Complete Email Sortierer implementation with Appwrite and Stripe integration

server/node_modules/@asamuzakjp/dom-selector/src/index.js

@@ -0,0 +1,353 @@
+/*!
+ * DOM Selector - A CSS selector engine.
+ * @license MIT
+ * @copyright asamuzaK (Kazz)
+ * @see {@link https://github.com/asamuzaK/domSelector/blob/main/LICENSE}
+ */
+
+/* import */
+import { LRUCache } from 'lru-cache';
+import { Finder } from './js/finder.js';
+import { filterSelector, getType, initNwsapi } from './js/utility.js';
+
+/* constants */
+import {
+  DOCUMENT_NODE,
+  DOCUMENT_FRAGMENT_NODE,
+  ELEMENT_NODE,
+  TARGET_ALL,
+  TARGET_FIRST,
+  TARGET_LINEAL,
+  TARGET_SELF
+} from './js/constant.js';
+const MAX_CACHE = 1024;
+
+/**
+ * @typedef {object} CheckResult
+ * @property {boolean} match - The match result.
+ * @property {string?} pseudoElement - The pseudo-element, if any.
+ */
+
+/* DOMSelector */
+export class DOMSelector {
+  /* private fields */
+  #window;
+  #document;
+  #finder;
+  #idlUtils;
+  #nwsapi;
+  #cache;
+
+  /**
+   * Creates an instance of DOMSelector.
+   * @param {Window} window - The window object.
+   * @param {Document} document - The document object.
+   * @param {object} [opt] - Options.
+   */
+  constructor(window, document, opt = {}) {
+    const { idlUtils } = opt;
+    this.#window = window;
+    this.#document = document ?? window.document;
+    this.#finder = new Finder(window);
+    this.#idlUtils = idlUtils;
+    this.#nwsapi = initNwsapi(window, document);
+    this.#cache = new LRUCache({
+      max: MAX_CACHE
+    });
+  }
+
+  /**
+   * Clears the internal cache of finder results.
+   * @returns {void}
+   */
+  clear = () => {
+    this.#finder.clearResults(true);
+  };
+
+  /**
+   * Checks if an element matches a CSS selector.
+   * @param {string} selector - The CSS selector to check against.
+   * @param {Element} node - The element node to check.
+   * @param {object} [opt] - Optional parameters.
+   * @returns {CheckResult} An object containing the check result.
+   */
+  check = (selector, node, opt = {}) => {
+    if (!node?.nodeType) {
+      const e = new this.#window.TypeError(`Unexpected type ${getType(node)}`);
+      return this.#finder.onError(e, opt);
+    } else if (node.nodeType !== ELEMENT_NODE) {
+      const e = new this.#window.TypeError(`Unexpected node ${node.nodeName}`);
+      return this.#finder.onError(e, opt);
+    }
+    const document = node.ownerDocument;
+    if (
+      document === this.#document &&
+      document.contentType === 'text/html' &&
+      document.documentElement &&
+      node.parentNode
+    ) {
+      const cacheKey = `check_${selector}`;
+      let filterMatches = false;
+      if (this.#cache.has(cacheKey)) {
+        filterMatches = this.#cache.get(cacheKey);
+      } else {
+        filterMatches = filterSelector(selector, TARGET_SELF);
+        this.#cache.set(cacheKey, filterMatches);
+      }
+      if (filterMatches) {
+        try {
+          const n = this.#idlUtils ? this.#idlUtils.wrapperForImpl(node) : node;
+          const match = this.#nwsapi.match(selector, n);
+          return {
+            match,
+            pseudoElement: null
+          };
+        } catch (e) {
+          // fall through
+        }
+      }
+    }
+    let res;
+    try {
+      if (this.#idlUtils) {
+        node = this.#idlUtils.wrapperForImpl(node);
+      }
+      opt.check = true;
+      opt.noexept = true;
+      opt.warn = false;
+      this.#finder.setup(selector, node, opt);
+      res = this.#finder.find(TARGET_SELF);
+    } catch (e) {
+      this.#finder.onError(e, opt);
+    }
+    return res;
+  };
+
+  /**
+   * Returns true if the element matches the selector.
