lighthouse-plugin-soft-navigation
v1.1.0
Published
Lighthouse plugin that reports metrics such as LCP and FCP from a soft navigation.
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7,695
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Lighthouse Soft Navigation Plugin
This is a plugin for Lighthouse that measures metrics such as FCP and LCP in a soft navigation.
Definition
A soft navigation is a same-document navigation triggered by user interaction that mutates the DOM and updates the page URL (e.g. using the history API). You can read more about the definition of a soft navigation over in WICG/softnavigations.
Requirements
Warning These features are necessary for this plugin to work but they are experimental and therefore subject to change without warning. I will try to keep the plugin and requirements up to date as things change.
- Use the latest Chrome Canary.
- Launch Chrome with
--enable-experimental-web-platform-features
to enable soft navigation measurement.
Installation
Install with npm or yarn. Make sure Lighthouse and Puppeteer are installed as well.
npm install lighthouse puppeteer lighthouse-plugin-soft-navigation
yarn add lighthouse puppeteer lighthouse-plugin-soft-navigation
Usage
Include this plugin in your Lighthouse config so Lighthouse timespan mode can audit interactions that trigger a soft navigation.
import fs from 'fs';
import puppeteer from 'puppeteer';
import {startFlow} from 'lighthouse';
const browser = await puppeteer.launch({
headless: false,
args: ['--enable-experimental-web-platform-features'],
// Make sure you are using the latest Chrome Canary.
executablePath: '/path/to/chrome'
});
const page = await browser.newPage();
const config = {
extends: 'lighthouse:default',
plugins: ['lighthouse-plugin-soft-navigation'],
}
const flow = await startFlow(page, {config});
// This will trigger a hard navigation.
// This step will be like any normal navigation in the report.
await flow.navigate('https://example.com');
// Clicking `a.link` will trigger a soft navigation.
// This step will include soft navigation metrics from the plugin in the report.
await flow.startTimespan();
await page.click('a.link');
await flow.endTimespan();
const report = await flow.generateReport();
fs.saveFileSync('report.html', report);