code:
'use strict';

var CleanCSS = require('clean-css');
var decode = require('he').decode;
var HTMLParser = require('./htmlparser').HTMLParser;
var endTag = require('./htmlparser').endTag;
var RelateUrl = require('relateurl');
var TokenChain = require('./tokenchain');
var Terser = require('terser');
var utils = require('./utils');

function trimWhitespace(str) {
  return str && str.replace(/^[ \n\r\t\f]+/, '').replace(/[ \n\r\t\f]+$/, '');
}

function collapseWhitespaceAll(str) {
  // Non-breaking space is specifically handled inside the replacer function here:
  return str && str.replace(/[ \n\r\t\f\xA0]+/g, function(spaces) {
    return spaces === '\t' ? '\t' : spaces.replace(/(^|\xA0+)[^\xA0]+/g, '$1 ');
  });
}

function collapseWhitespace(str, options, trimLeft, trimRight, collapseAll) {
  var lineBreakBefore = '', lineBreakAfter = '';

  if (options.preserveLineBreaks) {
    str = str.replace(/^[ \n\r\t\f]*?[\n\r][ \n\r\t\f]*/, function() {
      lineBreakBefore = '\n';
      return '';
    }).replace(/[ \n\r\t\f]*?[\n\r][ \n\r\t\f]*$/, function() {
      lineBreakAfter = '\n';
      return '';
    });
  }

  if (trimLeft) {
    // Non-breaking space is specifically handled inside the replacer function here:
    str = str.replace(/^[ \n\r\t\f\xA0]+/, function(spaces) {
      var conservative = !lineBreakBefore && options.conservativeCollapse;
      if (conservative && spaces === '\t') {
        return '\t';
      }
      return spaces.replace(/^[^\xA0]+/, '').replace(/(\xA0+)[^\xA0]+/g, '$1 ') || (conservative ? ' ' : '');
    });
  }

  if (trimRight) {
    // Non-breaking space is specifically handled inside the replacer function here:
    str = str.replace(/[ \n\r\t\f\xA0]+$/, function(spaces) {
      var conservative = !lineBreakAfter && options.conservativeCollapse;
      if (conservative && spaces === '\t') {
        return '\t';
      }
      return spaces.replace(/[^\xA0]+(\xA0+)/g, ' $1').replace(/[^\xA0]+$/, '') || (conservative ? ' ' : '');
    });
  }

  if (collapseAll) {
    // strip non space whitespace then compress spaces to one
    str = collapseWhitespaceAll(str);
  }

  return lineBreakBefore + str + lineBreakAfter;
}

var createMapFromString = utils.createMapFromString;
// non-empty tags that will maintain whitespace around them
var inlineTags = createMapFromString('a,abbr,acronym,b,bdi,bdo,big,button,cite,code,del,dfn,em,font,i,ins,kbd,label,mark,math,nobr,object,q,rp,rt,rtc,ruby,s,samp,select,small,span,strike,strong,sub,sup,svg,textarea,time,tt,u,var');
// non-empty tags that will maintain whitespace within them
var inlineTextTags = createMapFromString('a,abbr,acronym,b,big,del,em,font,i,ins,kbd,mark,nobr,rp,s,samp,small,span,strike,strong,sub,sup,time,tt,u,var');
// self-closing tags that will maintain whitespace around them
var selfClosingInlineTags = createMapFromString('comment,img,input,wbr');

function collapseWhitespaceSmart(str, prevTag, nextTag, options) {
  var trimLeft = prevTag && !selfClosingInlineTags(prevTag);
  if (trimLeft && !options.collapseInlineTagWhitespace) {
    trimLeft = prevTag.charAt(0) === '/' ? !inlineTags(prevTag.slice(1)) : !inlineTextTags(prevTag);
  }
  var trimRight = nextTag && !selfClosingInlineTags(nextTag);
  if (trimRight && !options.collapseInlineTagWhitespace) {
    trimRight = nextTag.charAt(0) === '/' ? !inlineTextTags(nextTag.slice(1)) : !inlineTags(nextTag);
  }
  return collapseWhitespace(str, options, trimLeft, trimRight, prevTag && nextTag);
}

function isConditionalComment(text) {
  return /^\[if\s[^\]]+]|\[endif]$/.test(text);
}

function isIgnoredComment(text, options) {
  for (var i = 0, len = options.ignoreCustomComments.length; i < len; i++) {
    if (options.ignoreCustomComments[i].test(text)) {
      return true;
    }
  }
  return false;
}

function isEventAttribute(attrName, options) {
  var patterns = options.customEventAttributes;
  if (patterns) {
    for (var i = patterns.length; i--;) {
      if (patterns[i].test(attrName)) {
        return true;
      }
    }
    return false;
  }
  return /^on[a-z]{3,}$/.test(attrName);
}

function canRemoveAttributeQuotes(value) {
  // https://mathiasbynens.be/notes/unquoted-attribute-values
  return /^[^ \t\n\f\r"'`=<>]+$/.test(value);
}

function attributesInclude(attributes, attribute) {
  for (var i = attributes.length; i--;) {
    if (attributes[i].name.toLowerCase() === attribute) {
      return true;
    }
  }
  return false;
}

function isAttributeRedundant(tag, attrName, attrValue, attrs) {
  attrValue = attrValue ? trimWhitespace(attrValue.toLowerCase()) : '';

  return (
    tag === 'script' &&
    attrName === 'language' &&
    attrValue === 'javascript' ||

    tag === 'form' &&
    attrName === 'method' &&
    attrValue === 'get' ||

    tag === 'input' &&
    attrName === 'type' &&
    attrValue === 'text' ||

    tag === 'script' &&
    attrName === 'charset' &&
    !attributesInclude(attrs, 'src') ||

    tag === 'a' &&
    attrName === 'name' &&
    attributesInclude(attrs, 'id') ||

    tag === 'area' &&
    attrName === 'shape' &&
    attrValue === 'rect'
  );
}

// https://mathiasbynens.be/demo/javascript-mime-type
// https://developer.mozilla.org/en/docs/Web/HTML/Element/script#attr-type
var executableScriptsMimetypes = utils.createMap([
  'text/javascript',
  'text/ecmascript',
  'text/jscript',
  'application/javascript',
  'application/x-javascript',
  'application/ecmascript',
  'module'
]);

var keepScriptsMimetypes = utils.createMap([
  'module'
]);

function isScriptTypeAttribute(attrValue) {
  attrValue = trimWhitespace(attrValue.split(/;/, 2)[0]).toLowerCase();
  return attrValue === '' || executableScriptsMimetypes(attrValue);
}

function keepScriptTypeAttribute(attrValue) {
  attrValue = trimWhitespace(attrValue.split(/;/, 2)[0]).toLowerCase();
  return keepScriptsMimetypes(attrValue);
}

function isExecutableScript(tag, attrs) {
  if (tag !== 'script') {
    return false;
  }
  for (var i = 0, len = attrs.length; i < len; i++) {
    var attrName = attrs[i].name.toLowerCase();
    if (attrName === 'type') {
      return isScriptTypeAttribute(attrs[i].value);
    }
  }
  return true;
}

function isStyleLinkTypeAttribute(attrValue) {
  attrValue = trimWhitespace(attrValue).toLowerCase();
  return attrValue === '' || attrValue === 'text/css';
}

function isStyleSheet(tag, attrs) {
  if (tag !== 'style') {
    return false;
  }
  for (var i = 0, len = attrs.length; i < len; i++) {
    var attrName = attrs[i].name.toLowerCase();
    if (attrName === 'type') {
      return isStyleLinkTypeAttribute(attrs[i].value);
    }
  }
  return true;
}

var isSimpleBoolean = createMapFromString('allowfullscreen,async,autofocus,autoplay,checked,compact,controls,declare,default,defaultchecked,defaultmuted,defaultselected,defer,disabled,enabled,formnovalidate,hidden,indeterminate,inert,ismap,itemscope,loop,multiple,muted,nohref,noresize,noshade,novalidate,nowrap,open,pauseonexit,readonly,required,reversed,scoped,seamless,selected,sortable,truespeed,typemustmatch,visible');
var isBooleanValue = createMapFromString('true,false');

function isBooleanAttribute(attrName, attrValue) {
  return isSimpleBoolean(attrName) || attrName === 'draggable' && !isBooleanValue(attrValue);
}

function isUriTypeAttribute(attrName, tag) {
  return (
    /^(?:a|area|link|base)$/.test(tag) && attrName === 'href' ||
    tag === 'img' && /^(?:src|longdesc|usemap)$/.test(attrName) ||
    tag === 'object' && /^(?:classid|codebase|data|usemap)$/.test(attrName) ||
    tag === 'q' && attrName === 'cite' ||
    tag === 'blockquote' && attrName === 'cite' ||
    (tag === 'ins' || tag === 'del') && attrName === 'cite' ||
    tag === 'form' && attrName === 'action' ||
    tag === 'input' && (attrName === 'src' || attrName === 'usemap') ||
    tag === 'head' && attrName === 'profile' ||
    tag === 'script' && (attrName === 'src' || attrName === 'for')
  );
}

function isNumberTypeAttribute(attrName, tag) {
  return (
    /^(?:a|area|object|button)$/.test(tag) && attrName === 'tabindex' ||
    tag === 'input' && (attrName === 'maxlength' || attrName === 'tabindex') ||
    tag === 'select' && (attrName === 'size' || attrName === 'tabindex') ||
    tag === 'textarea' && /^(?:rows|cols|tabindex)$/.test(attrName) ||
    tag === 'colgroup' && attrName === 'span' ||
    tag === 'col' && attrName === 'span' ||
    (tag === 'th' || tag === 'td') && (attrName === 'rowspan' || attrName === 'colspan')
  );
}

function isLinkType(tag, attrs, value) {
  if (tag !== 'link') {
    return false;
  }
  for (var i = 0, len = attrs.length; i < len; i++) {
    if (attrs[i].name === 'rel' && attrs[i].value === value) {
      return true;
    }
  }
}

function isMediaQuery(tag, attrs, attrName) {
  return attrName === 'media' && (isLinkType(tag, attrs, 'stylesheet') || isStyleSheet(tag, attrs));
}

