work.suroh.tk/node_modules/@11ty/eleventy/test/stubs/broken-config.js

const missingModule = require("this-is-a-module-that-does-not-exist");

module.exports = function(eleventyConfig) {
  eleventyConfig.addFilter("cssmin", function(code) {
    return missingModule(code);
  });

  return {};
};