Set(Object.keys(objA));

  return Object.keys(objB).reduce((diff, key) => {
    if (!keySet.has(key)) {
      diff[key] = objB[key];
    }

    return diff;
  }, {});
}

function getUniqueProps3(objA = {}, objB = {}) {
  const keySet = new Set(Object.keys(objA));

  const diff = {};

  for (const key in objB) {
    if (!keySet.has(key)) {
      diff[key] = objB[key];
    }
  }

  return diff;
}

Tests:

unique - for...in
const metaProps = { 'a': 1, 'b': 1, 'c': 1 }; const props = { 'b': 1, 'c': 1, 'd': 1 }; getUniqueProps0(metaProps, props);
unique - keys.reduce
const metaProps = { 'a': 1, 'b': 1, 'c': 1 }; const props = { 'b': 1, 'c': 1, 'd': 1 }; getUniqueProps1(metaProps, props);
unique - set + reduce
const metaProps = { 'a': 1, 'b': 1, 'c': 1 }; const props = { 'b': 1, 'c': 1, 'd': 1 }; getUniqueProps2(metaProps, props);
unique - set + for...in
const metaProps = { 'a': 1, 'b': 1, 'c': 1 }; const props = { 'b': 1, 'c': 1, 'd': 1 }; getUniqueProps3(metaProps, props);

Run results for: unique-props

unique - for...in

unique - keys.reduce

unique - set + reduce

unique - set + for...in