Helpers for getting values of specific Progressive Web App metrics

The pwmetrics module exposes the ability to get use performance metrics out of Lighthouse. This includes the ability to perform multiple runs. This module provides a simple API on top of pwmetrics for plucking out values of specific metrics.

Install

$ npm install --save pwmetrics-helper

Usage

desiredMetric

The desiredMetric field takes one of the following metrics and will return just that value from the median runs:

• 'First Contentful Paint'
• 'First Meaningful Paint'
• 'Perceptual Speed Index'
• 'First Visual Change'
• 'Visually Complete 100%'
• 'Time to Interactive'
• 'Visually Complete 85%'

Perform 3 runs (the default) and just return time-to-interactive:

const getMetrics = require('pwmetrics-helper');

getMetrics('https://airhorner.com', {
    desiredMetric: 'Time to Interactive'
}).then(score => {
    // do something with the score
});

Perform 2 runs and just return first-contentful-paint

const getMetrics = require('pwmetrics-helper');

getMetrics('https://airhorner.com', {
    runs: 2,
    desiredMetric: 'First Contentful Paint'
}).then(score => {
    // do something with the FCP
});

Perform 3 runs and return the entire JSON payload from pwmetrics

const getMetrics = require('pwmetrics-helper');

getMetrics('https://airhorner.com').then(data => {
    // do something with the data
});

runs

runs specifies the number of runs of Lighthouse to perform via pwmetrics before a median score is returned. This module generally defaults to 3 runs.

License

Apache 2.0. Google Inc.