gatsby-lighthouse-cli

Run lighthouse on your gatsby app locally.

How to use it

yarn add gatsby-lighthouse-cli --dev

It exposes the functionality through a binary, which you can call e.g. in your package json scripts:

{
  "scripts": {
    "lighthouse": "gatsby-lighthouse --performance=100 --accessibility=100"
  }
}

CLI Args

--performance

Threshold for performance category (number between 1 and 100). If not specified, no threshold will be applied. The CLI will still display the score.

--pwa, --accessibility, --best-practises, --seo

Same for other categories.

--show-errors

Shows all metrics of the audit that have a score less than 100.

--silent

Don't output any logs.

--port

The port your gatsby app will be served on for the audit (defaults to 9001)

Config

⚠️ This is still work in progress, the below is just a plan atm

Ideally you can override the lighthouse and chrome configs easily. The best way would be a gatsby-lighthouse-config.js file that automatically gets detected. An additional option would be via cli argument --config allowing to specify a specific file path to pick up the config, which would allow having multiple configs for different testing scenarios.

How does it work?

It's pretty simple. All this library does is starting up an express server that serves your gatsby app. It then launches a headless instance of chrome and runs lighthouse with the given config and checks the resulting scores against any given thresholds. If a score is lower than a given threshold, the command will exit with code 1, allowing you to use it e.g. in pre-commit hooks or CI preventing deployments.

Similar projects

Inspired by https://github.com/ivanoats/gatsby-lighthouse and https://github.com/andreasonny83/lighthouse-ci.

julianburr / gatsby-lighthouse-cli