var srcsetTags = createMapFromString('img,source');

function isSrcset(attrName, tag) {
  return attrName === 'srcset' && srcsetTags(tag);
}

async function cleanAttributeValue(tag, attrName, attrValue, options, attrs) {
  if (isEventAttribute(attrName, options)) {
    attrValue = trimWhitespace(attrValue).replace(/^javascript:\s*/i, '');
    return await options.minifyJS(attrValue, true);
  }
  else if (attrName === 'class') {
    attrValue = trimWhitespace(attrValue);
    if (options.sortClassName) {
      attrValue = options.sortClassName(attrValue);
    }
    else {
      attrValue = collapseWhitespaceAll(attrValue);
    }
    return attrValue;
  }
  else if (isUriTypeAttribute(attrName, tag)) {
    attrValue = trimWhitespace(attrValue);
    return isLinkType(tag, attrs, 'canonical') ? attrValue : options.minifyURLs(attrValue);
  }
  else if (isNumberTypeAttribute(attrName, tag)) {
    return trimWhitespace(attrValue);
  }
  else if (attrName === 'style') {
    attrValue = trimWhitespace(attrValue);
    if (attrValue) {
      if (/;$/.test(attrValue) && !/&#?[0-9a-zA-Z]+;$/.test(attrValue)) {
        attrValue = attrValue.replace(/\s*;$/, ';');
      }
      attrValue = options.minifyCSS(attrValue, 'inline');
    }
    return attrValue;
  }
  else if (isSrcset(attrName, tag)) {
    // https://html.spec.whatwg.org/multipage/embedded-content.html#attr-img-srcset
    attrValue = trimWhitespace(attrValue).split(/\s+,\s*|\s*,\s+/).map(function(candidate) {
      var url = candidate;
      var descriptor = '';
      var match = candidate.match(/\s+([1-9][0-9]*w|[0-9]+(?:\.[0-9]+)?x)$/);
      if (match) {
        url = url.slice(0, -match[0].length);
        var num = +match[1].slice(0, -1);
        var suffix = match[1].slice(-1);
        if (num !== 1 || suffix !== 'x') {
          descriptor = ' ' + num + suffix;
        }
      }
      return options.minifyURLs(url) + descriptor;
    }).join(', ');
  }
  else if (isMetaViewport(tag, attrs) && attrName === 'content') {
    attrValue = attrValue.replace(/\s+/g, '').replace(/[0-9]+\.[0-9]+/g, function(numString) {
      // "0.90000" -> "0.9"
      // "1.0" -> "1"
      // "1.0001" -> "1.0001" (unchanged)
      return (+numString).toString();
    });
  }
  else if (isContentSecurityPolicy(tag, attrs) && attrName.toLowerCase() === 'content') {
    return collapseWhitespaceAll(attrValue);
  }
  else if (options.customAttrCollapse && options.customAttrCollapse.test(attrName)) {
    attrValue = trimWhitespace(attrValue.replace(/ ?[\n\r]+ ?/g, '').replace(/\s{2,}/g, options.conservativeCollapse ? ' ' : ''));
  }
  else if (tag === 'script' && attrName === 'type') {
    attrValue = trimWhitespace(attrValue.replace(/\s*;\s*/g, ';'));
  }
  else if (isMediaQuery(tag, attrs, attrName)) {
    attrValue = trimWhitespace(attrValue);
    return options.minifyCSS(attrValue, 'media');
  }
  return attrValue;
}

function isMetaViewport(tag, attrs) {
  if (tag !== 'meta') {
    return false;
  }
  for (var i = 0, len = attrs.length; i < len; i++) {
    if (attrs[i].name === 'name' && attrs[i].value === 'viewport') {
      return true;
    }
  }
}

function isContentSecurityPolicy(tag, attrs) {
  if (tag !== 'meta') {
    return false;
  }
  for (var i = 0, len = attrs.length; i < len; i++) {
    if (attrs[i].name.toLowerCase() === 'http-equiv' && attrs[i].value.toLowerCase() === 'content-security-policy') {
      return true;
    }
  }
}

function ignoreCSS(id) {
  return '/* clean-css ignore:start */' + id + '/* clean-css ignore:end */';
}

// Wrap CSS declarations for CleanCSS > 3.x
// See https://github.com/jakubpawlowicz/clean-css/issues/418
function wrapCSS(text, type) {
  switch (type) {
    case 'inline':
      return '*{' + text + '}';
    case 'media':
      return '@media ' + text + '{a{top:0}}';
    default:
      return text;
  }
}

function unwrapCSS(text, type) {
  var matches;
  switch (type) {
    case 'inline':
      matches = text.match(/^\*\{([\s\S]*)\}$/);
      break;
    case 'media':
      matches = text.match(/^@media ([\s\S]*?)\s*{[\s\S]*}$/);
      break;
  }
  return matches ? matches[1] : text;
}

async function cleanConditionalComment(comment, options) {
  return options.processConditionalComments ? await utils.replaceAsync(comment, /^(\[if\s[^\]]+]>)([\s\S]*?)(<!\[endif])$/, async function(match, prefix, text, suffix) {
    return prefix + await minify(text, options, true) + suffix;
  }) : comment;
}

async function processScript(text, options, currentAttrs) {
  for (var i = 0, len = currentAttrs.length; i < len; i++) {
    if (currentAttrs[i].name.toLowerCase() === 'type' &&
        options.processScripts.indexOf(currentAttrs[i].value) > -1) {
      return await minify(text, options);
    }
  }
  return text;
}

// Tag omission rules from https://html.spec.whatwg.org/multipage/syntax.html#optional-tags
// with the following deviations:
// - retain <body> if followed by <noscript>
// - </rb>, </rt>, </rtc>, </rp> & </tfoot> follow https://www.w3.org/TR/html5/syntax.html#optional-tags
// - retain all tags which are adjacent to non-standard HTML tags
var optionalStartTags = createMapFromString('html,head,body,colgroup,tbody');
var optionalEndTags = createMapFromString('html,head,body,li,dt,dd,p,rb,rt,rtc,rp,optgroup,option,colgroup,caption,thead,tbody,tfoot,tr,td,th');
var headerTags = createMapFromString('meta,link,script,style,template,noscript');
var descriptionTags = createMapFromString('dt,dd');
var pBlockTags = createMapFromString('address,article,aside,blockquote,details,div,dl,fieldset,figcaption,figure,footer,form,h1,h2,h3,h4,h5,h6,header,hgroup,hr,main,menu,nav,ol,p,pre,section,table,ul');
var pInlineTags = createMapFromString('a,audio,del,ins,map,noscript,video');
var rubyTags = createMapFromString('rb,rt,rtc,rp');
var rtcTag = createMapFromString('rb,rtc,rp');
var optionTag = createMapFromString('option,optgroup');
var tableContentTags = createMapFromString('tbody,tfoot');
var tableSectionTags = createMapFromString('thead,tbody,tfoot');
var cellTags = createMapFromString('td,th');
var topLevelTags = createMapFromString('html,head,body');
var compactTags = createMapFromString('html,body');
var looseTags = createMapFromString('head,colgroup,caption');
var trailingTags = createMapFromString('dt,thead');
var htmlTags = createMapFromString('a,abbr,acronym,address,applet,area,article,aside,audio,b,base,basefont,bdi,bdo,bgsound,big,blink,blockquote,body,br,button,canvas,caption,center,cite,code,col,colgroup,command,content,data,datalist,dd,del,details,dfn,dialog,dir,div,dl,dt,element,em,embed,fieldset,figcaption,figure,font,footer,form,frame,frameset,h1,h2,h3,h4,h5,h6,head,header,hgroup,hr,html,i,iframe,image,img,input,ins,isindex,kbd,keygen,label,legend,li,link,listing,main,map,mark,marquee,menu,menuitem,meta,meter,multicol,nav,nobr,noembed,noframes,noscript,object,ol,optgroup,option,output,p,param,picture,plaintext,pre,progress,q,rb,rp,rt,rtc,ruby,s,samp,script,section,select,shadow,small,source,spacer,span,strike,strong,style,sub,summary,sup,table,tbody,td,template,textarea,tfoot,th,thead,time,title,tr,track,tt,u,ul,var,video,wbr,xmp');

function canRemoveParentTag(optionalStartTag, tag) {
  switch (optionalStartTag) {
    case 'html':
    case 'head':
      return true;
    case 'body':
      return !headerTags(tag);
    case 'colgroup':
      return tag === 'col';
    case 'tbody':
      return tag === 'tr';
  }
  return false;
}

function isStartTagMandatory(optionalEndTag, tag) {
  switch (tag) {
    case 'colgroup':
      return optionalEndTag === 'colgroup';
    case 'tbody':
      return tableSectionTags(optionalEndTag);
  }
  return false;
}

function canRemovePrecedingTag(optionalEndTag, tag) {
  switch (optionalEndTag) {
    case 'html':
    case 'head':
    case 'body':
    case 'colgroup':
    case 'caption':
      return true;
    case 'li':
    case 'optgroup':
    case 'tr':
      return tag === optionalEndTag;
    case 'dt':
    case 'dd':
      return descriptionTags(tag);
    case 'p':
      return pBlockTags(tag);
    case 'rb':
    case 'rt':
    case 'rp':
      return rubyTags(tag);
    case 'rtc':
      return rtcTag(tag);
    case 'option':
      return optionTag(tag);
    case 'thead':
    case 'tbody':
      return tableContentTags(tag);
    case 'tfoot':
      return tag === 'tbody';
    case 'td':
    case 'th':
      return cellTags(tag);
  }
  return false;
}

var reEmptyAttribute = new RegExp(
  '^(?:class|id|style|title|lang|dir|on(?:focus|blur|change|click|dblclick|mouse(' +
    '?:down|up|over|move|out)|key(?:press|down|up)))$');

function canDeleteEmptyAttribute(tag, attrName, attrValue, options) {
  var isValueEmpty = !attrValue || /^\s*$/.test(attrValue);
  if (!isValueEmpty) {
    return false;
  }
  if (typeof options.removeEmptyAttributes === 'function') {
    return options.removeEmptyAttributes(attrName, tag);
  }
  return tag === 'input' && attrName === 'value' || reEmptyAttribute.test(attrName);
}

