minimalcss-server

A Node Express server with a pool of puppeteer browsers sent into minimalcss that analyzes the minimal CSS for a URL.

To run:

node server.js

To test:

curl -X POST  -H 'Content-Type: application/json' \
  -d '{"url": "https://news.ycombinator.com"}' \
  http://localhost:5000/minimize

It uses a pool of opened puppeteer browser instances created with launch args args: ['--no-sandbox', '--disable-setuid-sandbox']. These are then sent to minimalcss and its output is returned as JSON by this server. It looks something like this:

{
    "result": {
        "finalCss": "[SNIP]",
        "stylesheetContents": {
            "https://news.ycombinator.com/news.css?tcSCuEkwhnkVn0z07QWM":
                "[SNIP]"
        },
        "_url": "https://news.ycombinator.com",
        "_took": 3454.6355110000004,
        "_cache": "miss"
    }
}

An LRU cache protects for repeated calls. If there's a cache hit on the LRU the exact same output is returned by result._took === 0.0 and result._cache === 'hit'.

Skippable URLs

By default minimalcss doesn't skip any URLs. However, there are some good defaults that almost everyone should skip. One of them is Google Analytics JS and another is Google Fonts.

The reason you should skip Google Fonts is because a URL like https://fonts.googleapis.com/css?family=Lato is dynamic. It's content is different depending the browser. If you let minimalcss include its content it will be based on the user agent that minimalcss is.

If you want to add other patterns, you can pass in skippable_url_patterns. For example:

curl -X POST  -H 'Content-Type: application/json' \
  -d '{"url": "https://example.com", "skippable_url_patterns": ["ads.example.com"]}' \
  http://localhost:5000/minimize

Prettier

If you include "prettier": true in your JSON body POST, the returning JSON will have one additional key called _prettier which is the result of running prettier.format(result.finalCss, {parser: "css"}).