feat(vanilla): add testing infrastructure and tests (NK-wjnczv)

1 files changed, 1855 insertions, 0 deletions

diff --git a/vanilla/node_modules/@asamuzakjp/nwsapi/src/nwsapi.js b/vanilla/node_modules/@asamuzakjp/nwsapi/src/nwsapi.js
new file mode 100644
index 0000000..e118fd5
--- /dev/null
+++ b/vanilla/node_modules/@asamuzakjp/nwsapi/src/nwsapi.js
@@ -0,0 +1,1855 @@
+/**
+ * Forked and modified from nwsapi@2.2.2
+ * - Export to cjs only
+ * - Remove ./modules directory
+ * - Remove unused exported properties
+ * - Remove unused pseudo-classes
+ * - Remove Snapshot.root and resolve document.documentElement on runtime
+ * - Use `let` and `const` as much as possible
+ * - Use `===` and `!==`
+ * - Fix `:nth-of-type()`
+ * - Fix function source for :root, :target and :indeterminate pseudo-classes
+ * - Fix <ident-token>
+ * - Support complex selectors within `:is()` and `:not()`
+ * - Add ::slotted() and ::part() to pseudo-elements list
+ * - Add isContentEditable() function
+ * - Add createMatchingParensRegex() function from upstream
+ * - Invalidate cache for :has() pseudo class
+ * - Optimize some regular expressions
+ */
+/*
+ * Copyright (C) 2007-2019 Diego Perini
+ * All rights reserved.
+ *
+ * nwsapi.js - Fast CSS Selectors API Engine
+ *
+ * Author: Diego Perini <diego.perini at gmail com>
+ * Version: 2.2.0
+ * Created: 20070722
+ * Release: 20220901
+ *
+ * License:
+ *  http://javascript.nwbox.com/nwsapi/MIT-LICENSE
+ * Download:
+ *  http://javascript.nwbox.com/nwsapi/nwsapi.js
+ */
+
+(function Export(global, factory) {
+  'use strict';
+  module.exports = factory;
+})(this, function Factory(global, Export) {
+  const version = 'nwsapi-2.2.2';
+
+  let doc = global.document;
+
+  /**
+   * Generate a regex that matches a balanced set of parentheses.
+   * Outermost parentheses are excluded so any amount of children can be handled.
+   * See https://stackoverflow.com/a/35271017 for reference
+   *
+   * @param {number} depth
+   * @return {string}
+   */
+  function createMatchingParensRegex(depth = 1) {
+    const out = '\\([^)(]*?(?:'.repeat(depth) + '\\([^)(]*?\\)' + '[^)(]*?)*?\\)'.repeat(depth);
+    // remove outermost escaped parens
+    return out.slice(2, out.length - 2);
+  }
+
+  const CFG = {
+    // extensions
+    operators: '[~*^$|]=|=',
+    combinators: '[\\s>+~](?=[^>+~])'
+  };
+
+  const NOT = {
+    // not enclosed in double/single/parens/square
+    doubleEnc: '(?=(?:[^"]*"[^"]*")*[^"]*$)',
+    singleEnc: "(?=(?:[^']*'[^']*')*[^']*$)",
+    parensEnc: '(?![^\\x28]*\\x29)',
+    squareEnc: '(?![^\\x5b]*\\x5d)'
+  };
+
+  const REX = {
+    // regular expressions
+    hasEscapes: /\\/,
+    hexNumbers: /^[0-9a-f]/i,
+    escOrQuote: /^\\|[\x22\x27]/,
+    regExpChar: /(?:(?!\\)[\\^$.*+?()[\]{}|/])/g,
+    trimSpaces: /[\r\n\f]|^\s+|\s+$/g,
+    commaGroup: RegExp('(\\s{0,255},\\s{0,255})' + NOT.squareEnc + NOT.parensEnc, 'g'),
+    splitGroup: /((?:\x28[^\x29]{0,255}\x29|\[[^\]]{0,255}\]|\\.|[^,])+)/g,
+    fixEscapes: /\\([0-9a-f]{1,6}\s?|.)|([\x22\x27])/gi,
+    combineWSP: RegExp('\\s{1,255}' + NOT.singleEnc + NOT.doubleEnc, 'g'),
+    tabCharWSP: RegExp('(\\s?\\t{1,255}\\s?)' + NOT.singleEnc + NOT.doubleEnc, 'g'),
+    pseudosWSP: RegExp('\\s{1,255}([-+])\\s{1,255}' + NOT.squareEnc, 'g')
+  };
+
+  const STD = {
+    combinator: /\s?([>+~])\s?/g,
+    apimethods: /^(?:[a-z]+|\*)\|/i,
+    namespaces: /(\*|[a-z]+)\|[-a-z]+/i
+  };
+
+  const GROUPS = {
+    // pseudo-classes requiring parameters
+    logicalsel: '(is|where|matches|not|has)(?:\\x28\\s?(' + createMatchingParensRegex(3) + ')\\s?\\x29)',
+    treestruct: '(nth(?:-last)?(?:-child|-of-type))(?:\\x28\\s?(even|odd|(?:[-+]?\\d*)(?:n\\s?[-+]?\\s?\\d*)?)\\s?(?:\\x29|$))',
+    // pseudo-classes not requiring parameters
+    locationpc: '(any-link|link|visited|target)\\b',
+    structural: '(root|empty|(?:(?:first|last|only)(?:-child|-of-type)))\\b',
+    inputstate: '(enabled|disabled|read-(?:only|write)|placeholder-shown|default)\\b',
+    inputvalue: '(checked|indeterminate)\\b',
+    // pseudo-classes for parsing only selectors
+    pseudoNop: '(autofill|-webkit-autofill)\\b',
+    // pseudo-elements starting with single colon (:)
+    pseudoSng: '(after|before|first-letter|first-line)\\b',
+    // pseudo-elements starting with double colon (::)
+    pseudoDbl: ':(after|before|first-letter|first-line|selection|part|placeholder|slotted|-webkit-[-a-z0-9]{2,})\\b'
+  };
+
+  const Patterns = {
+    // pseudo-classes
+    treestruct: RegExp('^:(?:' + GROUPS.treestruct + ')(.*)', 'i'),
+    structural: RegExp('^:(?:' + GROUPS.structural + ')(.*)', 'i'),
+    inputstate: RegExp('^:(?:' + GROUPS.inputstate + ')(.*)', 'i'),
+    inputvalue: RegExp('^:(?:' + GROUPS.inputvalue + ')(.*)', 'i'),
+    locationpc: RegExp('^:(?:' + GROUPS.locationpc + ')(.*)', 'i'),
+    logicalsel: RegExp('^:(?:' + GROUPS.logicalsel + ')(.*)', 'i'),
+    pseudoNop: RegExp('^:(?:' + GROUPS.pseudoNop + ')(.*)', 'i'),
+    pseudoSng: RegExp('^:(?:' + GROUPS.pseudoSng + ')(.*)', 'i'),
+    pseudoDbl: RegExp('^:(?:' + GROUPS.pseudoDbl + ')(.*)', 'i'),
+    // combinator symbols
+    children: /^\s?>\s?(.*)/,
+    adjacent: /^\s?\+\s?(.*)/,
+    relative: /^\s?~\s?(.*)/,
+    ancestor: /^\s+(.*)/,
+    // universal & namespace
+    universal: /^\*(.*)/,
+    namespace: /^(\w+|\*)?\|(.*)/
+  };
+
+  // emulate firefox error strings
+  const qsNotArgs = 'Not enough arguments';
+  const qsInvalid = ' is not a valid selector';
+
+  // detect structural pseudo-classes in selectors
+  const reNthElem = /(:nth(?:-last)?-child)/i;
+  const reNthType = /(:nth(?:-last)?-of-type)/i;
+
+  // placeholder for global regexp
+  let reOptimizer;
+  let reValidator;
+
+  // special handling configuration flags
+  const Config = {
+    IDS_DUPES: true,
+    MIXEDCASE: true,
+    LOGERRORS: true,
+    VERBOSITY: true
+  };
+
+  let NAMESPACE;
+  let QUIRKS_MODE;
+  let HTML_DOCUMENT;
+
+  const ATTR_STD_OPS = {
+    '=': 1,
+    '^=': 1,
+    '$=': 1,
+    '|=': 1,
+    '*=': 1,
+    '~=': 1
+  };
+
+  const HTML_TABLE = {
+    accept: 1,
+    'accept-charset': 1,
+    align: 1,
+    alink: 1,
+    axis: 1,
+    bgcolor: 1,
+    charset: 1,
+    checked: 1,
+    clear: 1,
+    codetype: 1,
+    color: 1,
+    compact: 1,
+    declare: 1,
+    defer: 1,
+    dir: 1,
+    direction: 1,
+    disabled: 1,
+    enctype: 1,
+    face: 1,
+    frame: 1,
+    hreflang: 1,
+    'http-equiv': 1,
+    lang: 1,
+    language: 1,
+    link: 1,
+    media: 1,
+    method: 1,
+    multiple: 1,
+    nohref: 1,
+    noresize: 1,
+    noshade: 1,
+    nowrap: 1,
+    readonly: 1,
+    rel: 1,
+    rev: 1,
+    rules: 1,
+    scope: 1,
+    scrolling: 1,
+    selected: 1,
+    shape: 1,
+    target: 1,
+    text: 1,
+    type: 1,
+    valign: 1,
+    valuetype: 1,
+    vlink: 1
+  };
+
+  const Combinators = {};
+
+  const Selectors = {};
+
+  const Operators = {
+    '=': {
+      p1: '^',
+      p2: '$',
+      p3: 'true'
+    },
+    '^=': {
+      p1: '^',
+      p2: '',
+      p3: 'true'
+    },
+    '$=': {
+      p1: '',
+      p2: '$',
+      p3: 'true'
+    },
+    '*=': {
+      p1: '',
+      p2: '',
+      p3: 'true'
+    },
+    '|=': {
+      p1: '^',
+      p2: '(-|$)',
+      p3: 'true'
+    },
+    '~=': {
+      p1: '(^|\\s)',
+      p2: '(\\s|$)',
+      p3: 'true'
+    }
+  };
+
+  const concatCall = function (nodes, callback) {
+    let i = 0;
+    const l = nodes.length;
+    const list = Array(l);
+    while (l > i) {
+      if (callback(list[i] = nodes[i]) === false) {
+        break;
+      }
+      ++i;
+    }
+    return list;
+  };
+
+  const concatList = function (list, nodes) {
+    let i = -1;
+    let l = nodes.length;
+    while (l--) {
+      list[list.length] = nodes[++i];
+    }
+    return list;
+  };
+