function hasAttrName(name, attrs) {
  for (var i = attrs.length - 1; i >= 0; i--) {
    if (attrs[i].name === name) {
      return true;
    }
  }
  return false;
}

function canRemoveElement(tag, attrs) {
  switch (tag) {
    case 'textarea':
      return false;
    case 'audio':
    case 'script':
    case 'video':
      if (hasAttrName('src', attrs)) {
        return false;
      }
      break;
    case 'iframe':
      if (hasAttrName('src', attrs) || hasAttrName('srcdoc', attrs)) {
        return false;
      }
      break;
    case 'object':
      if (hasAttrName('data', attrs)) {
        return false;
      }
      break;
    case 'applet':
      if (hasAttrName('code', attrs)) {
        return false;
      }
      break;
  }
  return true;
}

function canCollapseWhitespace(tag) {
  return !/^(?:script|style|pre|textarea)$/.test(tag);
}

function canTrimWhitespace(tag) {
  return !/^(?:pre|textarea)$/.test(tag);
}

async function normalizeAttr(attr, attrs, tag, options) {
  var attrName = options.name(attr.name),
      attrValue = attr.value;

  if (options.decodeEntities && attrValue) {
    attrValue = decode(attrValue, { isAttributeValue: true });
  }

  if (options.removeRedundantAttributes &&
    isAttributeRedundant(tag, attrName, attrValue, attrs) ||
    options.removeScriptTypeAttributes && tag === 'script' &&
    attrName === 'type' && isScriptTypeAttribute(attrValue) && !keepScriptTypeAttribute(attrValue) ||
    options.removeStyleLinkTypeAttributes && (tag === 'style' || tag === 'link') &&
    attrName === 'type' && isStyleLinkTypeAttribute(attrValue)) {
    return;
  }

  if (attrValue) {
    attrValue = await cleanAttributeValue(tag, attrName, attrValue, options, attrs);
  }

  if (options.removeEmptyAttributes &&
      canDeleteEmptyAttribute(tag, attrName, attrValue, options)) {
    return;
  }

  if (options.decodeEntities && attrValue) {
    attrValue = attrValue.replace(/&(#?[0-9a-zA-Z]+;)/g, '&$1');
  }

  return {
    attr: attr,
    name: attrName,
    value: attrValue
  };
}

function buildAttr(normalized, hasUnarySlash, options, isLast, uidAttr) {
  var attrName = normalized.name,
      attrValue = normalized.value,
      attr = normalized.attr,
      attrQuote = attr.quote,
      attrFragment,
      emittedAttrValue;

  if (typeof attrValue !== 'undefined' && (!options.removeAttributeQuotes ||
      ~attrValue.indexOf(uidAttr) || !canRemoveAttributeQuotes(attrValue))) {
    if (!options.preventAttributesEscaping) {
      if (typeof options.quoteCharacter === 'undefined') {
        var apos = (attrValue.match(/'/g) || []).length;
        var quot = (attrValue.match(/"/g) || []).length;
        attrQuote = apos < quot ? '\'' : '"';
      }
      else {
        attrQuote = options.quoteCharacter === '\'' ? '\'' : '"';
      }
      if (attrQuote === '"') {
        attrValue = attrValue.replace(/"/g, '"');
      }
      else {
        attrValue = attrValue.replace(/'/g, ''');
      }
    }
    emittedAttrValue = attrQuote + attrValue + attrQuote;
    if (!isLast && !options.removeTagWhitespace) {
      emittedAttrValue += ' ';
    }
  }
  // make sure trailing slash is not interpreted as HTML self-closing tag
  else if (isLast && !hasUnarySlash && !/\/$/.test(attrValue)) {
    emittedAttrValue = attrValue;
  }
  else {
    emittedAttrValue = attrValue + ' ';
  }

  if (typeof attrValue === 'undefined' || options.collapseBooleanAttributes &&
      isBooleanAttribute(attrName.toLowerCase(), attrValue.toLowerCase())) {
    attrFragment = attrName;
    if (!isLast) {
      attrFragment += ' ';
    }
  }
  else {
    attrFragment = attrName + attr.customAssign + emittedAttrValue;
  }

  return attr.customOpen + attrFragment + attr.customClose;
}

function identity(value) {
  return value;
}

function processOptions(values) {
  var options = {
    name: function(name) {
      return name.toLowerCase();
    },
    canCollapseWhitespace: canCollapseWhitespace,
    canTrimWhitespace: canTrimWhitespace,
    html5: true,
    ignoreCustomComments: [
      /^!/,
      /^\s*#/
    ],
    ignoreCustomFragments: [
      /<%[\s\S]*?%>/,
      /<\?[\s\S]*?\?>/
    ],
    includeAutoGeneratedTags: true,
    log: identity,
    minifyCSS: identity,
    minifyJS: identity,
    minifyURLs: identity
  };
  Object.keys(values).forEach(function(key) {
    var value = values[key];
    if (key === 'caseSensitive') {
      if (value) {
        options.name = identity;
      }
    }
    else if (key === 'log') {
      if (typeof value === 'function') {
        options.log = value;
      }
    }
    else if (key === 'minifyCSS' && typeof value !== 'function') {
      if (!value) {
        return;
      }
      if (typeof value !== 'object') {
        value = {};
      }
      options.minifyCSS = function(text, type) {
        text = text.replace(/(url\s*\(\s*)("|'|)(.*?)\2(\s*\))/ig, function(match, prefix, quote, url, suffix) {
          return prefix + quote + options.minifyURLs(url) + quote + suffix;
        });
        var cleanCssOutput = new CleanCSS(value).minify(wrapCSS(text, type));
        if (cleanCssOutput.errors.length > 0) {
          cleanCssOutput.errors.forEach(options.log);
          return text;
        }
        return unwrapCSS(cleanCssOutput.styles, type);
      };
    }
    else if (key === 'minifyJS' && typeof value !== 'function') {
      if (!value) {
        return;
      }
      if (typeof value !== 'object') {
        value = {};
      }
      (value.parse || (value.parse = {})).bare_returns = false;
      options.minifyJS = async function(text, inline) {
        var start = text.match(/^\s*<!--.*/);
        var code = start ? text.slice(start[0].length).replace(/\n\s*-->\s*$/, '') : text;
        value.parse.bare_returns = inline;
        try {
          const result = await Terser.minify(code, value);
          return result.code.replace(/;$/, '');
        }
        catch (error) {
          options.log(error);
          return text;
        }
      };
    }
    else if (key === 'minifyURLs' && typeof value !== 'function') {
      if (!value) {
        return;
      }
      if (typeof value === 'string') {
        value = { site: value };
      }
      else if (typeof value !== 'object') {
        value = {};
      }
      options.minifyURLs = function(text) {
        try {
          return RelateUrl.relate(text, value);
        }
        catch (err) {
          options.log(err);
          return text;
        }
      };
    }
    else {
      options[key] = value;
    }
  });
  return options;
}

function uniqueId(value) {
  var id;
  do {
    id = Math.random().toString(36).replace(/^0\.[0-9]*/, '');
  } while (~value.indexOf(id));
  return id;
}

var specialContentTags = createMapFromString('script,style');

async function createSortFns(value, options, uidIgnore, uidAttr) {
  var attrChains = options.sortAttributes && Object.create(null);
  var classChain = options.sortClassName && new TokenChain();

  function attrNames(attrs) {
    return attrs.map(function(attr) {
      return options.name(attr.name);
    });
  }

  function shouldSkipUID(token, uid) {
    return !uid || token.indexOf(uid) === -1;
  }

  function shouldSkipUIDs(token) {
    return shouldSkipUID(token, uidIgnore) && shouldSkipUID(token, uidAttr);
  }

  async function scan(input) {
    var currentTag, currentType;
    const parser = new HTMLParser(input, {
      start: function(tag, attrs) {
        if (attrChains) {
          if (!attrChains[tag]) {
            attrChains[tag] = new TokenChain();
          }
          attrChains[tag].add(attrNames(attrs).filter(shouldSkipUIDs));
        }
        for (var i = 0, len = attrs.length; i < len; i++) {
          var attr = attrs[i];
          if (classChain && attr.value && options.name(attr.name) === 'class') {
            classChain.add(trimWhitespace(attr.value).split(/[ \t\n\f\r]+/).filter(shouldSkipUIDs));
          }
          else if (options.processScripts && attr.name.toLowerCase() === 'type') {
            currentTag = tag;
            currentType = attr.value;
          }
        }
      },
      end: function() {
        currentTag = '';
      },
      chars: async function(text) {
        if (options.processScripts && specialContentTags(currentTag) &&
            options.processScripts.indexOf(currentType) > -1) {
          await scan(text);
        }
      }
    });

    await parser.parse();
  }

  var log = options.log;
  options.log = identity;
  options.sortAttributes = false;
  options.sortClassName = false;
  await scan(await minify(value, options));
  options.log = log;
  if (attrChains) {
    var attrSorters = Object.create(null);
    for (var tag in attrChains) {
      attrSorters[tag] = attrChains[tag].createSorter();
    }
    options.sortAttributes = function(tag, attrs) {
      var sorter = attrSorters[tag];
      if (sorter) {
        var attrMap = Object.create(null);
        var names = attrNames(attrs);
        names.forEach(function(name, index) {
          (attrMap[name] || (attrMap[name] = [])).push(attrs[index]);
        });
        sorter.sort(names).forEach(function(name, index) {
          attrs[index] = attrMap[name].shift();
        });
      }
    };
  }
  if (classChain) {
    var sorter = classChain.createSorter();
    options.sortClassName = function(value) {
      return sorter.sort(value.split(/[ \n\f\r]+/)).join(' ');
    };
  }
}

async function minify(value, options, partialMarkup) {
  if (options.collapseWhitespace) {
    value = collapseWhitespace(value, options, true, true);
  }

  var buffer = [],
      charsPrevTag,
      currentChars = '',
      hasChars,
      currentTag = '',
      currentAttrs = [],
      stackNoTrimWhitespace = [],
      stackNoCollapseWhitespace = [],
      optionalStartTag = '',
      optionalEndTag = '',
      ignoredMarkupChunks = [],
      ignoredCustomMarkupChunks = [],
      uidIgnore,
      uidAttr,
      uidPattern;