+   * @param {string} selector - The CSS selector to match against.
+   * @param {Element} node - The element node to test.
+   * @param {object} [opt] - Optional parameters.
+   * @returns {boolean} `true` if the element matches, or `false` otherwise.
+   */
+  matches = (selector, node, opt = {}) => {
+    if (!node?.nodeType) {
+      const e = new this.#window.TypeError(`Unexpected type ${getType(node)}`);
+      return this.#finder.onError(e, opt);
+    } else if (node.nodeType !== ELEMENT_NODE) {
+      const e = new this.#window.TypeError(`Unexpected node ${node.nodeName}`);
+      return this.#finder.onError(e, opt);
+    }
+    const document = node.ownerDocument;
+    if (
+      document === this.#document &&
+      document.contentType === 'text/html' &&
+      document.documentElement &&
+      node.parentNode
+    ) {
+      const cacheKey = `matches_${selector}`;
+      let filterMatches = false;
+      if (this.#cache.has(cacheKey)) {
+        filterMatches = this.#cache.get(cacheKey);
+      } else {
+        filterMatches = filterSelector(selector, TARGET_SELF);
+        this.#cache.set(cacheKey, filterMatches);
+      }
+      if (filterMatches) {
+        try {
+          const n = this.#idlUtils ? this.#idlUtils.wrapperForImpl(node) : node;
+          const res = this.#nwsapi.match(selector, n);
+          return res;
+        } catch (e) {
+          // fall through
+        }
+      }
+    }
+    let res;
+    try {
+      if (this.#idlUtils) {
+        node = this.#idlUtils.wrapperForImpl(node);
+      }
+      this.#finder.setup(selector, node, opt);
+      const nodes = this.#finder.find(TARGET_SELF);
+      res = nodes.size;
+    } catch (e) {
+      this.#finder.onError(e, opt);
+    }
+    return !!res;
+  };
+
+  /**
+   * Traverses up the DOM tree to find the first node that matches the selector.
+   * @param {string} selector - The CSS selector to match against.
+   * @param {Element} node - The element from which to start traversing.
+   * @param {object} [opt] - Optional parameters.
+   * @returns {?Element} The first matching ancestor element, or `null`.
+   */
+  closest = (selector, node, opt = {}) => {
+    if (!node?.nodeType) {
+      const e = new this.#window.TypeError(`Unexpected type ${getType(node)}`);
+      return this.#finder.onError(e, opt);
+    } else if (node.nodeType !== ELEMENT_NODE) {
+      const e = new this.#window.TypeError(`Unexpected node ${node.nodeName}`);
+      return this.#finder.onError(e, opt);
+    }
+    const document = node.ownerDocument;
+    if (
+      document === this.#document &&
+      document.contentType === 'text/html' &&
+      document.documentElement &&
+      node.parentNode
+    ) {
+      const cacheKey = `closest_${selector}`;
+      let filterMatches = false;
+      if (this.#cache.has(cacheKey)) {
+        filterMatches = this.#cache.get(cacheKey);
+      } else {
+        filterMatches = filterSelector(selector, TARGET_LINEAL);
+        this.#cache.set(cacheKey, filterMatches);
+      }
+      if (filterMatches) {
+        try {
+          const n = this.#idlUtils ? this.#idlUtils.wrapperForImpl(node) : node;
+          const res = this.#nwsapi.closest(selector, n);
+          return res;
+        } catch (e) {
+          // fall through
+        }
+      }
+    }
+    let res;
+    try {
+      if (this.#idlUtils) {
+        node = this.#idlUtils.wrapperForImpl(node);
+      }
+      this.#finder.setup(selector, node, opt);
+      const nodes = this.#finder.find(TARGET_LINEAL);
+      if (nodes.size) {
+        let refNode = node;
+        while (refNode) {
+          if (nodes.has(refNode)) {
+            res = refNode;
+            break;
+          }
+          refNode = refNode.parentNode;
+        }
+      }
+    } catch (e) {
+      this.#finder.onError(e, opt);
+    }
+    return res ?? null;
+  };
+
+  /**
+   * Returns the first element within the subtree that matches the selector.
