MDN browser-compat-data collector

Data collection service for MDN's browser-compat-data. Live at https://mdn-bcd-collector.gooborg.com/. Latest main available at https://staging.mdn-bcd-collector.gooborg.com/.

Feature detection tests are generated based on machine-readable data (Web IDL and CSS definitions) from web standards, with support for custom tests where needed. Results are submitted to the mdn-bcd-results repository.

This service is part of an effort to assist BCD updates with automation, and exists to run lots of small tests in browsers to determine the support status of a feature in a browser, and save those results.

Copyright

© 2023 Gooborg Studios + Open Web Docs + various contributors, © 2020-2022 Google LLC, Mozilla Corporation and Gooborg Studios.

This project is under the Apache License 2.0 license. See the LICENSE file for more details.

Setup

This project requires Node.js 18 through 20.

npm install

Updating BCD using the results

See docs/update-bcd.md for information on how to use the update-bcd script.

Reviewing BCD changes

See docs/reviewing-bcd-changes.md for information on reviewing changes made by the collector.

Running the server locally

npm run dev

(dev, as opposed to start, will use ts-node to run the TypeScript file, as well as automatically rebuild the tests and reload the server on file changes.)

To also handle HTTPS traffic, use the --https-cert and --https-key arguments:

npm run dev -- --https-cert=my-cert.pem --https-key=my-cert.key

Running tests via Selenium WebDriver

A script has been provided which will collect all of the results for nearly all of the browsers, using the Selenium WebDriver to control your CTs, and download them to your computer (which can then be submitted as a PR). To run this script, you'll need a few prerequisites:

• A clone of mdn-bcd-results adjacent to this folder's repository (or at least a folder at ../mdn-bcd-results)
• At least one Selenium remote (ex. BrowserStack, SauceLabs, etc.)

Define Selenium Hosts

In secrets.json, you'll need to add your Selenium remote(s). In the selenium object, define your remote(s) by setting the key as the service name (ex. "browserstack", "saucelabs", "lambdatest", "custom", etc.) and the value as either an object containing the username and key for known remotes, or simply a string of the remote URL. Your secrets.json should look something like this:

{
  "github": {
    "token": "github-token-goes-here"
  },
  "selenium": {
    "browserstack": {
      "username": "example",
      "key": "some-API-key-goes-here"
    },
    "saucelabs": {
      "username": "example",
      "key": "some-API-key-goes-here",
      "region": "us-west-1"
    },
    "lambdatest": {
      "username": "example",
      "key": "some-API-key-goes-here"
    },
    "custom": "https://my.example.page.org/selenium/wd"
  }
}

Currently, the Selenium hosts known to the script are:

• BrowserStack - requires username and key
• SauceLabs - requires username, key, and region
• LambdaTest - requires username and key

You may use other Selenium hosts, but please be aware that they have not been tested and you may experience unexpected results.

Run the script

To test using the latest deployed version, run:

npm run selenium

You can also limit the browsers to test by defining browsers as arguments:

npm run selenium chrome
npm run selenium edge ie

Additionally, you can limit the browser versions by the year with the --since argument (default: 2020):

npm run selenium -- --since=2016
npm run selenium firefox -- --since=2000 # Grab all versions of Firefox

Running the unit tests and linter

npm test

Code coverage reports can be viewed in a browser by running:

npm run coverage

Cleaning up generated files

npm run clean