  // temporarily replace ignored chunks with comments,
  // so that we don't have to worry what's there.
  // for all we care there might be
  // completely-horribly-broken-alien-non-html-emoj-cthulhu-filled content
  value = value.replace(/<!-- htmlmin:ignore -->([\s\S]*?)<!-- htmlmin:ignore -->/g, function(match, group1) {
    if (!uidIgnore) {
      uidIgnore = uniqueId(value);
      var pattern = new RegExp('^' + uidIgnore + '([0-9]+)$');
      if (options.ignoreCustomComments) {
        options.ignoreCustomComments = options.ignoreCustomComments.slice();
      }
      else {
        options.ignoreCustomComments = [];
      }
      options.ignoreCustomComments.push(pattern);
    }
    var token = '<!--' + uidIgnore + ignoredMarkupChunks.length + '-->';
    ignoredMarkupChunks.push(group1);
    return token;
  });

  var customFragments = options.ignoreCustomFragments.map(function(re) {
    return re.source;
  });
  if (customFragments.length) {
    var reCustomIgnore = new RegExp('\\s*(?:' + customFragments.join('|') + ')+\\s*', 'g');
    // temporarily replace custom ignored fragments with unique attributes
    value = value.replace(reCustomIgnore, function(match) {
      if (!uidAttr) {
        uidAttr = uniqueId(value);
        uidPattern = new RegExp('(\\s*)' + uidAttr + '([0-9]+)' + uidAttr + '(\\s*)', 'g');
        if (options.minifyCSS) {
          options.minifyCSS = (function(fn) {
            return function(text, type) {
              text = text.replace(uidPattern, function(match, prefix, index) {
                var chunks = ignoredCustomMarkupChunks[+index];
                return chunks[1] + uidAttr + index + uidAttr + chunks[2];
              });
              var ids = [];
              new CleanCSS().minify(wrapCSS(text, type)).warnings.forEach(function(warning) {
                var match = uidPattern.exec(warning);
                if (match) {
                  var id = uidAttr + match[2] + uidAttr;
                  text = text.replace(id, ignoreCSS(id));
                  ids.push(id);
                }
              });
              text = fn(text, type);
              ids.forEach(function(id) {
                text = text.replace(ignoreCSS(id), id);
              });
              return text;
            };
          })(options.minifyCSS);
        }
        if (options.minifyJS) {
          options.minifyJS = (function(fn) {
            return function(text, type) {
              return fn(text.replace(uidPattern, function(match, prefix, index) {
                var chunks = ignoredCustomMarkupChunks[+index];
                return chunks[1] + uidAttr + index + uidAttr + chunks[2];
              }), type);
            };
          })(options.minifyJS);
        }
      }
      var token = uidAttr + ignoredCustomMarkupChunks.length + uidAttr;
      ignoredCustomMarkupChunks.push(/^(\s*)[\s\S]*?(\s*)$/.exec(match));
      return '\t' + token + '\t';
    });
  }

  if (options.sortAttributes && typeof options.sortAttributes !== 'function' ||
      options.sortClassName && typeof options.sortClassName !== 'function') {
    await createSortFns(value, options, uidIgnore, uidAttr);
  }

  function _canCollapseWhitespace(tag, attrs) {
    return options.canCollapseWhitespace(tag, attrs, canCollapseWhitespace);
  }

  function _canTrimWhitespace(tag, attrs) {
    return options.canTrimWhitespace(tag, attrs, canTrimWhitespace);
  }

  function removeStartTag() {
    var index = buffer.length - 1;
    while (index > 0 && !/^<[^/!]/.test(buffer[index])) {
      index--;
    }
    buffer.length = Math.max(0, index);
  }

  function removeEndTag() {
    var index = buffer.length - 1;
    while (index > 0 && !/^<\//.test(buffer[index])) {
      index--;
    }
    buffer.length = Math.max(0, index);
  }

  // look for trailing whitespaces, bypass any inline tags
  function trimTrailingWhitespace(index, nextTag) {
    for (var endTag = null; index >= 0 && _canTrimWhitespace(endTag); index--) {
      var str = buffer[index];
      var match = str.match(/^<\/([\w:-]+)>$/);
      if (match) {
        endTag = match[1];
      }
      else if (/>$/.test(str) || (buffer[index] = collapseWhitespaceSmart(str, null, nextTag, options))) {
        break;
      }
    }
  }

  // look for trailing whitespaces from previously processed text
  // which may not be trimmed due to a following comment or an empty
  // element which has now been removed
  function squashTrailingWhitespace(nextTag) {
    var charsIndex = buffer.length - 1;
    if (buffer.length > 1) {
      var item = buffer[buffer.length - 1];
      if (/^(?:<!|$)/.test(item) && item.indexOf(uidIgnore) === -1) {
        charsIndex--;
      }
    }
    trimTrailingWhitespace(charsIndex, nextTag);
  }

  const parser = new HTMLParser(value, {
    partialMarkup: partialMarkup,
    continueOnParseError: options.continueOnParseError,
    customAttrAssign: options.customAttrAssign,
    customAttrSurround: options.customAttrSurround,
    html5: options.html5,

    start: async function(tag, attrs, unary, unarySlash, autoGenerated) {
      if (tag.toLowerCase() === 'svg') {
        options = Object.create(options);
        options.caseSensitive = true;
        options.keepClosingSlash = true;
        options.name = identity;
      }
      tag = options.name(tag);
      currentTag = tag;
      charsPrevTag = tag;
      if (!inlineTextTags(tag)) {
        currentChars = '';
      }
      hasChars = false;
      currentAttrs = attrs;

      var optional = options.removeOptionalTags;
      if (optional) {
        var htmlTag = htmlTags(tag);
        // <html> may be omitted if first thing inside is not comment
        // <head> may be omitted if first thing inside is an element
        // <body> may be omitted if first thing inside is not space, comment, <meta>, <link>, <script>, <style> or <template>
        // <colgroup> may be omitted if first thing inside is <col>
        // <tbody> may be omitted if first thing inside is <tr>
        if (htmlTag && canRemoveParentTag(optionalStartTag, tag)) {
          removeStartTag();
        }
        optionalStartTag = '';
        // end-tag-followed-by-start-tag omission rules
        if (htmlTag && canRemovePrecedingTag(optionalEndTag, tag)) {
          removeEndTag();
          // <colgroup> cannot be omitted if preceding </colgroup> is omitted
          // <tbody> cannot be omitted if preceding </tbody>, </thead> or </tfoot> is omitted
          optional = !isStartTagMandatory(optionalEndTag, tag);
        }
        optionalEndTag = '';
      }

      // set whitespace flags for nested tags (eg. <code> within a <pre>)
      if (options.collapseWhitespace) {
        if (!stackNoTrimWhitespace.length) {
          squashTrailingWhitespace(tag);
        }
        if (!unary) {
          if (!_canTrimWhitespace(tag, attrs) || stackNoTrimWhitespace.length) {
            stackNoTrimWhitespace.push(tag);
          }
          if (!_canCollapseWhitespace(tag, attrs) || stackNoCollapseWhitespace.length) {
            stackNoCollapseWhitespace.push(tag);
          }
        }
      }

      var openTag = '<' + tag;
      var hasUnarySlash = unarySlash && options.keepClosingSlash;

      buffer.push(openTag);

      if (options.sortAttributes) {
        options.sortAttributes(tag, attrs);
      }

      var parts = [];
      for (var i = attrs.length, isLast = true; --i >= 0;) {
        var normalized = await normalizeAttr(attrs[i], attrs, tag, options);
        if (normalized) {
          parts.unshift(buildAttr(normalized, hasUnarySlash, options, isLast, uidAttr));
          isLast = false;
        }
      }
      if (parts.length > 0) {
        buffer.push(' ');
        buffer.push.apply(buffer, parts);
      }
      // start tag must never be omitted if it has any attributes
      else if (optional && optionalStartTags(tag)) {
        optionalStartTag = tag;
      }

      buffer.push(buffer.pop() + (hasUnarySlash ? '/' : '') + '>');

      if (autoGenerated && !options.includeAutoGeneratedTags) {
        removeStartTag();
        optionalStartTag = '';
      }
    },
    end: function(tag, attrs, autoGenerated) {
      if (tag.toLowerCase() === 'svg') {
        options = Object.getPrototypeOf(options);
      }
      tag = options.name(tag);

      // check if current tag is in a whitespace stack
      if (options.collapseWhitespace) {
        if (stackNoTrimWhitespace.length) {
          if (tag === stackNoTrimWhitespace[stackNoTrimWhitespace.length - 1]) {
            stackNoTrimWhitespace.pop();
          }
        }
        else {
          squashTrailingWhitespace('/' + tag);
        }
        if (stackNoCollapseWhitespace.length &&
          tag === stackNoCollapseWhitespace[stackNoCollapseWhitespace.length - 1]) {
          stackNoCollapseWhitespace.pop();
        }
      }

      var isElementEmpty = false;
      if (tag === currentTag) {
        currentTag = '';
        isElementEmpty = !hasChars;
      }

      if (options.removeOptionalTags) {
        // <html>, <head> or <body> may be omitted if the element is empty
        if (isElementEmpty && topLevelTags(optionalStartTag)) {
          removeStartTag();
        }
        optionalStartTag = '';
        // </html> or </body> may be omitted if not followed by comment
        // </head> may be omitted if not followed by space or comment
        // </p> may be omitted if no more content in non-</a> parent
        // except for </dt> or </thead>, end tags may be omitted if no more content in parent element
        if (htmlTags(tag) && optionalEndTag && !trailingTags(optionalEndTag) && (optionalEndTag !== 'p' || !pInlineTags(tag))) {
          removeEndTag();
        }
        optionalEndTag = optionalEndTags(tag) ? tag : '';
      }

