To add benchmark test for a js library/code, or npm package

Create a performance test similar to below code;

var Benchmark = require('benchmark');

var id = "sample001"; //Manadatory
var suite = new Benchmark.Suite(id);
// add tests 
suite.add('RegExp#test', function() {
  /o/.test('Hello World!');
})
.add('String#indexOf', function() {
  'Hello World!'.indexOf('o') > -1;
})

module.exports = suite

Now either submit it via creating an issue on github. Or add yourself.
To add yourself,

• go to tests folder. Add the above test. (check archived folder for more ideas)
• Add profile entry
• Add dev dependency in package.json (if any)
• run npm run benchmarktest
• check if a new file is generated in reports folder