How to use postcss-less - 4 common examples

function requireParser(isSCSSParser) {
  if (isSCSSParser) {
    return require("postcss-scss");
  }

  // TODO: Remove this hack when this issue is fixed:
  // https://github.com/shellscape/postcss-less/issues/88
  const LessParser = require("postcss-less/dist/less-parser");
  LessParser.prototype.atrule = function() {
    return Object.getPrototypeOf(LessParser.prototype).atrule.apply(
      this,
      arguments
    );
  };

  return require("postcss-less");
}

switch (fileNameExtension(file)) {

                case "sass":
                    console.error('TODO: Sass not implemented yet, file will be empty!');
                    postcssSass.process(code).result.root;
                    sassFiles++;
                    break;
                case "scss":
                    console.error('TODO: Sass not implemented yet, file will be empty!');
                    postcssScss.parse(code);
                    scssFiles++;
                    break;
                case "less":
                    console.error('TODO: Sass not implemented yet, file will be empty!');
                    postcssLess.parse(code);
                    lessFiles++;
                    break;
                case "css":
                    tss = transformCSStoTSS(postcssCss.parse(code));
                    destinationFile = destinationFile.replace('.css', '.tss.ts');
                    cssFiles++;
            }

            if (!existsSync(destinationDirectory)) {
                mkdirSync(destinationDirectory);
            }

            process.chdir(destinationDirectory);

            writeFileSync(destinationFile, tss);

LessParser.prototype.atrule = function() {
    return Object.getPrototypeOf(LessParser.prototype).atrule.apply(
      this,
      arguments
    );
  };

parse (source) {
        return postcss([]).process(source, {
            from: this.fullPath,
            parser: postcssLess.parse,
            stringifier: postcssLess.stringify,
        });
    }