+   * @param {string} selector - The CSS selector to match.
+   * @param {Document|DocumentFragment|Element} node - The node to find within.
+   * @param {object} [opt] - Optional parameters.
+   * @returns {?Element} The first matching element, or `null`.
+   */
+  querySelector = (selector, node, opt = {}) => {
+    if (!node?.nodeType) {
+      const e = new this.#window.TypeError(`Unexpected type ${getType(node)}`);
+      return this.#finder.onError(e, opt);
+    }
+    /*
+    const document =
+      node.nodeType === DOCUMENT_NODE ? node : node.ownerDocument;
+    if (
+      document === this.#document &&
+      document.contentType === 'text/html' &&
+      document.documentElement &&
+      (node.nodeType !== DOCUMENT_FRAGMENT_NODE || !node.host)
+    ) {
+      const cacheKey = `querySelector_${selector}`;
+      let filterMatches = false;
+      if (this.#cache.has(cacheKey)) {
+        filterMatches = this.#cache.get(cacheKey);
+      } else {
+        filterMatches = filterSelector(selector, TARGET_FIRST);
+        this.#cache.set(cacheKey, filterMatches);
+      }
+      if (filterMatches) {
+        try {
+          const n = this.#idlUtils ? this.#idlUtils.wrapperForImpl(node) : node;
+          const res = this.#nwsapi.first(selector, n);
+          return res;
+        } catch (e) {
+          // fall through
+        }
+      }
+    }
+    */
+    let res;
+    try {
+      if (this.#idlUtils) {
+        node = this.#idlUtils.wrapperForImpl(node);
+      }
+      this.#finder.setup(selector, node, opt);
+      const nodes = this.#finder.find(TARGET_FIRST);
+      if (nodes.size) {
+        [res] = [...nodes];
+      }
+    } catch (e) {
+      this.#finder.onError(e, opt);
+    }
+    return res ?? null;
+  };
+
+  /**
+   * Returns an array of elements within the subtree that match the selector.
+   * Note: This method returns an Array, not a NodeList.
+   * @param {string} selector - The CSS selector to match.
+   * @param {Document|DocumentFragment|Element} node - The node to find within.
+   * @param {object} [opt] - Optional parameters.
+   * @returns {Array<Element>} An array of elements, or an empty array.
+   */
+  querySelectorAll = (selector, node, opt = {}) => {
+    if (!node?.nodeType) {
+      const e = new this.#window.TypeError(`Unexpected type ${getType(node)}`);
+      return this.#finder.onError(e, opt);
+    }
+    const document =
+      node.nodeType === DOCUMENT_NODE ? node : node.ownerDocument;
+    if (
+      document === this.#document &&
+      document.contentType === 'text/html' &&
+      document.documentElement &&
+      (node.nodeType !== DOCUMENT_FRAGMENT_NODE || !node.host)
+    ) {
+      const cacheKey = `querySelectorAll_${selector}`;
+      let filterMatches = false;
+      if (this.#cache.has(cacheKey)) {
+        filterMatches = this.#cache.get(cacheKey);
+      } else {
+        filterMatches = filterSelector(selector, TARGET_ALL);
+        this.#cache.set(cacheKey, filterMatches);
+      }
+      if (filterMatches) {
