index.ts

import * as htmlMinifier from "html-minifier";
import { MinifyStep } from "@shanzhai/minify-step";

/**
 * Minifies HTML source.
 */
export class MinifyHtmlStep extends MinifyStep<string> {
  /**
   * @inheritdoc
   */
  readonly maximumIterations = 10;

  /**
   * @inheritdoc
   */
  async iterate(value: string): Promise<string> {
    return htmlMinifier.minify(value, {
      caseSensitive: false,
      collapseBooleanAttributes: true,
      collapseInlineTagWhitespace: true,
      collapseWhitespace: true,
      conservativeCollapse: false,
      decodeEntities: true,
      html5: true,
      includeAutoGeneratedTags: false,
      keepClosingSlash: false,
      minifyCSS: true,
      minifyJS: false,
      minifyURLs: false,
      preserveLineBreaks: false,
      preventAttributesEscaping: false,
      processConditionalComments: false,
      removeAttributeQuotes: true,
      removeComments: true,
      removeEmptyAttributes: true,
      removeEmptyElements: true,
      removeOptionalTags: true,
      removeRedundantAttributes: true,
      removeScriptTypeAttributes: true,
      removeStyleLinkTypeAttributes: true,
      removeTagWhitespace: true,
      sortAttributes: true,
      sortClassName: true,
      trimCustomFragments: true,
      useShortDoctype: true,
    });
  }
}