html-minimizer-webpack-plugin/dist/minify.js

"use strict";

const minify = async options => {
  const minifyFns = typeof options.minify === "function" ? [options.minify] : options.minify;
  const result = {
    code: options.input,
    warnings: [],
    errors: []
  };

  for (let i = 0; i <= minifyFns.length - 1; i++) {
    const minifyFn = minifyFns[i];
    const minifyOptions = Array.isArray(options.minimizerOptions) ? options.minimizerOptions[i] : options.minimizerOptions; // eslint-disable-next-line no-await-in-loop

    const minifyResult = await minifyFn({
      [options.name]: result.code
    }, minifyOptions);

    if (Object.prototype.toString.call(minifyResult) === "[object Object]" && minifyResult !== null && "code" in minifyResult) {
      result.code = minifyResult.code;
      result.warnings = result.warnings.concat(minifyResult.warnings || []);
      result.errors = result.errors.concat(minifyResult.errors || []);
    } else {
      result.code = minifyResult;
    }
  }

  return result;
};

async function transform(options) {
  // 'use strict' => this === undefined (Clean Scope)
  // Safer for possible security issues, albeit not critical at all here
  // eslint-disable-next-line no-new-func, no-param-reassign
  options = new Function("exports", "require", "module", "__filename", "__dirname", `'use strict'\nreturn ${options}`)(exports, require, module, __filename, __dirname);
  return minify(options);
}

module.exports.minify = minify;
module.exports.transform = transform;