+        try {
+          const n = this.#idlUtils ? this.#idlUtils.wrapperForImpl(node) : node;
+          const res = this.#nwsapi.select(selector, n);
+          return res;
+        } catch (e) {
+          // fall through
+        }
+      }
+    }
+    let res;
+    try {
+      if (this.#idlUtils) {
+        node = this.#idlUtils.wrapperForImpl(node);
+      }
+      this.#finder.setup(selector, node, opt);
+      const nodes = this.#finder.find(TARGET_ALL);
+      if (nodes.size) {
+        res = [...nodes];
+      }
+    } catch (e) {
+      this.#finder.onError(e, opt);
+    }
+    return res ?? [];
+  };
+}

server/node_modules/@asamuzakjp/dom-selector/src/js/constant.js

@@ -0,0 +1,129 @@
+/**
+ * constant.js
+ */
+
+/* string */
+export const ATRULE = 'Atrule';
+export const ATTR_SELECTOR = 'AttributeSelector';
+export const CLASS_SELECTOR = 'ClassSelector';
+export const COMBINATOR = 'Combinator';
+export const IDENT = 'Identifier';
+export const ID_SELECTOR = 'IdSelector';
+export const NOT_SUPPORTED_ERR = 'NotSupportedError';
+export const NTH = 'Nth';
+export const OPERATOR = 'Operator';
+export const PS_CLASS_SELECTOR = 'PseudoClassSelector';
+export const PS_ELEMENT_SELECTOR = 'PseudoElementSelector';
+export const RULE = 'Rule';
+export const SCOPE = 'Scope';
+export const SELECTOR = 'Selector';
+export const SELECTOR_LIST = 'SelectorList';
+export const STRING = 'String';
+export const SYNTAX_ERR = 'SyntaxError';
+export const TARGET_ALL = 'all';
+export const TARGET_FIRST = 'first';
+export const TARGET_LINEAL = 'lineal';
+export const TARGET_SELF = 'self';
+export const TYPE_SELECTOR = 'TypeSelector';
+
+/* numeric */
+export const BIT_01 = 1;
+export const BIT_02 = 2;
+export const BIT_04 = 4;
+export const BIT_08 = 8;
+export const BIT_16 = 0x10;
+export const BIT_32 = 0x20;
+export const BIT_FFFF = 0xffff;
+export const DUO = 2;
+export const HEX = 16;
+export const TYPE_FROM = 8;
+export const TYPE_TO = -1;
+
+/* Node */
+export const ELEMENT_NODE = 1;
+export const TEXT_NODE = 3;
+export const DOCUMENT_NODE = 9;
+export const DOCUMENT_FRAGMENT_NODE = 11;
+export const DOCUMENT_POSITION_PRECEDING = 2;
+export const DOCUMENT_POSITION_CONTAINS = 8;
+export const DOCUMENT_POSITION_CONTAINED_BY = 0x10;
+
+/* NodeFilter */
+export const SHOW_ALL = 0xffffffff;
+export const SHOW_CONTAINER = 0x501;
+export const SHOW_DOCUMENT = 0x100;
+export const SHOW_DOCUMENT_FRAGMENT = 0x400;
+export const SHOW_ELEMENT = 1;
+
+/* selectors */
+export const ALPHA_NUM = '[A-Z\\d]+';
+export const CHILD_IDX = '(?:first|last|only)-(?:child|of-type)';
+export const DIGIT = '(?:0|[1-9]\\d*)';
+export const LANG_PART = `(?:-${ALPHA_NUM})*`;
+export const PSEUDO_CLASS = `(?:any-)?link|${CHILD_IDX}|checked|empty|indeterminate|read-(?:only|write)|target`;
+export const ANB = `[+-]?(?:${DIGIT}n?|n)|(?:[+-]?${DIGIT})?n\\s*[+-]\\s*${DIGIT}`;
+// combinators
+export const COMBO = '\\s?[\\s>~+]\\s?';
+export const DESCEND = '\\s?[\\s>]\\s?';
+export const SIBLING = '\\s?[+~]\\s?';