+  let hasDupes = false;
+
+  const documentOrder = function (a, b) {
+    if (!hasDupes && a === b) {
+      hasDupes = true;
+      return 0;
+    }
+    return a.compareDocumentPosition(b) & 4 ? -1 : 1;
+  };
+
+  const unique = function (nodes) {
+    let i = 0;
+    let j = -1;
+    let l = nodes.length + 1;
+    const list = [];
+    while (--l) {
+      if (nodes[i++] === nodes[i]) {
+        continue;
+      }
+      list[++j] = nodes[i - 1];
+    }
+    hasDupes = false;
+    return list;
+  };
+
+  // check context for mixed content
+  const hasMixedCaseTagNames = function (context) {
+    const api = 'getElementsByTagNameNS';
+
+    // current host context (ownerDocument)
+    context = context.ownerDocument || context;
+
+    // documentElement (root) element namespace or default html/xhtml namespace
+    const ns = context.documentElement && context.documentElement.namespaceURI
+       ? context.documentElement.namespaceURI
+       : 'http://www.w3.org/1999/xhtml';
+
+    // checking the number of non HTML nodes in the document
+    return (context[api]('*', '*').length - context[api](ns, '*').length) > 0;
+  };
+
+  // check if the document type is HTML
+  const isHTML = function (node) {
+    const doc = node.ownerDocument || node;
+    return doc.nodeType === 9 && doc.contentType === 'text/html';
+  };
+
+  // convert single codepoint to UTF-16 encoding
+  const codePointToUTF16 = function (codePoint) {
+    // out of range, use replacement character
+    if (codePoint < 1 || codePoint > 0x10ffff ||
+        (codePoint > 0xd7ff && codePoint < 0xe000)) {
+      return '\\ufffd';
+    }
+    // javascript strings are UTF-16 encoded
+    if (codePoint < 0x10000) {
+      const lowHex = '000' + codePoint.toString(16);
+      return '\\u' + lowHex.substr(lowHex.length - 4);
+    }
+    // supplementary high + low surrogates
+    return '\\u' + (((codePoint - 0x10000) >> 0x0a) + 0xd800).toString(16) +
+           '\\u' + (((codePoint - 0x10000) % 0x400) + 0xdc00).toString(16);
+  };
+
+  // convert single codepoint to string
+  const stringFromCodePoint = function (codePoint) {
+    // out of range, use replacement character
+    if (codePoint < 1 || codePoint > 0x10ffff ||
+        (codePoint > 0xd7ff && codePoint < 0xe000)) {
+      return '\ufffd';
+    }
+    if (codePoint < 0x10000) {
+      return String.fromCharCode(codePoint);
+    }
+    return String.fromCodePoint(codePoint);
+  };
+
+  // convert escape sequence in a CSS string or identifier
+  // to javascript string with javascript escape sequences
+  const convertEscapes = function (str) {
+    return REX.hasEscapes.test(str)
+      ? str.replace(REX.fixEscapes, function (substring, p1, p2) {
+        // unescaped " or '
+        return p2
+          ? '\\' + p2
+          // javascript strings are UTF-16 encoded
+          : REX.hexNumbers.test(p1)
+            ? codePointToUTF16(parseInt(p1, 16))
+            // \' \"
+            : REX.escOrQuote.test(p1)
+              ? substring
+              // \g \h \. \# etc
+              : p1;
+      })
+      : str;
+  };
+
+  // convert escape sequence in a CSS string or identifier
+  // to javascript string with characters representations
+  const unescapeIdentifier = function (str) {
+    return REX.hasEscapes.test(str)
+      ? str.replace(REX.fixEscapes, function (substring, p1, p2) {
+        // unescaped " or '
+        return p2 || (REX.hexNumbers.test(p1)
+          ? stringFromCodePoint(parseInt(p1, 16))
+          // \' \"
+          : REX.escOrQuote.test(p1)
+            ? substring
+            // \g \h \. \# etc
+            : p1);
+      })
+      : str;
+  };
+
+  // empty set
+  const none = [];
+
+  // cached lambdas
+  const matchLambdas = {};
+  const selectLambdas = {};
+
+  // cached resolvers
+  let matchResolvers = {};
+  let selectResolvers = {};
+
+  const method = {
+    '#': 'getElementById',
+    '*': 'getElementsByTagName',
+    '|': 'getElementsByTagNameNS',
+    '.': 'getElementsByClassName'
+  };
+
+  // find duplicate ids using iterative walk
+  const byIdRaw = function (id, context) {
+    let node = context;
+    const nodes = [];
+    let next = node.firstElementChild;
+    while ((node = next)) {
+      node.id === id && nodes.push(node);
+      if ((next = node.firstElementChild || node.nextElementSibling)) {
+        continue;
+      }
+      while (!next && (node = node.parentElement) && node !== context) {
+        next = node.nextElementSibling;
+      }
+    }
+    return nodes;
+  };
+
+  // context agnostic getElementById
+  const byId = function (id, context) {
+    let e;
+    const api = method['#'];
+
+    // duplicates id allowed
+    if (Config.IDS_DUPES === false) {
+      if (api in context) {
+        e = context[api](id);
+        return e ? [e] : none;
+      }
+    } else if ('all' in context) {
+      if ((e = context.all[id])) {
+        if (e.nodeType === 1) {
+          return e.getAttribute('id') !== id ? [] : [e];
+        } else if (id === 'length') {
+          e = context[api](id);
+          return e ? [e] : none;
+        }
+        const nodes = [];
+        for (let i = 0, l = e.length; l > i; ++i) {
+          if (e[i].id === id) {
+            nodes.push(e[i]);
+          }
+        }
+        return nodes.length ? nodes : none;
+      } else {
+        return none;
+      }
+    }
+
+    return byIdRaw(id, context);
+  };
+
+  // context agnostic getElementsByTagName
+  const byTag = function (tag, context) {
+    let e;
+    let nodes;
+    const api = method['*'];
+
+    // DOCUMENT_NODE (9) & ELEMENT_NODE (1)
+    if (api in context) {
+      return Array.prototype.slice.call(context[api](tag));
+    } else {
+      tag = tag.toLowerCase();
+      // DOCUMENT_FRAGMENT_NODE (11)
+      if ((e = context.firstElementChild)) {
+        if (!(e.nextElementSibling || tag === '*' || e.localName === tag)) {
+          return Array.prototype.slice.call(e[api](tag));
+        } else {
+          nodes = [];
+          do {
+            if (tag === '*' || e.localName === tag) {
+              nodes.push(e);
+            }
+            concatList(nodes, e[api](tag));
+          } while ((e = e.nextElementSibling));
+        }
+      } else {
+        nodes = none;
+      }
+    }
+    return nodes;
+  };
+
+  // context agnostic getElementsByClassName
+  const byClass = function (cls, context) {
+    let e;
+    let nodes;
+    const api = method['.'];
+    let reCls;
+    // DOCUMENT_NODE (9) & ELEMENT_NODE (1)
+    if (api in context) {
+      return Array.prototype.slice.call(context[api](cls));
+    } else {
+      // DOCUMENT_FRAGMENT_NODE (11)
+      if ((e = context.firstElementChild)) {
+        reCls = RegExp('(^|\\s)' + cls + '(\\s|$)', QUIRKS_MODE ? 'i' : '');
+        if (!(e.nextElementSibling || reCls.test(e.className))) {
+          return Array.prototype.slice.call(e[api](cls));
+        } else {
+          nodes = [];
+          do {
+            if (reCls.test(e.className)) {
+              nodes.push(e);
+            }
+            concatList(nodes, e[api](cls));
+          } while ((e = e.nextElementSibling));
+        }
+      } else nodes = none;
+    }
+    return nodes;
+  };
+
+  const compat = {
+    '#': function (c, n) {
+      REX.hasEscapes.test(n) && (n = unescapeIdentifier(n));
+      return function (e, f) {
+        return byId(n, c);
+      };
+    },
+    '*': function (c, n) {
+      REX.hasEscapes.test(n) && (n = unescapeIdentifier(n));
+      return function (e, f) {
+        return byTag(n, c);
+      };
+    },
+    '|': function (c, n) {
+      REX.hasEscapes.test(n) && (n = unescapeIdentifier(n));
+      return function (e, f) {
+        return byTag(n, c);
+      };
+    },
+    '.': function (c, n) {
+      REX.hasEscapes.test(n) && (n = unescapeIdentifier(n));
