Run results for: filter vs. groupBy (fixed)

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/101.0.4951.64 Safari/537.36 Edg/101.0.1210.53

Browser: Chrome 101

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
filter	7308563.0 Ops/sec
groupBy	4458575.0 Ops/sec

Tests:

filter
const posts = [ { id: 1, type: 'foo' }, { id: 2, type: 'bar' }, { id: 3, type: 'baz' }, { id: 4, type: 'foo' }, { id: 5, type: 'bar' }, { id: 6, type: 'baz' }, { id: 7, type: 'foo' }, { id: 8, type: 'bar' }, { id: 9, type: 'baz' } ]; posts.filter(p => p.type === 'foo').length; posts.filter(p => p.type === 'foo').length; posts.filter(p => p.type === 'foo').length; posts.filter(p => p.type === 'foo').length;
groupBy
const posts = [ { id: 1, type: 'foo' }, { id: 2, type: 'bar' }, { id: 3, type: 'baz' }, { id: 4, type: 'foo' }, { id: 5, type: 'bar' }, { id: 6, type: 'baz' }, { id: 7, type: 'foo' }, { id: 8, type: 'bar' }, { id: 9, type: 'baz' } ]; var groupBy = function(xs, key) { return xs.reduce(function(rv, x) { (rv[x[key]] = rv[x[key]] || []).push(x); return rv; }, {}); }; const postsByType = groupBy(posts, 'type') postsByType.foo.length; postsByType.bar.length; postsByType.baz.length; postsByType.foo.length;