+// LOGIC_IS: :is()
+export const LOGIC_IS = `:is\\(\\s*[^)]+\\s*\\)`;
+// N_TH: excludes An+B with selector list, e.g. :nth-child(2n+1 of .foo)
+export const N_TH = `nth-(?:last-)?(?:child|of-type)\\(\\s*(?:even|odd|${ANB})\\s*\\)`;
+// SUB_TYPE: attr, id, class, pseudo-class, note that [foo|=bar] is excluded
+export const SUB_TYPE = '\\[[^|\\]]+\\]|[#.:][\\w-]+';
+export const SUB_TYPE_WO_PSEUDO = '\\[[^|\\]]+\\]|[#.][\\w-]+';
+// TAG_TYPE: *, tag
+export const TAG_TYPE = '\\*|[A-Za-z][\\w-]*';
+export const TAG_TYPE_I = '\\*|[A-Z][\\w-]*';
+export const COMPOUND = `(?:${TAG_TYPE}|(?:${TAG_TYPE})?(?:${SUB_TYPE})+)`;
+export const COMPOUND_L = `(?:${TAG_TYPE}|(?:${TAG_TYPE})?(?:${SUB_TYPE}|${LOGIC_IS})+)`;
+export const COMPOUND_I = `(?:${TAG_TYPE_I}|(?:${TAG_TYPE_I})?(?:${SUB_TYPE})+)`;
+export const COMPOUND_WO_PSEUDO = `(?:${TAG_TYPE}|(?:${TAG_TYPE})?(?:${SUB_TYPE_WO_PSEUDO})+)`;
+export const COMPLEX = `${COMPOUND}(?:${COMBO}${COMPOUND})*`;
+export const COMPLEX_L = `${COMPOUND_L}(?:${COMBO}${COMPOUND_L})*`;
+export const HAS_COMPOUND = `has\\([\\s>]?\\s*${COMPOUND_WO_PSEUDO}\\s*\\)`;
+export const LOGIC_COMPOUND = `(?:is|not)\\(\\s*${COMPOUND_L}(?:\\s*,\\s*${COMPOUND_L})*\\s*\\)`;
+export const LOGIC_COMPLEX = `(?:is|not)\\(\\s*${COMPLEX_L}(?:\\s*,\\s*${COMPLEX_L})*\\s*\\)`;
+
+/* forms and input types */
+export const FORM_PARTS = Object.freeze([
+  'button',
+  'input',
+  'select',
+  'textarea'
+]);
+export const INPUT_BUTTON = Object.freeze(['button', 'reset', 'submit']);
+export const INPUT_CHECK = Object.freeze(['checkbox', 'radio']);
+export const INPUT_DATE = Object.freeze([
+  'date',
+  'datetime-local',
+  'month',
+  'time',
+  'week'
+]);
+export const INPUT_TEXT = Object.freeze([
+  'email',
+  'password',
+  'search',
+  'tel',
+  'text',
+  'url'
+]);
+export const INPUT_EDIT = Object.freeze([
+  ...INPUT_DATE,
+  ...INPUT_TEXT,
+  'number'
+]);
+export const INPUT_LTR = Object.freeze([
+  ...INPUT_CHECK,
+  'color',
+  'date',
+  'image',
+  'number',
+  'range',
+  'time'
+]);
+
+/* logical combination pseudo-classes */
+export const KEYS_LOGICAL = new Set(['has', 'is', 'not', 'where']);

server/node_modules/@asamuzakjp/dom-selector/src/js/matcher.js

@@ -0,0 +1,587 @@
+/**
+ * matcher.js
+ */
+
+/* import */
+import { generateCSS, parseAstName, unescapeSelector } from './parser.js';
+import {
+  generateException,
+  getDirectionality,
+  getLanguageAttribute,
+  getType,
+  isContentEditable,
+  isCustomElement,
+  isNamespaceDeclared
+} from './utility.js';
+
+/* constants */
+import {
+  ALPHA_NUM,
+  FORM_PARTS,
+  IDENT,
+  INPUT_EDIT,
+  LANG_PART,
+  NOT_SUPPORTED_ERR,
+  PS_ELEMENT_SELECTOR,
+  STRING,
+  SYNTAX_ERR
+} from './constant.js';
+const KEYS_FORM_PS_DISABLED = new Set([
+  ...FORM_PARTS,
+  'fieldset',
+  'optgroup',
+  'option'
+]);
+const KEYS_INPUT_EDIT = new Set(INPUT_EDIT);
+const REG_LANG_VALID = new RegExp(`^(?:\\*-)?${ALPHA_NUM}${LANG_PART}$`, 'i');
+const REG_TAG_NAME = /[A-Z][\\w-]*/i;
+
+/**
+ * Validates a pseudo-element selector.