      if (options.removeEmptyElements && isElementEmpty && canRemoveElement(tag, attrs)) {
        // remove last "element" from buffer
        removeStartTag();
        optionalStartTag = '';
        optionalEndTag = '';
      }
      else {
        if (autoGenerated && !options.includeAutoGeneratedTags) {
          optionalEndTag = '';
        }
        else {
          buffer.push('</' + tag + '>');
        }
        charsPrevTag = '/' + tag;
        if (!inlineTags(tag)) {
          currentChars = '';
        }
        else if (isElementEmpty) {
          currentChars += '|';
        }
      }
    },
    chars: async function(text, prevTag, nextTag) {
      prevTag = prevTag === '' ? 'comment' : prevTag;
      nextTag = nextTag === '' ? 'comment' : nextTag;
      if (options.decodeEntities && text && !specialContentTags(currentTag)) {
        text = decode(text);
      }
      if (options.collapseWhitespace) {
        if (!stackNoTrimWhitespace.length) {
          if (prevTag === 'comment') {
            var prevComment = buffer[buffer.length - 1];
            if (prevComment.indexOf(uidIgnore) === -1) {
              if (!prevComment) {
                prevTag = charsPrevTag;
              }
              if (buffer.length > 1 && (!prevComment || !options.conservativeCollapse && / $/.test(currentChars))) {
                var charsIndex = buffer.length - 2;
                buffer[charsIndex] = buffer[charsIndex].replace(/\s+$/, function(trailingSpaces) {
                  text = trailingSpaces + text;
                  return '';
                });
              }
            }
          }
          if (prevTag) {
            if (prevTag === '/nobr' || prevTag === 'wbr') {
              if (/^\s/.test(text)) {
                var tagIndex = buffer.length - 1;
                while (tagIndex > 0 && buffer[tagIndex].lastIndexOf('<' + prevTag) !== 0) {
                  tagIndex--;
                }
                trimTrailingWhitespace(tagIndex - 1, 'br');
              }
            }
            else if (inlineTextTags(prevTag.charAt(0) === '/' ? prevTag.slice(1) : prevTag)) {
              text = collapseWhitespace(text, options, /(?:^|\s)$/.test(currentChars));
            }
          }
          if (prevTag || nextTag) {
            text = collapseWhitespaceSmart(text, prevTag, nextTag, options);
          }
          else {
            text = collapseWhitespace(text, options, true, true);
          }
          if (!text && /\s$/.test(currentChars) && prevTag && prevTag.charAt(0) === '/') {
            trimTrailingWhitespace(buffer.length - 1, nextTag);
          }
        }
        if (!stackNoCollapseWhitespace.length && nextTag !== 'html' && !(prevTag && nextTag)) {
          text = collapseWhitespace(text, options, false, false, true);
        }
      }
      if (options.processScripts && specialContentTags(currentTag)) {
        text = await processScript(text, options, currentAttrs);
      }
      if (isExecutableScript(currentTag, currentAttrs)) {
        text = await options.minifyJS(text);
      }
      if (isStyleSheet(currentTag, currentAttrs)) {
        text = options.minifyCSS(text);
      }
      if (options.removeOptionalTags && text) {
        // <html> may be omitted if first thing inside is not comment
        // <body> may be omitted if first thing inside is not space, comment, <meta>, <link>, <script>, <style> or <template>
        if (optionalStartTag === 'html' || optionalStartTag === 'body' && !/^\s/.test(text)) {
          removeStartTag();
        }
        optionalStartTag = '';
        // </html> or </body> may be omitted if not followed by comment
        // </head>, </colgroup> or </caption> may be omitted if not followed by space or comment
        if (compactTags(optionalEndTag) || looseTags(optionalEndTag) && !/^\s/.test(text)) {
          removeEndTag();
        }
        optionalEndTag = '';
      }
      charsPrevTag = /^\s*$/.test(text) ? prevTag : 'comment';
      if (options.decodeEntities && text && !specialContentTags(currentTag)) {
        // Escape any `&` symbols that start either:
        // 1) a legacy named character reference (i.e. one that doesn't end with `;`)
        // 2) or any other character reference (i.e. one that does end with `;`)
        // Note that `&` can be escaped as `&amp`, without the semi-colon.
        // https://mathiasbynens.be/notes/ambiguous-ampersands
        text = text.replace(/&((?:Iacute|aacute|uacute|plusmn|Otilde|otilde|agrave|Agrave|Yacute|yacute|Oslash|oslash|atilde|Atilde|brvbar|ccedil|Ccedil|Ograve|curren|divide|eacute|Eacute|ograve|Oacute|egrave|Egrave|Ugrave|frac12|frac14|frac34|ugrave|oacute|iacute|Ntilde|ntilde|Uacute|middot|igrave|Igrave|iquest|Aacute|cedil|laquo|micro|iexcl|Icirc|icirc|acirc|Ucirc|Ecirc|ocirc|Ocirc|ecirc|ucirc|Aring|aring|AElig|aelig|acute|pound|raquo|Acirc|times|THORN|szlig|thorn|COPY|auml|ordf|ordm|Uuml|macr|uuml|Auml|ouml|Ouml|para|nbsp|euml|quot|QUOT|Euml|yuml|cent|sect|copy|sup1|sup2|sup3|iuml|Iuml|ETH|shy|reg|not|yen|amp|AMP|REG|uml|eth|deg|gt|GT|LT|lt)(?!;)|(?:#?[0-9a-zA-Z]+;))/g, '&amp$1').replace(/</g, '<');
      }
      if (uidPattern && options.collapseWhitespace && stackNoTrimWhitespace.length) {
        text = text.replace(uidPattern, function(match, prefix, index) {
          return ignoredCustomMarkupChunks[+index][0];
        });
      }
      currentChars += text;
      if (text) {
        hasChars = true;
      }
      buffer.push(text);
    },
    comment: async function(text, nonStandard) {
      var prefix = nonStandard ? '<!' : '<!--';
      var suffix = nonStandard ? '>' : '-->';
      if (isConditionalComment(text)) {
        text = prefix + await cleanConditionalComment(text, options) + suffix;
      }
      else if (options.removeComments) {
        if (isIgnoredComment(text, options)) {
          text = '<!--' + text + '-->';
        }
        else {
          text = '';
        }
      }
      else {
        text = prefix + text + suffix;
      }
      if (options.removeOptionalTags && text) {
        // preceding comments suppress tag omissions
        optionalStartTag = '';
        optionalEndTag = '';
      }
      buffer.push(text);
    },
    doctype: function(doctype) {
      buffer.push(options.useShortDoctype ? '<!doctype' +
        (options.removeTagWhitespace ? '' : ' ') + 'html>' :
        collapseWhitespaceAll(doctype));
    }
  });

  await parser.parse();

  if (options.removeOptionalTags) {
    // <html> may be omitted if first thing inside is not comment
    // <head> or <body> may be omitted if empty
    if (topLevelTags(optionalStartTag)) {
      removeStartTag();
    }
    // except for </dt> or </thead>, end tags may be omitted if no more content in parent element
    if (optionalEndTag && !trailingTags(optionalEndTag)) {
      removeEndTag();
    }
  }
  if (options.collapseWhitespace) {
    squashTrailingWhitespace('br');
  }

  return joinResultSegments(buffer, options, uidPattern ? function(str) {
    return str.replace(uidPattern, function(match, prefix, index, suffix) {
      var chunk = ignoredCustomMarkupChunks[+index][0];
      if (options.collapseWhitespace) {
        if (prefix !== '\t') {
          chunk = prefix + chunk;
        }
        if (suffix !== '\t') {
          chunk += suffix;
        }
        return collapseWhitespace(chunk, {
          preserveLineBreaks: options.preserveLineBreaks,
          conservativeCollapse: !options.trimCustomFragments
        }, /^[ \n\r\t\f]/.test(chunk), /[ \n\r\t\f]$/.test(chunk));
      }
      return chunk;
    });
  } : identity, uidIgnore ? function(str) {
    return str.replace(new RegExp('<!--' + uidIgnore + '([0-9]+)-->', 'g'), function(match, index) {
      return ignoredMarkupChunks[+index];
    });
  } : identity);
}

function joinResultSegments(results, options, restoreCustom, restoreIgnore) {
  var str;
  var maxLineLength = options.maxLineLength;
  var noNewlinesBeforeTagClose = options.noNewlinesBeforeTagClose;

  if (maxLineLength) {
    var line = '', lines = [];
    while (results.length) {
      var len = line.length;
      var end = results[0].indexOf('\n');
      var isClosingTag = Boolean(results[0].match(endTag));
      var shouldKeepSameLine = noNewlinesBeforeTagClose && isClosingTag;
      if (end < 0) {
        line += restoreIgnore(restoreCustom(results.shift()));
      }
      else {
        line += restoreIgnore(restoreCustom(results[0].slice(0, end)));
        results[0] = results[0].slice(end + 1);
      }
      if (len > 0 && line.length > maxLineLength && !shouldKeepSameLine) {
        lines.push(line.slice(0, len));
        line = line.slice(len);
      }
      else if (end >= 0) {
        lines.push(line);
        line = '';
      }
    }
    if (line) {
      lines.push(line);
    }
    str = lines.join('\n');
  }
  else {
    str = restoreIgnore(restoreCustom(results.join('')));
  }
  return options.collapseWhitespace ? collapseWhitespace(str, options, true, true) : str;
}

exports.minify = async function(value, options) {
  var start = Date.now();
  options = processOptions(options || {});
  var result = await minify(value, options);
  options.log('minified in: ' + (Date.now() - start) + 'ms');
  return result;
};


code:
'use strict';

function Sorter() {
}

Sorter.prototype.sort = function(tokens, fromIndex) {
  fromIndex = fromIndex || 0;
  for (var i = 0, len = this.keys.length; i < len; i++) {
    var key = this.keys[i];
    var token = key.slice(1);
    var index = tokens.indexOf(token, fromIndex);
    if (index !== -1) {
      do {
        if (index !== fromIndex) {
          tokens.splice(index, 1);
          tokens.splice(fromIndex, 0, token);
        }
        fromIndex++;
      } while ((index = tokens.indexOf(token, fromIndex)) !== -1);
      return this[key].sort(tokens, fromIndex);
    }
  }
  return tokens;
};