+      return function (e, f) {
+        return byClass(n, c);
+      };
+    }
+  };
+
+  // namespace aware hasAttribute
+  // helper for XML/XHTML documents
+  const hasAttributeNS = function (e, name) {
+    let i;
+    let l;
+    const attr = e.getAttributeNames();
+    name = RegExp(':?' + name + '$', HTML_DOCUMENT ? 'i' : '');
+    for (i = 0, l = attr.length; l > i; ++i) {
+      if (name.test(attr[i])) {
+        return true;
+      }
+    }
+    return false;
+  };
+
+  // fast resolver for the :nth-child() and :nth-last-child() pseudo-classes
+  const nthElement = (function () {
+    let idx = 0;
+    let len = 0;
+    let set = 0;
+    let parent;
+    let parents = [];
+    let nodes = [];
+    return function (element, dir) {
+      // ensure caches are emptied after each run, invoking with dir = 2
+      if (dir === 2) {
+        idx = 0; len = 0; set = 0; nodes = []; parents = []; parent = undefined;
+        return -1;
+      }
+      let e, i, j, k, l;
+      if (parent === element.parentElement) {
+        i = set; j = idx; l = len;
+      } else {
+        l = parents.length;
+        parent = element.parentElement;
+        for (i = -1, j = 0, k = l - 1; l > j; ++j, --k) {
+          if (parents[j] === parent) {
+            i = j;
+            break;
+          }
+          if (parents[k] === parent) {
+            i = k;
+            break;
+          }
+        }
+        if (i < 0) {
+          parents[i = l] = parent;
+          l = 0; nodes[i] = [];
+          e = (parent && parent.firstElementChild) || element;
+          while (e) {
+            nodes[i][l] = e;
+            if (e === element) {
+              j = l;
+            }
+            e = e.nextElementSibling;
+            ++l;
+          }
+          set = i; idx = 0; len = l;
+          if (l < 2) {
+            return l;
+          }
+        } else {
+          l = nodes[i].length;
+          set = i;
+        }
+      }
+      if (element !== nodes[i][j] && element !== nodes[i][j = 0]) {
+        for (j = 0, e = nodes[i], k = l - 1; l > j; ++j, --k) {
+          if (e[j] === element) {
+            break;
+          }
+          if (e[k] === element) {
+            j = k;
+            break;
+          }
+        }
+      }
+      idx = j + 1; len = l;
+      return dir ? l - j : idx;
+    };
+  })();
+
+  // fast resolver for the :nth-of-type() and :nth-last-of-type() pseudo-classes
+  const nthOfType = (function () {
+    let idx = 0;
+    let len = 0;
+    let set = 0;
+    let parent;
+    let parents = [];
+    let nodes = [];
+    return function (element, dir) {
+      // ensure caches are emptied after each run, invoking with dir = 2
+      if (dir === 2) {
+        idx = 0; len = 0; set = 0; nodes = []; parents = []; parent = undefined;
+        return -1;
+      }
+      const name = element.localName;
+      const nsURI = element.namespaceURI;
+      if (nsURI !== 'http://www.w3.org/1999/xhtml') {
+        idx = 0; len = 0; set = 0; nodes = []; parents = []; parent = undefined;
+      }
+      let e;
+      let i;
+      let j;
+      let k;
+      let l;
+      if (nodes[set] && nodes[set][name] && parent === element.parentElement) {
+        i = set;
+        j = idx;
+        l = len;
+      } else {
+        l = parents.length;
+        parent = element.parentElement;
+        for (i = -1, j = 0, k = l - 1; l > j; ++j, --k) {
+          if (parents[j] === parent) {
+            i = j;
+            break;
+          }
+          if (parents[k] === parent) {
+            i = k;
+            break;
+          }
+        }
+        if (i < 0 || !nodes[i][name]) {
+          parents[i = l] = parent;
+          nodes[i] || (nodes[i] = Object());
+          l = 0; nodes[i][name] = [];
+          e = (parent && parent.firstElementChild) || element;
+          while (e) {
+            if (e === element) {
+              j = l;
+            }
+            if (e.localName === name && e.namespaceURI === nsURI) {
+              nodes[i][name][l] = e;
+              ++l;
+            }
+            e = e.nextElementSibling;
+          }
+          set = i; idx = j; len = l;
+          if (l < 2) {
+            return l;
+          }
+        } else {
+          l = nodes[i][name].length;
+          set = i;
+        }
+      }
+      if (element !== nodes[i][name][j] && element !== nodes[i][name][j = 0]) {
+        for (j = 0, e = nodes[i][name], k = l - 1; l > j; ++j, --k) {
+          if (e[j] === element) {
+            break;
+          }
+          if (e[k] === element) {
+            j = k;
+            break;
+          }
+        }
+      }
+      idx = j + 1; len = l;
+      return dir ? l - j : idx;
+    };
+  })();
+
+  // check if the node is the target
+  const isTarget = function (node) {
+    const doc = node.ownerDocument || node;
+    const { hash } = new URL(doc.URL);
+    if (node.id && hash === `#${node.id}` && doc.contains(node)) {
+      return true;
+    }
+    return false;
+  };
+
+  // check if node is indeterminate
+  const isIndeterminate = function (node) {
+    if ((node.indeterminate && node.localName === 'input' &&
+         node.type === 'checkbox') ||
+        (node.localName === 'progress' && !node.hasAttribute('value'))) {
+      return true;
+    }
+    if (node.localName === 'input' && node.type === 'radio' &&
+        !node.hasAttribute('checked')) {
+      const nodeName = node.name;
+      let parent = node.parentNode;
+      while (parent) {
+        if (parent.localName === 'form') {
+          break;
+        }
+        parent = parent.parentNode;
+      }
+      if (!parent) {
+        const doc = node.ownerDocument;
+        parent = doc.documentElement;
+      }
+      const items = parent.getElementsByTagName('input');
+      const l = items.length;
+      let checked;
+      for (let i = 0; i < l; i++) {
+        const item = items[i];
+        if (item.getAttribute('type') === 'radio') {
+          if (nodeName) {
+            if (item.getAttribute('name') === nodeName) {
+              checked = !!item.checked;
+            }
+          } else if (!item.hasAttribute('name')) {
+            checked = !!item.checked;
+          }
+          if (checked) {
+            break;
+          }
+        }
+      }
+      if (!checked) {
+        return true;
+      }
+    }
+    return false;
+  };
+
+  // check if node content is editable
+  const isContentEditable = function (node) {
+    let attrValue = 'inherit';
+    if (node.hasAttribute('contenteditable')) {
+      attrValue = node.getAttribute('contenteditable');
+    }
+    switch (attrValue) {
+      case '':
+      case 'plaintext-only':
+      case 'true':
+        return true;
+      case 'false':
+        return false;
+      default:
+        if (node.parentNode && node.parentNode.nodeType === 1) {
+          return isContentEditable(node.parentNode);
+        }
+        return false;
+    }
+  };
+
+  // build validation regexps used by the engine
+  const setIdentifierSyntax = function () {
+    //
+    // NOTE: SPECIAL CASES IN CSS SYNTAX PARSING RULES
+    //
+    // The <EOF-token> https://drafts.csswg.org/css-syntax/#typedef-eof-token
+    // allow mangled|unclosed selector syntax at the end of selectors strings
+    //
+    // Literal equivalent hex representations of the characters: " ' ` ] )
+    //
+    //     \\x22 = " - double quotes    \\x5b = [ - open square bracket
+    //     \\x27 = ' - single quote     \\x5d = ] - closed square bracket
+    //     \\x60 = ` - back tick        \\x28 = ( - open round parens
+    //     \\x5c = \ - back slash       \\x29 = ) - closed round parens
+    //
+    // using hex format prevents false matches of opened/closed instances
+    // pairs, coloring breakage and other editors highlightning problems.
