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jsPerf.app is an online JavaScript performance benchmark test runner & jsperf.com mirror. It is a complete rewrite in homage to the once excellent jsperf.com now with hopefully a more modern & maintainable codebase.

jsperf.com URLs are mirrored at the same path, e.g:

https://jsperf.com/negative-modulo/2

Can be accessed at:

https://jsperf.app/negative-modulo/2

Test case details

Title *

Description
(Markdown syntax is allowed)

Preparation Code

Preparation HTML
(this will be inserted in the <body> of a valid HTML5 document in standards mode)
(useful when testing DOM operations or including libraries)

Setup JS

const testHeaders = `
Content-Type: application/json
Authorization: Bearer token123
Accept-Language: en-US
User-Agent: Mozilla/5.0
Cache-Control: no-cache
Connection: keep-alive
Host: example.com
Accept: */*
Content-Length: 123
`

Teardown JS

Test cases

Test #1

Title *

Async

Code *

const headersWithFlatMap = Object.fromEntries( testHeaders .split(/\r?\n/) .flatMap((line) => { const match = /^([\w-]+): (.+)$/.exec(line); return match ? [[match[1], match[2]]] : []; }) );

Test #2

Title *

Async

Code *

const headersWithMapFilter = Object.fromEntries( testHeaders .split(/\r?\n/) .map((line) => { const match = /^([\w-]+): (.+)$/.exec(line); return match ? [match[1], match[2]] : null; }) .filter(Boolean) );