function TokenChain() {
}

TokenChain.prototype = {
  add: function(tokens) {
    var self = this;
    tokens.forEach(function(token) {
      var key = '$' + token;
      if (!self[key]) {
        self[key] = [];
        self[key].processed = 0;
      }
      self[key].push(tokens);
    });
  },
  createSorter: function() {
    var self = this;
    var sorter = new Sorter();
    sorter.keys = Object.keys(self).sort(function(j, k) {
      var m = self[j].length;
      var n = self[k].length;
      return m < n ? 1 : m > n ? -1 : j < k ? -1 : j > k ? 1 : 0;
    }).filter(function(key) {
      if (self[key].processed < self[key].length) {
        var token = key.slice(1);
        var chain = new TokenChain();
        self[key].forEach(function(tokens) {
          var index;
          while ((index = tokens.indexOf(token)) !== -1) {
            tokens.splice(index, 1);
          }
          tokens.forEach(function(token) {
            self['$' + token].processed++;
          });
          chain.add(tokens.slice(0));
        });
        sorter[key] = chain.createSorter();
        return true;
      }
      return false;
    });
    return sorter;
  }
};

module.exports = TokenChain;

license: mit


code:
'use strict';

function createMap(values, ignoreCase) {
  var map = {};
  values.forEach(function(value) {
    map[value] = 1;
  });
  return ignoreCase ? function(value) {
    return map[value.toLowerCase()] === 1;
  } : function(value) {
    return map[value] === 1;
  };
}

async function replaceAsync(str, regex, asyncFn) {
  const promises = [];
  str.replace(regex, (match, ...args) => {
    const promise = asyncFn(match, ...args);
    promises.push(promise);
  });
  const data = await Promise.all(promises);
  return str.replace(regex, () => data.shift());
}

exports.createMap = createMap;
exports.createMapFromString = function(values, ignoreCase) {
  return createMap(values.split(/,/), ignoreCase);
};

exports.replaceAsync = replaceAsync;


code: area base br col embed hr img input link menuitem meta param source track wbr


code: a abbr address area article aside audio b base bdi bdo blockquote body br button canvas caption cite code col colgroup data datalist dd del details dfn dialog div dl dt em embed fieldset figcaption figure footer form h1 h2 h3 h4 h5 h6 head header hgroup hr html i iframe img input ins kbd label legend li link main map mark math menu menuitem meta meter nav noscript object ol optgroup option output p param picture pre progress q rb rp rt rtc ruby s samp script search section select slot small source span strong style sub summary sup svg table tbody td template textarea tfoot th thead time title tr track u ul var video wbr


code:
declare namespace htmlTags {
	export type htmlTags =
		| 'a'
		| 'abbr'
		| 'address'
		| 'area'
		| 'article'
		| 'aside'
		| 'audio'
		| 'b'
		| 'base'
		| 'bdi'
		| 'bdo'
		| 'blockquote'
		| 'body'
		| 'br'
		| 'button'
		| 'canvas'
		| 'caption'
		| 'cite'
		| 'code'
		| 'col'
		| 'colgroup'
		| 'data'
		| 'datalist'
		| 'dd'
		| 'del'
		| 'details'
		| 'dfn'
		| 'dialog'
		| 'div'
		| 'dl'
		| 'dt'
		| 'em'
		| 'embed'
		| 'fieldset'
		| 'figcaption'
		| 'figure'
		| 'footer'
		| 'form'
		| 'h1'
		| 'h2'
		| 'h3'
		| 'h4'
		| 'h5'
		| 'h6'
		| 'head'
		| 'header'
		| 'hgroup'
		| 'hr'
		| 'html'
		| 'i'
		| 'iframe'
		| 'img'
		| 'input'
		| 'ins'
		| 'kbd'
		| 'label'
		| 'legend'
		| 'li'
		| 'link'
		| 'main'
		| 'map'
		| 'mark'
		| 'math'
		| 'menu'
		| 'menuitem'
		| 'meta'
		| 'meter'
		| 'nav'
		| 'noscript'
		| 'object'
		| 'ol'
		| 'optgroup'
		| 'option'
		| 'output'
		| 'p'
		| 'param'
		| 'picture'
		| 'pre'
		| 'progress'
		| 'q'
		| 'rb'
		| 'rp'
		| 'rt'
		| 'rtc'
		| 'ruby'
		| 's'
		| 'samp'
		| 'script'
		| 'search'
		| 'section'
		| 'select'
		| 'slot'
		| 'small'
		| 'source'
		| 'span'
		| 'strong'
		| 'style'
		| 'sub'
		| 'summary'
		| 'sup'
		| 'svg'
		| 'table'
		| 'tbody'
		| 'td'
		| 'template'
		| 'textarea'
		| 'tfoot'
		| 'th'
		| 'thead'
		| 'time'
		| 'title'
		| 'tr'
		| 'track'
		| 'u'
		| 'ul'
		| 'var'
		| 'video'
		| 'wbr'
}

/**
List of standard HTML tags.

@example
```
import htmlTags = require('html-tags');

console.log(htmlTags);
//=> ['a', 'abbr', 'acronym', …]
```
*/
declare const htmlTags: readonly htmlTags.htmlTags[];

export = htmlTags;


code:
'use strict';
module.exports = require('./html-tags.json');


html-tags

description: List of standard HTML tags

license: MIT

repository: sindresorhus/html-tags

test: xo && ava && tsd

keywords: html html5 tags elements list whatwg w3c void self-closing

import/extensions: off


code:
# html-tags

> List of standard HTML tags

It's just a couple of JSON files that can be used in any environment.

It intentionally leaves out obsolete tags.

## Install

```
$ npm install html-tags
```

## Usage

```js
const htmlTags = require('html-tags');

console.log(htmlTags);
//=> ['a', 'abbr', 'acronym', …]
```

And void (self-closing) tags:

```js
const voidHtmlTags = require('html-tags/void');

console.log(voidHtmlTags);
//=> ['area', 'base', 'br', …]
```

## Contribute

Make sure to update types in `index.d.ts` when changing HTML elements.


code:
declare namespace htmlTagsVoid {
	export type htmlTagsVoid =
		| 'area'
		| 'base'
		| 'br'
		| 'col'
		| 'embed'
		| 'hr'
		| 'img'
		| 'input'
		| 'link'
		| 'menuitem'
		| 'meta'
		| 'param'
		| 'source'
		| 'track'
		| 'wbr'
}

/**
List of standard, self-closing HTML tags.

@example
```
import htmlTags = require('html-tags/void');

console.log(htmlTags);
//=> ['a', 'abbr', 'acronym' …]
```
*/
declare const htmlTagsVoid: readonly htmlTagsVoid.htmlTagsVoid[];

export = htmlTagsVoid;


code:
'use strict';
module.exports = require('./html-tags-void.json');


code:
[![npm][npm]][npm-url]
[![node][node]][node-url]
![npm](https://img.shields.io/npm/dw/html-webpack-plugin.svg)
[![tests][tests]][tests-url]
[![Backers on Open Collective](https://opencollective.com/html-webpack-plugin/backers/badge.svg)](#backers)
 [![Sponsors on Open Collective](https://opencollective.com/html-webpack-plugin/sponsors/badge.svg)](#sponsors)

HTML Webpack Plugin

Plugin that simplifies creation of HTML files to serve your bundles

Install

Webpack 5

```bash
  npm i --save-dev html-webpack-plugin
```

```bash
  yarn add --dev html-webpack-plugin
```

Webpack 4

```bash
  npm i --save-dev html-webpack-plugin@4
```

```bash
  yarn add --dev html-webpack-plugin@4
```

This is a [webpack](http://webpack.js.org/) plugin that simplifies creation of HTML files to serve your `webpack` bundles. This is especially useful for `webpack` bundles that include a hash in the filename which changes every compilation. You can either let the plugin generate an HTML file for you, supply
your own template using `lodash` templates or use your own loader.

Sponsors

Thanks for supporting the ongoing improvements to the html-webpack-plugin!

Zero Config

The `html-webpack-plugin` works without configuration.
It's a great addition to the [⚙ webpack-config-plugins](https://github.com/namics/webpack-config-plugins/blob/master/README.md#zero-config-webpack-dev-server-example).

Plugins

The `html-webpack-plugin` provides [hooks](https://github.com/jantimon/html-webpack-plugin#events) to extend it to your needs. There are already some really powerful plugins which can be integrated with zero configuration