+    //
+
+    // @see https://drafts.csswg.org/css-syntax-3/#ident-token-diagram
+    const nonascii = '[^\\x00-\\x9f]';
+    const esctoken = '\\\\(?:[^\\r\\n\\f\\da-f]|[\\da-f]{1,6}\\s{0,255})';
+    const identifier =
+      '(?:--|-?(?:[a-z_]|' + nonascii + '|' + esctoken + '))' +
+      '(?:[\\w-]|' + nonascii + '|' + esctoken + ')*';
+
+    const pseudonames = '[-\\w]+';
+    const pseudoparms = '(?:[-+]?\\d*)(?:n\\s?[-+]?\\s?\\d*)';
+    const doublequote = '"[^"\\\\]*(?:\\\\.[^"\\\\]*)*(?:"|$)';
+    const singlequote = "'[^'\\\\]*(?:\\\\.[^'\\\\]*)*(?:'|$)";
+
+    const attrparser = identifier + '|' + doublequote + '|' + singlequote;
+
+    const attrvalues = '([\\x22\\x27]?)((?!\\3)*|(?:\\\\?.)*?)(?:\\3|$)';
+
+    const attributes =
+      '\\[' +
+        // attribute presence
+        '(?:\\*\\|)?\\s?(' + identifier + '(?::' + identifier + ')?)\\s?' +
+        '(?:(' + CFG.operators + ')\\s?(?:' + attrparser + '))?' +
+        // attribute case sensitivity
+        '(?:\\s?\\b(i))?\\s?' +
+      '(?:\\]|$)';
+
+    const attrmatcher = attributes.replace(attrparser, attrvalues);
+
+    const pseudoclass =
+      '(?:\\x28\\s*' +
+        '(?:' + pseudoparms + '?)?|' +
+        // universal * &
+        // namespace *|*
+        '[*|]|' +
+        '(?:' +
+          '(?::' + pseudonames + '(?:\\x28' + pseudoparms + '?(?:\\x29|$))?)|' +
+          '(?:[.#]?' + identifier + ')|' +
+          '(?:' + attributes + ')' +
+        ')+|' +
+        '\\s?[>+~]\\s?|' +
+        '\\s?,\\s?|' +
+        '\\s|' +
+        '\\x29|$' +
+      ')*';
+
+    const standardValidator =
+      '(?=\\s?[^>+~(){}<])' +
+      '(?:' +
+        // universal * &
+        // namespace *|*
+        '\\*|\\||' +
+        '(?:[.#]?' + identifier + ')+|' +
+        '(?:' + attributes + ')+|' +
+        '(?:::?' + pseudonames + pseudoclass + ')|' +
+        '(?:\\s?' + CFG.combinators + '\\s?)|' +
+        '\\s?,\\s?|' +
+        '\\s?' +
+      ')+';
+
+    // the following global RE is used to return the
+    // deepest localName in selector strings and then
+    // use it to retrieve all possible matching nodes
+    // that will be filtered by compiled resolvers
+    reOptimizer = RegExp(
+      '(?:([.:#*]?)(' + identifier + ')' +
+        '(?::[-\\w]+|\\[[^\\]]+(?:\\]|$)|\\x28[^\\x29]+(?:\\x29|$))*' +
+      ')$', 'i');
+
+    // global
+    reValidator = RegExp(standardValidator, 'gi');
+
+    Patterns.id = RegExp('^#(' + identifier + ')(.*)', 'i');
+    Patterns.tagName = RegExp('^(' + identifier + ')(.*)', 'i');
+    Patterns.className = RegExp('^\\.(' + identifier + ')(.*)', 'i');
+    Patterns.attribute = RegExp('^(?:' + attrmatcher + ')(.*)');
+  };
+
+  // configure the engine to use special handling
+  const configure = function (option, clear) {
+    if (typeof option === 'string') {
+      return !!Config[option];
+    }
+    if (typeof option !== 'object') {
+      return Config;
+    }
+    for (const i in option) {
+      Config[i] = !!option[i];
+    }
+    // clear lambda cache
+    if (clear) {
+      matchResolvers = {};
+      selectResolvers = {};
+    }
+    setIdentifierSyntax();
+    return true;
+  };
+
+  // centralized error and exceptions handling
+  const emit = function (message, proto) {
+    let err;
+    if (Config.VERBOSITY) {
+      if (global[proto]) {
+        err = new global[proto](message);
+      } else {
+        err = new global.DOMException(message, 'SyntaxError');
+      }
+      throw err;
+    }
+    if (Config.LOGERRORS && console && console.log) {
+      console.log(message);
+    }
+  };
+
+  // passed to resolvers
+  const Snapshot = {
+    doc: null,
+    from: null,
+    byTag: null,
+    first: null,
+    match: null,
+    ancestor: null,
+    nthOfType: null,
+    nthElement: null,
+    hasAttributeNS: null,
+    isTarget: null,
+    isIndeterminate: null,
+    isContentEditable: null
+  };
+
+  // context
+  let lastContext;
+
+  const switchContext = function (context, force) {
+    const oldDoc = doc;
+    doc = context.ownerDocument || context;
+    if (force || oldDoc !== doc) {
+      // force a new check for each document change
+      // performed before the next select operation
+      HTML_DOCUMENT = isHTML(doc);
+      QUIRKS_MODE = HTML_DOCUMENT && doc.compatMode.indexOf('CSS') < 0;
+      NAMESPACE = doc.documentElement && doc.documentElement.namespaceURI;
+      Snapshot.doc = doc;
+    }
+    Snapshot.from = context;
+    return context;
+  };
+
+  // selector
+  let lastMatched;
+  let lastSelected;
+
+  const F_INIT = '"use strict";return function Resolver(c,f,x,r)';
+
+  const S_HEAD = 'var e,n,o,j=r.length-1,k=-1';
+  const M_HEAD = 'var e,n,o';
+
+  const S_LOOP = 'main:while((e=c[++k]))';
+  const N_LOOP = 'main:while((e=c.item(++k)))';
+  const M_LOOP = 'e=c;';
+
+  const S_BODY = 'r[++j]=c[k];';
+  const N_BODY = 'r[++j]=c.item(k);';
+  const M_BODY = '';
+
+  const S_TAIL = 'continue main;';
+  const M_TAIL = 'r=true;';
+
+  const S_TEST = 'if(f(c[k])){break main;}';
+  const N_TEST = 'if(f(c.item(k))){break main;}';
+  const M_TEST = 'f(c);';
+
+  let S_VARS = [];
+  let M_VARS = [];
+
+  // build conditional code to check components of selector strings
+  const compileSelector = function (expression, source, mode, callback) {
+    // N is the negation pseudo-class flag
+    // D is the default inverted negation flag
+    let a;
+    let b;
+    let n;
+    let f;
+    let name;
+    let NS;
+    const N = '';
+    const D = '!';
+    let compat;
+    let expr;
+    let match;
+    let result;
+    let status;
+    let symbol;
+    let test;
+    let type;
+    let selector = expression;
+    let vars;
+
+    // original 'select' or 'match' selector string before normalization
+    const selectorString = mode ? lastSelected : lastMatched;
+
+    // isolate selector combinators/components and normalize whitespace
+    selector = selector.replace(STD.combinator, '$1'); // .replace(STD.whitespace, ' ');
+
+    let selectorRecursion = true;
+    while (selector) {
+      // get namespace prefix if present or get first char of selector
+      symbol = STD.apimethods.test(selector) ? '|' : selector[0];
+
+      switch (symbol) {
+        // universal resolver
+        case '*':
+          match = selector.match(Patterns.universal);
+          if (N === '!') {
+            source = 'if(' + N + 'true' + '){' + source + '}';
+          }
+          break;
+        // id resolver
+        case '#':
+          match = selector.match(Patterns.id);
+          source = 'if(' + N + '(/^' + match[1] + '$/.test(e.getAttribute("id"))' +
+            ')){' + source + '}';
+          break;
+        // class name resolver
+        case '.':
+          match = selector.match(Patterns.className);
+          compat = (QUIRKS_MODE ? 'i' : '') + '.test(e.getAttribute("class"))';
+          source = 'if(' + N + '(/(^|\\s)' + match[1] + '(\\s|$)/' + compat +
+            ')){' + source + '}';
+          break;
+        // tag name resolver
+        case (/[_a-z]/i.test(symbol) ? symbol : undefined):
+          match = selector.match(Patterns.tagName);
+          source = 'if(' + N + '(e.localName' +
+            (Config.MIXEDCASE || hasMixedCaseTagNames(doc)
+              ? '=="' + match[1].toLowerCase() + '"'
+              : '=="' + match[1].toUpperCase() + '"') +
+            ')){' + source + '}';
+          break;
+        // namespace resolver
+        case '|':
+          match = selector.match(Patterns.namespace);
+          if (match[1] === '*') {
+            source = 'if(' + N + 'true){' + source + '}';
+          } else if (!match[1]) {
+            source = 'if(' + N + '(!e.namespaceURI)){' + source + '}';
+          } else if (typeof match[1] === 'string' && doc.documentElement &&
+                     doc.documentElement.prefix === match[1]) {
+            source = 'if(' + N + '(e.namespaceURI=="' + NAMESPACE + '")){' + source + '}';
+          } else {
+            emit('\'' + selectorString + '\'' + qsInvalid);
+          }
+          break;
+        // attributes resolver
