JavaScript Performance

JavaScript performance is a collection of utilities that can help you to give information about the performance of your application.

Bear in mind that this is not a jsperf sibling, but it's more focused on something else.

The library is simply a easy way to take advantage of the browser API performance

Why JavaScript Performance?

The browser API performance is useful but it takes a bit to understand the APIs and make an effective use inside your application.

The aim of the library is just to give few functions with almost zero learning curve.

How to install

Just run the following command

npm install --save @ematipico/js-performance

How to import it

Import the library in the way of prefer most, from your browser

<script src='path/to/js.performance.umd.js'></script>
<script>
  JSPerf.startRecording()

  // etc.
</script>

Or straight inside your modules if you are using bundler such as webpack or rollup

import { startRecording } from 'js-perf'

startRecording()
// etc.

The library doesn't support Node.js environments for obvious reasons, as it doesn't have a performance API.

How to use it

The following example will use ES6 modules and it will be really simple

import { startRecording, startMark, stopMark, stopRecording, allMeasures  } from 'js-perf'

startRecording()

startMark('firstLoop')
for (let i = 0; i < 100; i++) {
  // operation
}
stopMark('firstLoop')

startMark('secondLoop')
for (let i = 0; i < 100; i++) {
  // operation
}
stopMark('secondLoop')
stopRecording()
allMeasures() // this will print inside your console the results of your marks

It's easy!

Note: at the moment the library does not support having two marks with the same name

That means that executing the following code won't work

import { startRecording, startMark, stopMark, stopRecording  } from 'js-perf'

startRecording()
startMark('operation')
startMark('operation')

// expensive operation

stopMark('operation')
stopMark('operation')
stopRecording()

The result will be just ONE mark called 'operation'

APIs

A list of available APIs is here