+ * @param {string} astName - The name of the pseudo-element from the AST.
+ * @param {string} astType - The type of the selector from the AST.
+ * @param {object} [opt] - Optional parameters.
+ * @param {boolean} [opt.forgive] - If true, ignores unknown pseudo-elements.
+ * @param {boolean} [opt.warn] - If true, throws an error for unsupported ones.
+ * @throws {DOMException} If the selector is invalid or unsupported.
+ * @returns {void}
+ */
+export const matchPseudoElementSelector = (astName, astType, opt = {}) => {
+  const { forgive, globalObject, warn } = opt;
+  if (astType !== PS_ELEMENT_SELECTOR) {
+    // Ensure the AST node is a pseudo-element selector.
+    throw new TypeError(`Unexpected ast type ${getType(astType)}`);
+  }
+  switch (astName) {
+    case 'after':
+    case 'backdrop':
+    case 'before':
+    case 'cue':
+    case 'cue-region':
+    case 'first-letter':
+    case 'first-line':
+    case 'file-selector-button':
+    case 'marker':
+    case 'placeholder':
+    case 'selection':
+    case 'target-text': {
+      // Warn if the pseudo-element is known but unsupported.
+      if (warn) {
+        throw generateException(
+          `Unsupported pseudo-element ::${astName}`,
+          NOT_SUPPORTED_ERR,
+          globalObject
+        );
+      }
+      break;
+    }
+    case 'part':
+    case 'slotted': {
+      // Warn if the functional pseudo-element is known but unsupported.
+      if (warn) {
+        throw generateException(
+          `Unsupported pseudo-element ::${astName}()`,
+          NOT_SUPPORTED_ERR,
+          globalObject
+        );
+      }
+      break;
+    }
+    default: {
+      // Handle vendor-prefixed or unknown pseudo-elements.
+      if (astName.startsWith('-webkit-')) {
+        if (warn) {
+          throw generateException(
+            `Unsupported pseudo-element ::${astName}`,
+            NOT_SUPPORTED_ERR,
+            globalObject
+          );
+        }
+        // Throw an error for unknown pseudo-elements if not forgiven.
+      } else if (!forgive) {
+        throw generateException(
+          `Unknown pseudo-element ::${astName}`,
+          SYNTAX_ERR,
+          globalObject
+        );
+      }
+    }
+  }
+};
+
+/**
+ * Matches the :dir() pseudo-class against an element's directionality.
+ * @param {object} ast - The AST object for the pseudo-class.
+ * @param {object} node - The element node to match against.
+ * @throws {TypeError} If the AST does not contain a valid direction value.
+ * @returns {boolean} - True if the directionality matches, otherwise false.
+ */
+export const matchDirectionPseudoClass = (ast, node) => {
+  const { name } = ast;
+  // The :dir() pseudo-class requires a direction argument (e.g., "ltr").
+  if (!name) {
+    const type = name === '' ? '(empty String)' : getType(name);
+    throw new TypeError(`Unexpected ast type ${type}`);
+  }
+  // Get the computed directionality of the element.
+  const dir = getDirectionality(node);
+  // Compare the expected direction with the element's actual direction.
+  return name === dir;
+};
+
+/**
+ * Matches the :lang() pseudo-class against an element's language.
+ * @see https://datatracker.ietf.org/doc/html/rfc4647#section-3.3.1
+ * @param {object} ast - The AST object for the pseudo-class.
+ * @param {object} node - The element node to match against.
