react-scripts/node_modules/html-minifier/src/htmllint.js

Configuration and scripts for Create React App.

/*!
 * HTMLLint (to be used in conjunction with HTMLMinifier)
 *
 * Copyright (c) 2010-2016 Juriy "kangax" Zaytsev
 * Licensed under the MIT license.
 *
 */

'use strict';

function isPresentationalElement(tag) {
  return /^(?:big|small|hr|blink|marquee)$/.test(tag);
}
function isDeprecatedElement(tag) {
  return /^(?:applet|basefont|center|dir|font|isindex|strike)$/.test(tag);
}
function isEventAttribute(attrName) {
  return /^on[a-z]+/.test(attrName);
}
function isStyleAttribute(attrName) {
  return attrName.toLowerCase() === 'style';
}
function isDeprecatedAttribute(tag, attrName) {
  return (
    attrName === 'align' &&
    /^(?:caption|applet|iframe|img|imput|object|legend|table|hr|div|h[1-6]|p)$/.test(tag) ||
    attrName === 'alink' && tag === 'body' ||
    attrName === 'alt' && tag === 'applet' ||
    attrName === 'archive' && tag === 'applet' ||
    attrName === 'background' && tag === 'body' ||
    attrName === 'bgcolor' && /^(?:table|t[rdh]|body)$/.test(tag) ||
    attrName === 'border' && /^(?:img|object)$/.test(tag) ||
    attrName === 'clear' && tag === 'br' ||
    attrName === 'code' && tag === 'applet' ||
    attrName === 'codebase' && tag === 'applet' ||
    attrName === 'color' && /^(?:base(?:font)?)$/.test(tag) ||
    attrName === 'compact' && /^(?:dir|[dou]l|menu)$/.test(tag) ||
    attrName === 'face' && /^base(?:font)?$/.test(tag) ||
    attrName === 'height' && /^(?:t[dh]|applet)$/.test(tag) ||
    attrName === 'hspace' && /^(?:applet|img|object)$/.test(tag) ||
    attrName === 'language' && tag === 'script' ||
    attrName === 'link' && tag === 'body' ||
    attrName === 'name' && tag === 'applet' ||
    attrName === 'noshade' && tag === 'hr' ||
    attrName === 'nowrap' && /^t[dh]$/.test(tag) ||
    attrName === 'object' && tag === 'applet' ||
    attrName === 'prompt' && tag === 'isindex' ||
    attrName === 'size' && /^(?:hr|font|basefont)$/.test(tag) ||
    attrName === 'start' && tag === 'ol' ||
    attrName === 'text' && tag === 'body' ||
    attrName === 'type' && /^(?:li|ol|ul)$/.test(tag) ||
    attrName === 'value' && tag === 'li' ||
    attrName === 'version' && tag === 'html' ||
    attrName === 'vlink' && tag === 'body' ||
    attrName === 'vspace' && /^(?:applet|img|object)$/.test(tag) ||
    attrName === 'width' && /^(?:hr|td|th|applet|pre)$/.test(tag)
  );
}
function isInaccessibleAttribute(attrName, attrValue) {
  return attrName === 'href' && /^\s*javascript\s*:\s*void\s*(\s+0|\(\s*0\s*\))\s*$/i.test(attrValue);
}

function Lint() {
  this.log = [];
  this._lastElement = null;
  this._isElementRepeated = false;
}

Lint.prototype.testElement = function(tag) {
  this._attributes = Object.create(null);
  if (isDeprecatedElement(tag)) {
    this.log.push(
      'Found <span class="deprecated-element">deprecated</span> <strong><code>&lt;' +
        tag + '&gt;</code></strong> element'
    );
  }
  else if (isPresentationalElement(tag)) {
    this.log.push(
      'Found <span class="presentational-element">presentational</span> <strong><code>&lt;' +
        tag + '&gt;</code></strong> element'
    );
  }
  else {
    this.checkRepeatingElement(tag);
  }
};

Lint.prototype.checkRepeatingElement = function(tag) {
  if (tag === 'br' && this._lastElement === 'br') {
    this._isElementRepeated = true;
  }
  else if (this._isElementRepeated) {
    this._reportRepeatingElement();
    this._isElementRepeated = false;
  }
  this._lastElement = tag;
};

Lint.prototype._reportRepeatingElement = function() {
  this.log.push('Found <code>&lt;br></code> sequence. Try replacing it with styling.');
};

Lint.prototype.testAttribute = function(tag, attrName, attrValue) {
  if (this._attributes[attrName]) {
    this.log.push(
      'Found <span class="repeating-attribute">repeating attribute</span> (<strong>' +
      attrName + '</strong>) on <strong><code>&lt;' + tag + '&gt;</code></strong> element.'
    );
  }
  else {
    this._attributes[attrName] = true;
  }
  if (isEventAttribute(attrName)) {
    this.log.push(
      'Found <span class="event-attribute">event attribute</span> (<strong>' +
      attrName + '</strong>) on <strong><code>&lt;' + tag + '&gt;</code></strong> element.'
    );
  }
  else if (isDeprecatedAttribute(tag, attrName)) {
    this.log.push(
      'Found <span class="deprecated-attribute">deprecated</span> <strong>' +
        attrName + '</strong> attribute on <strong><code>&lt;' + tag + '&gt;</code></strong> element.'
    );
  }
  else if (isStyleAttribute(attrName)) {
    this.log.push(
      'Found <span class="style-attribute">style attribute</span> on <strong><code>&lt;' +
        tag + '&gt;</code></strong> element.'
    );
  }
  else if (isInaccessibleAttribute(attrName, attrValue)) {
    this.log.push(
      'Found <span class="inaccessible-attribute">inaccessible attribute</span> ' +
        '(on <strong><code>&lt;' + tag + '&gt;</code></strong> element).'
    );
  }
};

Lint.prototype.testChars = function(chars) {
  this._lastElement = '';
  if (/(&nbsp;\s*){2,}/.test(chars)) {
    this.log.push('Found repeating <strong><code>&amp;nbsp;</code></strong> sequence. Try replacing it with styling.');
  }
};

Lint.prototype.test = function(tag, attrName, attrValue) {
  this.testElement(tag);
  this.testAttribute(tag, attrName, attrValue);
};

Lint.prototype.testDoctype = function(doctype) {
  this._doctype = doctype;
};

Lint.prototype.populate = function(writeToElement) {
  if (!this._doctype) {
    this.log.push('No DOCTYPE found.');
  }

  if (this._isElementRepeated) {
    this._reportRepeatingElement();
  }

  var output;
  if (writeToElement) {
    output = this.log.map(function(line) {
      return '<li>' + line + '</li>';
    }).join('');
    writeToElement.innerHTML = '<ol>' + output + '</ol>';
  }
  else if (this.log.length) {
    output = this.log.join('\n - ').replace(/<[^>]+>/g, '');
    console.log(' - ' + output.replace(/&lt;/g, '<').replace(/&gt;/g, '>'));
  }
};

exports.HTMLLint = Lint;