+        case '[':
+          match = selector.match(Patterns.attribute);
+          NS = match[0].match(STD.namespaces);
+          name = match[1];
+          expr = name.split(':');
+          expr = expr.length === 2 ? expr[1] : expr[0];
+          if (match[2] && !(test = Operators[match[2]])) {
+            emit('\'' + selectorString + '\'' + qsInvalid);
+            return '';
+          }
+          if (match[4] === '') {
+            test = match[2] === '~='
+              ? { p1: '^\\s', p2: '+$', p3: 'true' }
+              : match[2] in ATTR_STD_OPS && match[2] !== '~='
+                ? { p1: '^', p2: '$', p3: 'true' }
+                : test;
+          } else if (match[2] === '~=' && match[4].includes(' ')) {
+            // whitespace separated list but value contains space
+            source = 'if(' + N + 'false){' + source + '}';
+            break;
+          } else if (match[4]) {
+            match[4] = convertEscapes(match[4]).replace(REX.regExpChar, '\\$&');
+          }
+          type = match[5] === 'i' || (HTML_DOCUMENT && HTML_TABLE[expr.toLowerCase()])
+            ? 'i'
+            : '';
+          source =
+            'if(' + N + '(' +
+              (!match[2]
+                ? (NS ? 's.hasAttributeNS(e,"' + name + '")' : 'e.hasAttribute&&e.hasAttribute("' + name + '")')
+                : !match[4] && ATTR_STD_OPS[match[2]] && match[2] !== '~='
+                  ? 'e.getAttribute&&e.getAttribute("' + name + '")==""'
+                  : '(/' + test.p1 + match[4] + test.p2 + '/' + type + ').test(e.getAttribute&&e.getAttribute("' + name + '"))==' + test.p3) +
+            ')){' + source + '}';
+          break;
+        // *** General sibling combinator
+        // E ~ F (F relative sibling of E)
+        case '~':
+          match = selector.match(Patterns.relative);
+          source = 'n=e;while((e=e.previousElementSibling)){' + source + '}e=n;';
+          break;
+        // *** Adjacent sibling combinator
+        // E + F (F adiacent sibling of E)
+        case '+':
+          match = selector.match(Patterns.adjacent);
+          source = 'n=e;if((e=e.previousElementSibling)){' + source + '}e=n;';
+          break;
+        // *** Descendant combinator
+        // E F (E ancestor of F)
+        case '\x09':
+        case '\x20':
+          match = selector.match(Patterns.ancestor);
+          source = 'n=e;while((e=e.parentElement)){' + source + '}e=n;';
+          break;
+        // *** Child combinator
+        // E > F (F children of E)
+        case '>':
+          match = selector.match(Patterns.children);
+          source = 'n=e;if((e=e.parentElement)){' + source + '}e=n;';
+          break;
+        // *** user supplied combinators extensions
+        case (symbol in Combinators ? symbol : undefined):
+          // for other registered combinators extensions
+          match[match.length - 1] = '*';
+          source = Combinators[symbol](match) + source;
+          break;
+        // *** tree-structural pseudo-classes
+        // :root, :empty, :first-child, :last-child, :only-child, :first-of-type, :last-of-type, :only-of-type
+        case ':':
+          if ((match = selector.match(Patterns.structural))) {
+            match[1] = match[1].toLowerCase();
+            switch (match[1]) {
+              case 'root':
+                // there can only be one :root element, so exit the loop once found
+                source = 'if(' + N + '(e===s.doc.documentElement)){' + source + (mode ? 'break main;' : '') + '}';
+                break;
+              case 'empty':
+                // matches elements that don't contain elements or text nodes
+                source = 'n=e.firstChild;while(n&&!(/1|3/).test(n.nodeType)){n=n.nextSibling}if(' + D + 'n){' + source + '}';
+                break;
+              // *** child-indexed pseudo-classes
+              // :first-child, :last-child, :only-child
+              case 'only-child':
+                source = 'if(' + N + '(!e.nextElementSibling&&!e.previousElementSibling)){' + source + '}';
+                break;
+              case 'last-child':
+                source = 'if(' + N + '(!e.nextElementSibling)){' + source + '}';
+                break;
+              case 'first-child':
+                source = 'if(' + N + '(!e.previousElementSibling)){' + source + '}';
+                break;
+              // *** typed child-indexed pseudo-classes
+              // :only-of-type, :last-of-type, :first-of-type
+              case 'only-of-type':
+                source = 'o=e.localName;' +
+                  'n=e;while((n=n.nextElementSibling)&&n.localName!=o);if(!n){' +
+                  'n=e;while((n=n.previousElementSibling)&&n.localName!=o);}if(' + D + 'n){' + source + '}';
+                break;
+              case 'last-of-type':
+                source = 'n=e;o=e.localName;while((n=n.nextElementSibling)&&n.localName!=o);if(' + D + 'n){' + source + '}';
+                break;
+              case 'first-of-type':
+                source = 'n=e;o=e.localName;while((n=n.previousElementSibling)&&n.localName!=o);if(' + D + 'n){' + source + '}';
+                break;
+              default:
+                emit('\'' + selectorString + '\'' + qsInvalid);
+            }
+          // *** child-indexed & typed child-indexed pseudo-classes
+          // :nth-child, :nth-of-type, :nth-last-child, :nth-last-of-type
+          } else if ((match = selector.match(Patterns.treestruct))) {
+            match[1] = match[1].toLowerCase();
+            switch (match[1]) {
+              case 'nth-child':
+              case 'nth-of-type':
+              case 'nth-last-child':
+              case 'nth-last-of-type':
+                expr = /-of-type/i.test(match[1]);
+                if (match[1] && match[2]) {
+                  type = /last/i.test(match[1]);
+                  if (match[2] === 'n') {
+                    source = 'if(' + N + 'true){' + source + '}';
+                    break;
+                  } else if (match[2] === '1') {
+                    test = type ? 'next' : 'previous';
+                    source = expr
+                      ? 'n=e;o=e.localName;' +
+                          'while((n=n.' + test + 'ElementSibling)&&n.localName!=o);if(' + D + 'n){' + source + '}'
+                      : 'if(' + N + '!e.' + test + 'ElementSibling){' + source + '}';
+                    break;
+                  } else if (match[2] === 'even' || match[2] === '2n0' || match[2] === '2n+0' || match[2] === '2n') {
+                    test = 'n%2==0';
+                  } else if (match[2] === 'odd' || match[2] === '2n1' || match[2] === '2n+1') {
+                    test = 'n%2==1';
+                  } else {
+                    f = /n/i.test(match[2]);
+                    n = match[2].split('n');
+                    a = parseInt(n[0], 10) || 0;
+                    b = parseInt(n[1], 10) || 0;
+                    if (n[0] === '-') {
+                      a = -1;
+                    }
+                    if (n[0] === '+') {
+                      a = +1;
+                    }
+                    test = (b ? '(n' + (b > 0 ? '-' : '+') + Math.abs(b) + ')' : 'n') + '%' + a + '==0';
+                    test = a >= +1
+                      ? (f
+                          ? 'n>' + (b - 1) + (Math.abs(a) !== 1
+                            ? '&&' + test
+                            : '')
+                          : 'n==' + a)
+                      : a <= -1
+                        ? (f
+                            ? 'n<' + (b + 1) + (Math.abs(a) !== 1
+                              ? '&&' + test
+                              : '')
+                            : 'n==' + a)
+                        : a === 0
+                          ? (n[0]
+                              ? 'n==' + b
+                              : 'n>' + (b - 1))
+                          : 'false';
+                  }
+                  expr = expr ? 'OfType' : 'Element';
+                  type = type ? 'true' : 'false';