 * [webpack-subresource-integrity](https://www.npmjs.com/package/webpack-subresource-integrity) for enhanced asset security
 * [appcache-webpack-plugin](https://github.com/lettertwo/appcache-webpack-plugin) for iOS and Android offline usage
 * [favicons-webpack-plugin](https://github.com/jantimon/favicons-webpack-plugin) which generates favicons and icons for iOS, Android and desktop browsers
 * [html-webpack-harddisk-plugin](https://github.com/jantimon/html-webpack-harddisk-plugin) can be used to always write to disk the html file, useful when webpack-dev-server / HMR are being used
 * [html-webpack-inline-svg-plugin](https://github.com/thegc/html-webpack-inline-svg-plugin) to inline SVGs in the resulting HTML file.
 * [html-webpack-exclude-assets-plugin](https://github.com/jamesjieye/html-webpack-exclude-assets-plugin) for excluding assets using regular expressions
 * [html-webpack-include-assets-plugin](https://github.com/jharris4/html-webpack-include-assets-plugin) for including lists of js or css file paths (such as those copied by the copy-webpack-plugin).
 * [html-webpack-injector](https://github.com/thearchitgarg/html-webpack-injector) to inject chunks in `head` or `body` (different locations ) of same html document.
 * [resource-hints-webpack-plugin](https://github.com/jantimon/resource-hints-webpack-plugin) to add resource hints for faster initial page loads using `<link rel='preload'>` and `<link rel='prefetch'>`
 * [link-media-html-webpack-plugin](https://github.com/yaycmyk/link-media-html-webpack-plugin) allows for injected stylesheet `<link />` tags to have their media attribute set automatically; useful for providing specific desktop/mobile/print etc. stylesheets that the browser will conditionally download
 * [html-webpack-inline-style-plugin](https://github.com/djaax/html-webpack-inline-style-plugin) for inlining styles to HTML elements using [juice](https://github.com/Automattic/juice). Useful for email generation automatisation.
 * [html-webpack-exclude-empty-assets-plugin](https://github.com/KnisterPeter/html-webpack-exclude-empty-assets-plugin) removes empty assets from being added to the html. This fixes some problems with extract-text-plugin with webpack 4.
 * [webpack-concat-plugin](https://github.com/hxlniada/webpack-concat-plugin) for concat and uglify files that needn't to be webpack bundles(for legacy files) and inject to html-webpack-plugin.
 * [html-webpack-link-type-plugin](https://github.com/steadyapp/html-webpack-link-type-plugin) adds a configurable mimetype to resources injected as links (such as adding type="text/css" to external stylesheets) for compatibility with "strict mode".
 * [csp-html-webpack-plugin](https://github.com/slackhq/csp-html-webpack-plugin) to add [Content Security Policy](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy) meta tags to the HTML output
 * [strict-csp-html-webpack-plugin](https://github.com/google/strict-csp/tree/main/strict-csp-html-webpack-plugin) to add a [**strict** Content-Security-Policy (CSP)](https://web.dev) as a `meta` tag to the HTML output. A strict CSP is specifically efficient against XSS attacks.
 * [webpack-nomodule-plugin](https://github.com/swimmadude66/webpack-nomodule-plugin) allows you to add a `nomodule` attribute to specific injected scripts, which prevents the scripts from being loaded by newer browsers. Good for limiting loads of polyfills.
  * [html-webpack-skip-assets-plugin](https://github.com/swimmadude66/html-webpack-skip-assets-plugin) Skip adding certain output files to the html file. Built as a drop-in replacement for [html-webpack-exclude-assets-plugin](https://www.npmjs.com/package/html-webpack-exclude-assets-plugin) and works with newer [html-webpack-plugin](https://github.com/jantimon/html-webpack-plugin) versions
 * [html-webpack-inject-preload](https://github.com/principalstudio/html-webpack-inject-preload) allows to add preload links <link rel='preload'> anywhere you want.
 * [inject-body-webpack-plugin](https://github.com/Jaid/inject-body-webpack-plugin) is a simple method of injecting a custom HTML string into the body.
 * [html-webpack-plugin-django](https://github.com/TommasoAmici/html-webpack-plugin-django) a Webpack plugin to inject Django static tags.
 * [html-webpack-inject-attributes-plugin](https://github.com/dyw934854565/html-webpack-inject-attributes-plugin) add extra attributes to inject assetTags.
 * [js-entry-webpack-plugin](https://github.com/liam61/html-webpack-plugin) creates webpack bundles into your js entry

Usage

The plugin will generate an HTML5 file for you that includes all your `webpack`
bundles in the head using `script` tags. Just add the plugin to your `webpack`
config as follows:

**webpack.config.js**
```js
const HtmlWebpackPlugin = require('html-webpack-plugin')

module.exports = {
  entry: 'index.js',
  output: {
    path: __dirname + '/dist',
    filename: 'index_bundle.js'
  },
  plugins: [
    new HtmlWebpackPlugin()
  ]
}
```

This will generate a file `dist/index.html` containing the following

```html
<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>Webpack App</title>
    <script defer src="index_bundle.js"></script>
  </head>
  <body>
  </body>
</html>
```

If you have multiple `webpack` entry points, they will all be included with `script` tags in the generated HTML.

If you have any CSS assets in webpack's output (for example, CSS extracted with the [mini-css-extract-plugin](https://github.com/webpack-contrib/mini-css-extract-plugin))
then these will be included with `<link>` tags in the HTML head.

If you have plugins that make use of it, `html-webpack-plugin` should be ordered first before any of the integrated Plugins.

Options

You can pass a hash of configuration options to `html-webpack-plugin`.
Allowed values are as follows:

|Name|Type|Default|Description|
|:--:|:--:|:-----:|:----------|
|**`title`**|`{String}`|`Webpack App`|The title to use for the generated HTML document|
|**`filename`**|`{String\|Function}`|`'index.html'`|The file to write the HTML to. Defaults to `index.html`. You can specify a subdirectory here too (eg: `assets/admin.html`). The `[name]` placeholder will be replaced with the entry name. Can also be a function e.g. `(entryName) => entryName + '.html'`. |
|**`template`**|`{String}`|``|`webpack` relative or absolute path to the template. By default it will use `src/index.ejs` if it exists. Please see the [docs](https://github.com/jantimon/html-webpack-plugin/blob/master/docs/template-option.md) for details|
|**`templateContent`**|`{string\|Function\|false}`|false| Can be used instead of `template` to provide an inline template - please read the [Writing Your Own Templates](https://github.com/jantimon/html-webpack-plugin#writing-your-own-templates) section |
|**`templateParameters`**|`{Boolean\|Object\|Function}`| `false`| Allows to overwrite the parameters used in the template - see [example](https://github.com/jantimon/html-webpack-plugin/tree/master/examples/template-parameters) |
|**`inject`**|`{Boolean\|String}`|`true`|`true \|\| 'head' \|\| 'body' \|\| false` Inject all assets into the given `template` or `templateContent`. When passing `'body'` all javascript resources will be placed at the bottom of the body element. `'head'` will place the scripts in the head element. Passing `true` will add it to the head/body depending on the `scriptLoading` option. Passing `false` will disable automatic injections. - see the [inject:false example](https://github.com/jantimon/html-webpack-plugin/tree/master/examples/custom-insertion-position)|
|**`publicPath`**|`{String\|'auto'}`|`'auto'`|The publicPath used for script and link tags|
|**`scriptLoading`**|`{'blocking'\|'defer'\|'module'\|'systemjs-module'}`|`'defer'`| Modern browsers support non blocking javascript loading (`'defer'`) to improve the page startup performance. Setting to `'module'` adds attribute [`type="module"`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules#applying_the_module_to_your_html). This also implies "defer", since modules are automatically deferred. |
|**`favicon`**|`{String}`|``|Adds the given favicon path to the output HTML|
|**`meta`**|`{Object}`|`{}`|Allows to inject `meta`-tags. E.g. `meta: {viewport: 'width=device-width, initial-scale=1, shrink-to-fit=no'}`|
|**`base`**|`{Object\|String\|false}`|`false`|Inject a [`base`](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/base) tag. E.g. `base: "https://example.com/path/page.html`|
|**`minify`**|`{Boolean\|Object}`|`true` if `mode` is `'production'`, otherwise `false`|Controls if and in what ways the output should be minified. See [minification](#minification) below for more details.|
|**`hash`**|`{Boolean}`|`false`|If `true` then append a unique `webpack` compilation hash to all included scripts and CSS files (i.e. `main.js?hash=compilation_hash`). This is useful for cache busting|
|**`cache`**|`{Boolean}`|`true`|Emit the file only if it was changed|
|**`showErrors`**|`{Boolean}`|`true`|Errors details will be written into the HTML page|
|**`chunks`**|`{?}`|`?`|Allows you to add only some chunks (e.g only the unit-test chunk)|
|**`chunksSortMode`**|`{String\|Function}`|`auto`|Allows to control how chunks should be sorted before they are included to the HTML. Allowed values are `'none' \| 'auto' \| 'manual' \| {Function}`|
|**`excludeChunks`**|`{Array.<string>}`|``|Allows you to skip some chunks (e.g don't add the unit-test chunk)|
|**`xhtml`**|`{Boolean}`|`false`|If `true` render the `link` tags as self-closing (XHTML compliant)|

Here's an example webpack config illustrating how to use these options

**webpack.config.js**
```js
{
  entry: 'index.js',
  output: {
    path: __dirname + '/dist',
    filename: 'index_bundle.js'
  },
  plugins: [
    new HtmlWebpackPlugin({
      title: 'My App',
      filename: 'assets/admin.html'
    })
  ]
}
```

### Generating Multiple HTML Files

To generate more than one HTML file, declare the plugin more than
once in your plugins array

**webpack.config.js**
```js
{
  entry: 'index.js',
  output: {
    path: __dirname + '/dist',
    filename: 'index_bundle.js'
  },
  plugins: [
    new HtmlWebpackPlugin(), // Generates default index.html
    new HtmlWebpackPlugin({  // Also generate a test.html
      filename: 'test.html',
      template: 'src/assets/test.html'
    })
  ]
}
```

### Writing Your Own Templates

If the default generated HTML doesn't meet your needs you can supply
your own template. The easiest way is to use the `template` option and pass a custom HTML file.
The html-webpack-plugin will automatically inject all necessary CSS, JS, manifest
and favicon files into the markup.

Details of other template loaders are [documented here](https://github.com/jantimon/html-webpack-plugin/blob/master/docs/template-option.md).

```js
plugins: [
  new HtmlWebpackPlugin({
    title: 'Custom template',
    // Load a custom template (lodash by default)
    template: 'index.html'
  })
]
```

**index.html**
```html
<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8"/>
    <title><%= htmlWebpackPlugin.options.title %></title>
  </head>
  <body>
  </body>
</html>
```

If you already have a template loader, you can use it to parse the template.
Please note that this will also happen if you specify the html-loader and use `.html` file as template.

**webpack.config.js**
```js
module: {
  loaders: [
    { test: /\.hbs$/, loader: "handlebars-loader" }
  ]
},
plugins: [
  new HtmlWebpackPlugin({
    title: 'Custom template using Handlebars',
    template: 'index.hbs'
  })
]
```

You can use the `lodash` syntax out of the box. If the `inject` feature doesn't fit your needs and you want full control over the asset placement use the [default template](https://github.com/jaketrent/html-webpack-template/blob/86f285d5c790a6c15263f5cc50fd666d51f974fd/index.html) of the [html-webpack-template project](https://github.com/jaketrent/html-webpack-template) as a starting point for writing your own.

The following variables are available in the template by default (you can extend them using the `templateParameters` option):

- `htmlWebpackPlugin`: data specific to this plugin

  - `htmlWebpackPlugin.options`: the options hash that was passed to
     the plugin. In addition to the options actually used by this plugin,
     you can use this hash to pass arbitrary data through to your template.

  - `htmlWebpackPlugin.tags`: the prepared `headTags` and `bodyTags` Array to render the `<base>`, `<meta>`, `<script>` and `<link>` tags.
     Can be used directly in templates and literals. For example:
     ```html
     <html>
       <head>
         <%= htmlWebpackPlugin.tags.headTags %>
       </head>
       <body>
         <%= htmlWebpackPlugin.tags.bodyTags %>
       </body>
     </html>
     ```

  - `htmlWebpackPlugin.files`: direct access to the files used during the compilation.

