tinybit-critical-css-server

Standalone service to generate critical CSS, built on critical.

Install

Locally

Run on your local machine:

git clone git@github.com:pinchofyum/tinybit-critical-css-server.git
cd tinybit-critical-css-server
npm install
npm start

Google Cloud Function

Run as a Google Cloud Function:

1. Create a new Cloud Run Service.
2. Select "Continuously deploy new revisions from a source repository".
3. Fork this repository, then select it as the repository to build.
4. Build type will be "Dockerfile", because Puppeteer requires extra system dependencies.
5. Complete the rest of the Create Service steps. Minimum reqs seem to be 1 GB memory, 2 CPU.

Usage

tinybit-critical-css-server implements a simple HTTP API.

Simply POST / with html and css to receive css in response.

Check out tinybit-critical-css-plugin for integration with WordPress.

Testing

The test-src/ directory in this repository has a response.json with the CSS and HTML for an example request.

1. POST this data to the local critical CSS server started with npm run start.
2. Decode the JSON response and capture the return value for the css property.

• Save this to a response.json file in a WordPress project's wp-content directory
• wp shell
• $decoded = json_decode( file_get_contents( WP_CONTENT_DIR . '/response.json' ) )
• $decoded->css
• Paste in this project's response.css file.

3. Auto-format the CSS with VS Code's CSS Formatter and compare via diff with the stored version.

(These could be better automated, but we really don't update it a lot.)