+                  source = 'n=s.nth' + expr + '(e,' + type + ');if(' + N + '(' + test + ')){' + source + '}';
+                } else {
+                  emit('\'' + selectorString + '\'' + qsInvalid);
+                }
+                break;
+              default:
+                emit('\'' + selectorString + '\'' + qsInvalid);
+            }
+          // *** logical combination pseudo-classes
+          // :is( s1, [ s2, ... ]), :not( s1, [ s2, ... ])
+          } else if ((match = selector.match(Patterns.logicalsel))) {
+            match[1] = match[1].toLowerCase();
+            expr = match[2].replace(REX.CommaGroup, ',').replace(REX.TrimSpaces, '');
+            switch (match[1]) {
+              // FIXME:
+              case 'is':
+              case 'where':
+              case 'matches':
+                source = 'if(s.match("' + expr.replace(/\x22/g, '\\"') + '",e)){' + source + '}';
+                break;
+              // FIXME:
+              case 'not':
+                source = 'if(!s.match("' + expr.replace(/\x22/g, '\\"') + '",e)){' + source + '}';
+                break;
+              // FIXME:
+              case 'has':
+                // clear cache
+                matchResolvers = {};
+                source = 'if(e.querySelector(":scope ' + expr.replace(/\x22/g, '\\"') + '")){' + source + '}';
+                break;
+              default:
+                emit('\'' + selectorString + '\'' + qsInvalid);
+            }
+          // *** location pseudo-classes
+          // :any-link, :link, :visited, :target
+          } else if ((match = selector.match(Patterns.locationpc))) {
+            match[1] = match[1].toLowerCase();
+            switch (match[1]) {
+              case 'any-link':
+                source = 'if(' + N + '(/^a|area$/i.test(e.localName)&&e.hasAttribute("href")||e.visited)){' + source + '}';
+                break;
+              case 'link':
+                source = 'if(' + N + '(/^a|area$/i.test(e.localName)&&e.hasAttribute("href"))){' + source + '}';
+                break;
+              // FIXME:
+              case 'visited':
+                source = 'if(' + N + '(/^a|area$/i.test(e.localName)&&e.hasAttribute("href")&&e.visited)){' + source + '}';
+                break;
+              case 'target':
+                source = 'if(s.isTarget(e)){' + source + '}';
+                break;
+              default:
+                emit('\'' + selectorString + '\'' + qsInvalid);
+            }
+          // *** user interface and form pseudo-classes
+          // :enabled, :disabled, :read-only, :read-write, :placeholder-shown, :default
+          } else if ((match = selector.match(Patterns.inputstate))) {
+            match[1] = match[1].toLowerCase();
+            switch (match[1]) {
+              // FIXME: lacks custom element support
+              case 'enabled':
+                source = 'if((("form" in e||/^optgroup$/i.test(e.localName))&&"disabled" in e &&e.disabled===false' +
+                  ')){' + source + '}';
+                break;
+              // FIXME: lacks custom element support
+              case 'disabled':
+                // https://html.spec.whatwg.org/#enabling-and-disabling-form-controls:-the-disabled-attribute
+                source = 'if((("form" in e||/^optgroup$/i.test(e.localName))&&"disabled" in e)){' +
+                  // F is true if any of the fieldset elements in the ancestry chain has the disabled attribute specified
+                  // L is true if the first legend element of the fieldset contains the element
+                  'var x=0,N=[],F=false,L=false;' +
+                  'if(!(/^(optgroup|option)$/i.test(e.localName))){' +
+                    'n=e.parentElement;' +
+                    'while(n){' +
+                      'if(n.localName==="fieldset"){' +
+                        'N[x++]=n;' +
+                        'if(n.disabled===true){' +
+                          'F=true;' +
+                          'break;' +
+                        '}' +
+                      '}' +
+                      'n=n.parentElement;' +
+                    '}' +
+                    'for(var x=0;x<N.length;x++){' +
+                      'if((n=s.first("legend",N[x]))&&n.contains(e)){' +
+                        'L=true;' +
+                        'break;' +
+                      '}' +
+                    '}' +
+                  '}' +
+                  'if(e.disabled===true||(F&&!L)){' + source + '}}';
+                break;
+              case 'read-only':
+                source =
+                  'if(' +
+                    '(/^textarea$/i.test(e.localName)&&(e.readOnly||e.disabled))||' +
+                    '(/^input$/i.test(e.localName)&&("|date|datetime-local|email|month|number|password|search|tel|text|time|url|week|".includes("|"+e.type+"|")?(e.readOnly||e.disabled):true))||' +
+                    '(!/^(?:input|textarea)$/i.test(e.localName) && !s.isContentEditable(e))' +
+                  '){' + source + '}';
+                break;
+              case 'read-write':
+                source =
+                  'if(' +
+                    '(/^textarea$/i.test(e.localName)&&!e.readOnly&&!e.disabled)||' +
+                    '(/^input$/i.test(e.localName)&&"|date|datetime-local|email|month|number|password|search|tel|text|time|url|week|".includes("|"+e.type+"|")&&!e.readOnly&&!e.disabled)||' +
+                    '(!/^(?:input|textarea)$/i.test(e.localName) && s.isContentEditable(e))' +
+                  '){' + source + '}';
+                break;
+              // FIXME:
+              case 'placeholder-shown':
+                source =
+                  'if((' +
+                    '(/^input|textarea$/i.test(e.localName))&&e.hasAttribute("placeholder")&&' +
+                    '("|textarea|password|number|search|email|text|tel|url|".includes("|"+e.type+"|"))&&' +
+                    '(!s.match(":focus",e))' +
+                  ')){' + source + '}';
+                break;
+              // FIXME:
+              case 'default':
+                source =
+                  'if(("form" in e && e.form)){' +
+                    'var x=0;n=[];' +
+                    'if(e.type=="image")n=e.form.getElementsByTagName("input");' +
+                    'if(e.type=="submit")n=e.form.elements;' +
+                    'while(n[x]&&e!==n[x]){' +
+                      'if(n[x].type=="image")break;' +
+                      'if(n[x].type=="submit")break;' +
+                      'x++;' +
+                    '}' +
+                  '}' +
+                  'if((e.form&&(e===n[x]&&"|image|submit|".includes("|"+e.type+"|"))||' +
+                    '((/^option$/i.test(e.localName))&&e.defaultSelected)||' +
+                    '(("|radio|checkbox|".includes("|"+e.type+"|"))&&e.defaultChecked)' +
+                  ')){' + source + '}';
+                break;
+              default:
+                emit('\'' + selector_string + '\'' + qsInvalid);
+                break;
+            }
+          // *** input pseudo-classes (for form validation)
+          // :checked, :indeterminate, :valid, :invalid, :in-range, :out-of-range, :required, :optional
+          } else if ((match = selector.match(Patterns.inputvalue))) {
+            match[1] = match[1].toLowerCase();
+            switch (match[1]) {
+              case 'checked':
+                source = 'if(' + N + '(/^input$/i.test(e.localName)&&' +
+                  '("|radio|checkbox|".includes("|"+e.type+"|")&&e.checked)||' +
+                  '(/^option$/i.test(e.localName)&&(e.selected||e.checked))' +
+                  ')){' + source + '}';
+                break;
+              case 'indeterminate':
+                source = 'if(s.isIndeterminate(e)){' + source + '}';
+                break;
+              // FIXME:
+              case 'required':
+                source =
+                  'if(' + N +
+                    '(/^input|select|textarea$/i.test(e.localName)&&e.required)' +
+                  '){' + source + '}';
