meteor/tools/tests/standard-minification.js

import selftest, {Sandbox} from '../tool-testing/selftest.js';

selftest.define('standard-minifiers - CSS splitting', function (options) {
  const s = new Sandbox({
    clients: options.clients
  });

  s.createApp('myapp', 'minification-css-splitting');
  s.cd('myapp');

  s.testWithAllClients(function (run) {
    run.waitSecs(5);
    run.match('myapp');
    run.match('proxy');
    run.match('MongoDB');
    run.match('your app');
    run.match('running at');
    run.match('localhost');

    run.connectClient();
    run.waitSecs(20);
    run.match('client connected');

    run.match('the number of stylesheets: <2>');
    run.match('the color of the tested 4097th property: <rgb(0, 128, 0)>');

    s.append('client/lots-of-styles.main.styl', `
.class-4097
  color: blue
`);

    run.waitSecs(60);
    run.match('Client modified -- refreshing');
    run.match('the number of stylesheets: <2>');
    run.match('the color of the tested 4097th property: <rgb(0, 0, 255)>');

    run.stop();
  }, '--production');
});