    ```typescript
    publicPath: string;
    js: string[];
    css: string[];
    manifest?: string;
    favicon?: string;
    ```

- `webpackConfig`: the webpack configuration that was used for this compilation. This
  can be used, for example, to get the `publicPath` (`webpackConfig.output.publicPath`).

- `compilation`: the webpack [compilation object](https://webpack.js.org/api/compilation-object/).
  This can be used, for example, to get the contents of processed assets and inline them
  directly in the page, through `compilation.assets[...].source()`
  (see [the inline template example](examples/inline/template.pug)).

The template can also be directly inlined directly into the options object.
⚠ **`templateContent` does not allow to use webpack loaders for your template and will not watch for template file changes**

**webpack.config.js**
```js
new HtmlWebpackPlugin({
  templateContent: `
    <html>
      <body>
        <h1>Hello World</h1>
      </body>
    </html>
  `
})
```

The `templateContent` can also access all `templateParameters` values.
⚠ **`templateContent` does not allow to use webpack loaders for your template and will not watch for template file changes**

**webpack.config.js**
```js
new HtmlWebpackPlugin({
  inject: false,
  templateContent: ({htmlWebpackPlugin}) => `
    <html>
      <head>
        ${htmlWebpackPlugin.tags.headTags}
      </head>
      <body>
        <h1>Hello World</h1>
        ${htmlWebpackPlugin.tags.bodyTags}
      </body>
    </html>
  `
})
```

### Filtering Chunks

To include only certain chunks you can limit the chunks being used

**webpack.config.js**
```js
plugins: [
  new HtmlWebpackPlugin({
    chunks: ['app']
  })
]
```

It is also possible to exclude certain chunks by setting the `excludeChunks` option

**webpack.config.js**
```js
plugins: [
  new HtmlWebpackPlugin({
    excludeChunks: [ 'dev-helper' ]
  })
]
```

### Minification

If the `minify` option is set to `true` (the default when webpack's `mode` is `'production'`),
the generated HTML will be minified using [html-minifier-terser](https://github.com/DanielRuf/html-minifier-terser)
and the following options:

```js
{
  collapseWhitespace: true,
  keepClosingSlash: true,
  removeComments: true,
  removeRedundantAttributes: true,
  removeScriptTypeAttributes: true,
  removeStyleLinkTypeAttributes: true,
  useShortDoctype: true
}
```

To use custom [html-minifier options](https://github.com/DanielRuf/html-minifier-terser#options-quick-reference)
pass an object to `minify` instead. This object will not be merged with the defaults above.

To disable minification during production mode set the `minify` option to `false`.

### Meta Tags

If the `meta` option is set the html-webpack-plugin will inject meta tags.
For the default template the html-webpack-plugin will already provide a default for the `viewport` meta tag.

Please take a look at this well maintained list of almost all [possible meta tags](https://github.com/joshbuchea/HEAD#meta).

#### name/content meta tags

Most meta tags are configured by setting a `name` and a `content` attribute.
To add those use a key/value pair:

**webpack.config.js**
```js
plugins: [
  new HtmlWebpackPlugin({
      'meta': {
        'viewport': 'width=device-width, initial-scale=1, shrink-to-fit=no',
        // Will generate: <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
        'theme-color': '#4285f4'
        // Will generate: <meta name="theme-color" content="#4285f4">
      }
  })
]
```

#### Simulate http response headers

The **http-equiv** attribute is essentially used to simulate a HTTP response header.
This format is supported using an object notation which allows you to add any attribute:

**webpack.config.js**
```js
plugins: [
  new HtmlWebpackPlugin({
    'meta': {
      'Content-Security-Policy': { 'http-equiv': 'Content-Security-Policy', 'content': 'default-src https:' },
      // Will generate: <meta http-equiv="Content-Security-Policy" content="default-src https:">
      // Which equals to the following http header: `Content-Security-Policy: default-src https:`
      'set-cookie': { 'http-equiv': 'set-cookie', content: 'name=value; expires=date; path=url' },
      // Will generate: <meta http-equiv="set-cookie" content="value; expires=date; path=url">
      // Which equals to the following http header: `set-cookie: value; expires=date; path=url`
    }
  })
]
```

### Base Tag

When the `base` option is used,
html-webpack-plugin will inject a [base tag](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/base).
By default, a base tag will not be injected.

The following two are identical and will both insert `<base href="http://example.com/some/page.html">`:

```js
new HtmlWebpackPlugin({
  'base': 'http://example.com/some/page.html'
})
```

```js
new HtmlWebpackPlugin({
  'base': { 'href': 'http://example.com/some/page.html' }
})
```

The `target` can be specified with the corresponding key:

```js
new HtmlWebpackPlugin({
  'base': {
    'href': 'http://example.com/some/page.html',
    'target': '_blank'
  }
})
```

which will inject the element `<base href="http://example.com/some/page.html" target="_blank">`.

### Long Term Caching

For long term caching add `contenthash` to the filename.

**Example:**

```js
plugins: [
  new HtmlWebpackPlugin({
    filename: 'index.[contenthash].html'
  })
]
```

`contenthash` is the hash of the content of the output file.

Refer webpack's [Template Strings](https://webpack.js.org/configuration/output/#template-strings) for more details

### Events

To allow other [plugins](https://github.com/webpack/docs/wiki/plugins) to alter the HTML this plugin executes
[tapable](https://github.com/webpack/tapable/tree/master) hooks.

The [lib/hooks.js](https://github.com/jantimon/html-webpack-plugin/blob/master/lib/hooks.js) contains all information
about which values are passed.

[![Concept flow uml](https://raw.githubusercontent.com/jantimon/html-webpack-plugin/master/flow.png)](https://github.com/jantimon/html-webpack-plugin/blob/master/flow.puml)

#### `beforeAssetTagGeneration` hook

```
    AsyncSeriesWaterfallHook<{
      assets: {
        publicPath: string,
        js: Array<{string}>,
        css: Array<{string}>,
        favicon?: string | undefined,
        manifest?: string | undefined
      },
      outputName: string,
      plugin: HtmlWebpackPlugin
    }>
```

#### `alterAssetTags` hook

```
    AsyncSeriesWaterfallHook<{
      assetTags: {
        scripts: Array<HtmlTagObject>,
        styles: Array<HtmlTagObject>,
        meta: Array<HtmlTagObject>,
      },
      publicPath: string,
      outputName: string,
      plugin: HtmlWebpackPlugin
    }>
```

#### `alterAssetTagGroups` hook

```
    AsyncSeriesWaterfallHook<{
      headTags: Array<HtmlTagObject | HtmlTagObject>,
      bodyTags: Array<HtmlTagObject | HtmlTagObject>,
      publicPath: string,
      outputName: string,
      plugin: HtmlWebpackPlugin
    }>
```

#### `afterTemplateExecution` hook

```
    AsyncSeriesWaterfallHook<{
      html: string,
      headTags: Array<HtmlTagObject | HtmlTagObject>,
      bodyTags: Array<HtmlTagObject | HtmlTagObject>,
      outputName: string,
      plugin: HtmlWebpackPlugin,
    }>
```

#### `beforeEmit` hook

```
    AsyncSeriesWaterfallHook<{
      html: string,
      outputName: string,
      plugin: HtmlWebpackPlugin,
    }>
```

#### `afterEmit` hook

```
    AsyncSeriesWaterfallHook<{
      outputName: string,
      plugin: HtmlWebpackPlugin
    }>
```

Example implementation: [webpack-subresource-integrity](https://www.npmjs.com/package/webpack-subresource-integrity)

**plugin.js**
```js
// If your plugin is direct dependent to the html webpack plugin:
const HtmlWebpackPlugin = require('html-webpack-plugin');
// If your plugin is using html-webpack-plugin as an optional dependency
// you can use https://github.com/tallesl/node-safe-require instead:
const HtmlWebpackPlugin = require('safe-require')('html-webpack-plugin');

class MyPlugin {
  apply (compiler) {
    compiler.hooks.compilation.tap('MyPlugin', (compilation) => {
      console.log('The compiler is starting a new compilation...')

      // Static Plugin interface |compilation |HOOK NAME | register listener
      HtmlWebpackPlugin.getHooks(compilation).beforeEmit.tapAsync(
        'MyPlugin', // <-- Set a meaningful name here for stacktraces
        (data, cb) => {
          // Manipulate the content
          data.html += 'The Magic Footer'
          // Tell webpack to move on
          cb(null, data)
        }
      )
    })
  }
}

module.exports = MyPlugin
```

**webpack.config.js**
```js
plugins: [
  new MyPlugin({ options: '' })
]
```

Note that the callback must be passed the HtmlWebpackPluginData in order to pass this onto any other plugins listening on the same `beforeEmit` event

Maintainers

        Jan Nicklas

        Thomas Sileghem

## Backers

Thank you to all our backers!
If you want to support the project as well [become a sponsor](https://opencollective.com/html-webpack-plugin#sponsor) or a [a backer](https://opencollective.com/html-webpack-plugin#backer).

## Contributors

This project exists thanks to all the people who contribute.

You're free to contribute to this project by submitting [issues](https://github.com/jantimon/html-webpack-plugin/issues) and/or [pull requests](https://github.com/jantimon/html-webpack-plugin/pulls). This project is test-driven, so keep in mind that every change and new feature should be covered by tests.

This project uses the [semistandard code style](https://github.com/Flet/semistandard).

[npm]: https://img.shields.io/npm/v/html-webpack-plugin.svg
[npm-url]: https://npmjs.com/package/html-webpack-plugin

[node]: https://img.shields.io/node/v/html-webpack-plugin.svg
[node-url]: https://nodejs.org

[tests]: https://github.com/jantimon/html-webpack-plugin/workflows/CI/badge.svg
[tests-url]: https://github.com/jantimon/html-webpack-plugin/actions?query=workflow%3ACI


code:
<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title><%= htmlWebpackPlugin.options.title %></title>
  </head>
  <body>
  </body>
</html>