+                break;
+              // FIXME:
+              case 'optional':
+                source =
+                  'if(' + N +
+                    '(/^input|select|textarea$/i.test(e.localName)&&!e.required)' +
+                  '){' + source + '}';
+                break;
+              // FIXME:
+              case 'invalid':
+                source =
+                  'if(' + N + '((' +
+                    '(/^form$/i.test(e.localName)&&!e.noValidate)||' +
+                    '(e.willValidate&&!e.formNoValidate))&&!e.checkValidity())||' +
+                    '(/^fieldset$/i.test(e.localName)&&s.first(":invalid",e))' +
+                  '){' + source + '}';
+                break;
+              // FIXME:
+              case 'valid':
+                source =
+                  'if(' + N + '((' +
+                    '(/^form$/i.test(e.localName)&&!e.noValidate)||' +
+                    '(e.willValidate&&!e.formNoValidate))&&e.checkValidity())||' +
+                    '(/^fieldset$/i.test(e.localName)&&s.first(":valid",e))' +
+                  '){' + source + '}';
+                break;
+              // FIXME:
+              case 'in-range':
+                source =
+                  'if(' + N +
+                    '(/^input$/i.test(e.localName))&&' +
+                    '(e.willValidate&&!e.formNoValidate)&&' +
+                    '(!e.validity.rangeUnderflow&&!e.validity.rangeOverflow)&&' +
+                    '("|date|datetime-local|month|number|range|time|week|".includes("|"+e.type+"|"))&&' +
+                    '("range"==e.type||e.getAttribute("min")||e.getAttribute("max"))' +
+                  '){' + source + '}';
+                break;
+              // FIXME:
+              case 'out-of-range':
+                source =
+                  'if(' + N +
+                    '(/^input$/i.test(e.localName))&&' +
+                    '(e.willValidate&&!e.formNoValidate)&&' +
+                    '(e.validity.rangeUnderflow||e.validity.rangeOverflow)&&' +
+                    '("|date|datetime-local|month|number|range|time|week|".includes("|"+e.type+"|"))&&' +
+                    '("range"==e.type||e.getAttribute("min")||e.getAttribute("max"))' +
+                  '){' + source + '}';
+                break;
+              default:
+                emit('\'' + selectorString + '\'' + qsInvalid);
+            }
+          // allow pseudo-elements starting with single colon (:)
+          // :after, :before, :first-letter, :first-line
+          // assert: e.type is in double-colon format, like ::after
+          } else if ((match = selector.match(Patterns.pseudoSng))) {
+            source = 'if(e.element&&e.type.toLowerCase()=="' +
+              ':' + match[0].toLowerCase() + '"){e=e.element;' + source + '}';
+          // allow pseudo-elements starting with double colon (::)
+          // ::after, ::before, ::marker, ::placeholder, ::inactive-selection, ::selection, ::-webkit-<foo-bar>
+          // assert: e.type is in double-colon format, like ::after
+          } else if ((match = selector.match(Patterns.pseudoDbl))) {
+            source = 'if(e.element&&e.type.toLowerCase()=="' +
+              match[0].toLowerCase() + '"){e=e.element;' + source + '}';
+          // placeholder for parsed only no-op selectors
+          } else if ((match = selector.match(Patterns.pseudoNop))) {
+            source = 'if(' + N + 'false' + '){' + source + '}';
+          } else {
+            // reset
+            expr = false;
+            status = false;
+            // process registered selector extensions
+            for (expr in Selectors) {
+              if ((match = selector.match(Selectors[expr].Expression))) {
+                result = Selectors[expr].Callback(match, source, mode, callback);
+                if ('match' in result) {
+                  match = result.match;
+                }
+                vars = result.modvar;
+                if (mode) {
+                  // add extra select() vars
+                  vars && !S_VARS.includes(vars) && S_VARS.push(vars);
+                } else {
+                  // add extra match() vars
+                  vars && M_VARS.includes(vars) && M_VARS.push(vars);
+                }
+                // extension source code
+                source = result.source;
+                // extension status code
+                status = result.status;
+                // break on status error
+                if (status) { break; }
+              }
+            }
+            if (!status) {
+              emit('unknown pseudo-class selector \'' + selector + '\'');
+              return '';
+            }
+            if (!expr) {
+              emit('unknown token in selector \'' + selector + '\'');
+              return '';
+            }
+          }
+          break;
+        default:
+          selectorRecursion = false;
+          emit('\'' + selectorString + '\'' + qsInvalid);
+      }
+      // end of switch symbol
+      if (!selectorRecursion) {
+        break;
+      }
+      if (!match) {
+        emit('\'' + selectorString + '\'' + qsInvalid);
+        return '';
+      }
+
+      // pop last component
+      selector = match.pop();
+    }
+    // end of while selector
+
+    return source;
+  };
+
+  // compile groups or single selector strings into
+  // executable functions for matching or selecting
+  const compile = function (selector, mode, callback) {
+    let head = ''; let loop = ''; let macro = ''; let source = ''; let vars = '';
+
+    // 'mode' can be boolean or null
+    // true = select / false = match
+    // null to use collection.item()
+    switch (mode) {
+      case true:
+        if (selectLambdas[selector]) {
+          return selectLambdas[selector];
+        }
+        macro = S_BODY + (callback ? S_TEST : '') + S_TAIL;
+        head = S_HEAD;
+        loop = S_LOOP;
+        break;
+      case false:
+        if (matchLambdas[selector]) {
+          return matchLambdas[selector];
+        }
+        macro = M_BODY + (callback ? M_TEST : '') + M_TAIL;
+        head = M_HEAD;
+        loop = M_LOOP;
+        break;
+      case null:
+        if (selectLambdas[selector]) {
+          return selectLambdas[selector];
+        }
+        macro = N_BODY + (callback ? N_TEST : '') + S_TAIL;
+        head = S_HEAD;
+        loop = N_LOOP;
+        break;
+      default:
+    }
+
+    source = compileSelector(selector, macro, mode, callback);
+
+    loop += (mode || mode === null) ? '{' + source + '}' : source;
+
+    if ((mode || mode === null) && selector.includes(':nth')) {
+      loop += reNthElem.test(selector) ? 's.nthElement(null, 2);' : '';
+      loop += reNthType.test(selector) ? 's.nthOfType(null, 2);' : '';
+    }
+
+    if (S_VARS[0] || M_VARS[0]) {
+      vars = ',' + (S_VARS.join(',') || M_VARS.join(','));
+      S_VARS = [];
+      M_VARS = [];
+    }
+
+    const factory = Function('s', F_INIT + '{' + head + vars + ';' + loop + 'return r;}')(Snapshot);
+
+    return mode || mode === null ? (selectLambdas[selector] = factory) : (matchLambdas[selector] = factory);
+  };
+
+  // optimize selectors avoiding duplicated checks
+  const optimize = function (selector, token) {
+    const index = token.index;
+    const length = token[1].length + token[2].length;
+    return selector.slice(0, index) +
+      (' >+~'.indexOf(selector.charAt(index - 1)) > -1
+        ? (':['.indexOf(selector.charAt(index + length + 1)) > -1
+            ? '*'
+            : '')
+        : '') + selector.slice(index + length - (token[1] === '*' ? 1 : 0));
+  };
+
+  // prepare factory resolvers and closure collections
+  const collect = function (selectors, context, callback) {
+    let i;
+    let l;
+    const seen = { };
+    let token = ['', '*', '*'];
+    const optimized = selectors;
+    const factory = [];
+    const htmlset = [];
+    const nodeset = [];
+    let results = [];
+    let type;
+
+    for (i = 0, l = selectors.length; l > i; ++i) {
+      if (!seen[selectors[i]] && (seen[selectors[i]] = true)) {
+        type = selectors[i].match(reOptimizer);
+        if (type && type[1] !== ':' && (token = type)) {
+          token[1] || (token[1] = '*');
+          optimized[i] = optimize(optimized[i], token);
+        } else {
+          token = ['', '*', '*'];
+        }
+      }
+
+      nodeset[i] = token[1] + token[2];
+      htmlset[i] = compat[token[1]](context, token[2]);
+      factory[i] = compile(optimized[i], true, null);
+
+      factory[i]
+        ? factory[i](htmlset[i](), callback, context, results)
+        : results.concat(htmlset[i]());
+    }
+
+    if (l > 1) {
+      results.sort(documentOrder);
+      hasDupes && (results = unique(results));
+    }
+
+    return {
+      callback,
+      context,
+      factory,
+      htmlset,
+      nodeset,
+      results
+    };
+  };
+
+  // replace ':scope' pseudo-class with element references
+  const makeref = function (selectors, element) {
+    // DOCUMENT_NODE (9)
+    if (element.nodeType === 9) {
+      element = element.documentElement;
+    }
+
+    return selectors.replace(/:scope/gi,
+      element.localName +
+        (element.id ? '#' + element.id : '') +
+        (element.className ? '.' + element.classList[0] : ''));
+  };
+
+  const matchAssert = function (f, element, callback) {
+    let r = false;
+    for (let i = 0, l = f.length; l > i; ++i) {
+      f[i](element, callback, null, false) && (r = true);
+    }
+    return r;
+  };
+
+  const matchCollect = function (selectors, callback) {
+    const f = [];
+    for (let i = 0, l = selectors.length; l > i; ++i) {
+      f[i] = compile(selectors[i], false, callback);
+    }
+    return { factory: f };
+  };
+
+  // equivalent of w3c 'matches' method
+  const match = function _matches(selectors, element, callback) {
+    let expressions;
+
+    if (element && !/:has\(/.test(selectors) && matchResolvers[selectors]) {
+      return matchAssert(matchResolvers[selectors].factory, element, callback);
+    }
+
+    lastMatched = selectors;
+
+    // arguments validation
+    if (arguments.length === 0) {
+      emit(qsNotArgs, 'TypeError');
+      return Config.VERBOSITY ? undefined : false;
+    } else if (arguments[0] === '') {
+      emit('\'\'' + qsInvalid);
+      return Config.VERBOSITY ? undefined : false;
+    }
+
+    // input NULL or UNDEFINED
+    if (typeof selectors !== 'string') {
+      selectors = '' + selectors;
+    }
+
+    if ((/:scope/i).test(selectors)) {
+      selectors = makeref(selectors, element);
+    }
+
+    // normalize input string
+    const parsed = selectors
+      .replace(/\0|\\$/g, '\ufffd')
+      .replace(REX.combineWSP, '\x20')
+      .replace(REX.pseudosWSP, '$1')
+      .replace(REX.tabCharWSP, '\t')
+      .replace(REX.commaGroup, ',')
+      .replace(REX.trimSpaces, '');
+
+    // parse, validate and split possible compound selectors
+    if ((expressions = parsed.match(reValidator)) && expressions.join('') === parsed) {
+      expressions = parsed.match(REX.splitGroup);
+      if (parsed[parsed.length - 1] === ',') {
+        emit(qsInvalid);
+        return Config.VERBOSITY ? undefined : false;
+      }
+    } else {
+      emit('\'' + selectors + '\'' + qsInvalid);
+      return Config.VERBOSITY ? undefined : false;
+    }
+
+    matchResolvers[selectors] = matchCollect(expressions, callback);
+
+    return matchAssert(matchResolvers[selectors].factory, element, callback);
+  };
+
+  // equivalent of w3c 'closest' method
+  const ancestor = function _closest(selectors, element, callback) {
+    if ((/:scope/i).test(selectors)) {
+      selectors = makeref(selectors, element);
+    }
+
+    while (element) {
+      if (match(selectors, element, callback)) break;
+      element = element.parentElement;
+    }
+    return element;
+  };
+
+  // equivalent of w3c 'querySelectorAll' method
+  const select = function _querySelectorAll(selectors, context, callback) {
+    let expressions; let nodes = []; let resolver;
+
+    context || (context = doc);
+
+    if (selectors) {
+      if ((resolver = selectResolvers[selectors])) {
+        if (resolver.context === context && resolver.callback === callback) {
+          const f = resolver.factory;
+          const h = resolver.htmlset;
+          const n = resolver.nodeset;
+          if (n.length > 1) {
+            const l = n.length;
+            for (let i = 0, l = n.length, list; l > i; ++i) {
+              list = compat[n[i][0]](context, n[i].slice(1))();
+              if (f[i] !== null) {
+                f[i](list, callback, context, nodes);
+              } else {
+                nodes = nodes.concat(list);
+              }
+            }
+            if (l > 1 && nodes.length > 1) {
+              nodes.sort(documentOrder);
+              hasDupes && (nodes = unique(nodes));
+            }
+          } else {
+            if (f[0]) {
+              nodes = f[0](h[0](), callback, context, nodes);
+            } else {
+              nodes = h[0]();
+            }
+          }
+          return typeof callback === 'function'
+            ? concatCall(nodes, callback)
+            : nodes;
+        }
+      }
+    }
+
+    lastSelected = selectors;
+
+    // arguments validation
+    if (arguments.length === 0) {
+      emit(qsNotArgs, 'TypeError');
+      return Config.VERBOSITY ? undefined : none;
+    } else if (arguments[0] === '') {
+      emit('\'\'' + qsInvalid);
+      return Config.VERBOSITY ? undefined : none;
+    } else if (lastContext !== context) {
+      lastContext = switchContext(context);
+    }
+
+    // input NULL or UNDEFINED
+    if (typeof selectors !== 'string') {
+      selectors = '' + selectors;
+    }
+
+    if ((/:scope/i).test(selectors)) {
+      selectors = makeref(selectors, context);
+    }
+
+    // normalize input string
+    const parsed = selectors
+      .replace(/\0|\\$/g, '\ufffd')
+      .replace(REX.combineWSP, '\x20')
+      .replace(REX.pseudosWSP, '$1')
+      .replace(REX.tabCharWSP, '\t')
+      .replace(REX.commaGroup, ',')
+      .replace(REX.trimSpaces, '');
+
+    // parse, validate and split possible compound selectors
+    if ((expressions = parsed.match(reValidator)) && expressions.join('') === parsed) {
+      expressions = parsed.match(REX.splitGroup);
+      if (parsed[parsed.length - 1] === ',') {
+        emit(qsInvalid);
+        return Config.VERBOSITY ? undefined : false;
+      }
+    } else {
+      emit('\'' + selectors + '\'' + qsInvalid);
+      return Config.VERBOSITY ? undefined : false;
+    }
+
+    // save/reuse factory and closure collection
+    selectResolvers[selectors] = collect(expressions, context, callback);
+
+    nodes = selectResolvers[selectors].results;
+
+    return typeof callback === 'function'
+      ? concatCall(nodes, callback)
+      : nodes;
+  };
+
+  // equivalent of w3c 'querySelector' method
+  const first = function _querySelector(selectors, context, callback) {
+    if (arguments.length === 0) {
+      emit(qsNotArgs, 'TypeError');
+    }
+    return select(selectors, context, typeof callback === 'function'
+      ? function firstMatch(element) {
+        callback(element);
+        return false;
+      }
+      : function firstMatch() {
+        return false;
+      }
+    )[0] || null;
+  };
+
+  // execute the engine initialization code
+  const initialize = function (d) {
+    setIdentifierSyntax();
+    lastContext = switchContext(d, true);
+    Snapshot.doc = doc;
+    Snapshot.from = doc;
+    Snapshot.byTag = byTag;
+    Snapshot.first = first;
+    Snapshot.match = match;
+    Snapshot.ancestor = ancestor;
+    Snapshot.nthOfType = nthOfType;
+    Snapshot.nthElement = nthElement;
+    Snapshot.hasAttributeNS = hasAttributeNS;
+    Snapshot.isTarget = isTarget;
+    Snapshot.isIndeterminate = isIndeterminate;
+    Snapshot.isContentEditable = isContentEditable;
+  };
+
+  initialize(doc);
+
+  // public exported methods/objects
+  const Dom = {
+    // exported engine methods
+    Version: version,
+    configure,
+    match,
+    closest: ancestor,
+    first,
+    select
+  };
+
+  return Dom;
+});