+ * @returns {boolean} - True if the language matches, otherwise false.
+ */
+export const matchLanguagePseudoClass = (ast, node) => {
+  const { name, type, value } = ast;
+  let langPattern;
+  // Determine the language pattern from the AST.
+  if (type === STRING && value) {
+    langPattern = value;
+  } else if (type === IDENT && name) {
+    langPattern = unescapeSelector(name);
+  }
+  // If no valid language pattern is provided, it cannot match.
+  if (typeof langPattern !== 'string') {
+    return false;
+  }
+  // Get the effective language attribute for the current node.
+  const elementLang = getLanguageAttribute(node);
+  // If the element has no language, it cannot match a specific pattern.
+  if (elementLang === null) {
+    return false;
+  }
+  // Handle the universal selector '*' for :lang.
+  if (langPattern === '*') {
+    // It matches any language unless attribute is not empty.
+    return elementLang !== '';
+  }
+  // Validate the provided language pattern structure.
+  if (!REG_LANG_VALID.test(langPattern)) {
+    return false;
+  }
+  // Build a regex for extended language range matching.
+  let matcherRegex;
+  if (langPattern.indexOf('-') > -1) {
+    // Handle complex patterns with wildcards and sub-tags (e.g., '*-US').
+    const [langMain, langSub, ...langRest] = langPattern.split('-');
+    const extendedMain =
+      langMain === '*' ? `${ALPHA_NUM}${LANG_PART}` : `${langMain}${LANG_PART}`;
+    const extendedSub = `-${langSub}${LANG_PART}`;
+    let extendedRest = '';
+    // Use a standard for loop for performance as per the rules.
+    for (let i = 0; i < langRest.length; i++) {
+      extendedRest += `-${langRest[i]}${LANG_PART}`;
+    }
+    matcherRegex = new RegExp(
+      `^${extendedMain}${extendedSub}${extendedRest}$`,
+      'i'
+    );
+  } else {
+    // Handle simple language patterns (e.g., 'en').
+    matcherRegex = new RegExp(`^${langPattern}${LANG_PART}$`, 'i');
+  }
+  // Test the element's language against the constructed regex.
+  return matcherRegex.test(elementLang);
+};
+
+/**
+ * Matches the :disabled and :enabled pseudo-classes.
+ * @param {string} astName - pseudo-class name
+ * @param {object} node - Element node
+ * @returns {boolean} - True if matched
+ */
+export const matchDisabledPseudoClass = (astName, node) => {
+  const { localName, parentNode } = node;
+  if (
+    !KEYS_FORM_PS_DISABLED.has(localName) &&
+    !isCustomElement(node, { formAssociated: true })
+  ) {
+    return false;
+  }
+  let isDisabled = false;
+  if (node.disabled || node.hasAttribute('disabled')) {
+    isDisabled = true;
+  } else if (localName === 'option') {
+    if (
+      parentNode &&
+      parentNode.localName === 'optgroup' &&
+      (parentNode.disabled || parentNode.hasAttribute('disabled'))
+    ) {
+      isDisabled = true;
+    }
+  } else if (localName !== 'optgroup') {
+    let current = parentNode;
+    while (current) {
+      if (
+        current.localName === 'fieldset' &&
+        (current.disabled || current.hasAttribute('disabled'))
+      ) {
+        // The first <legend> in a disabled <fieldset> is not disabled.
+        let legend;
+        let element = current.firstElementChild;
+        while (element) {
+          if (element.localName === 'legend') {
+            legend = element;
+            break;
+          }
+          element = element.nextElementSibling;
+        }
+        if (!legend || !legend.contains(node)) {
+          isDisabled = true;
+        }
+        // Found the containing fieldset, stop searching up.
+        break;
+      }
+      current = current.parentNode;
+    }
+  }
+  if (astName === 'disabled') {
+    return isDisabled;
+  }
+  return !isDisabled;
+};
+
+/**
+ * Match the :read-only and :read-write pseudo-classes
+ * @param {string} astName - pseudo-class name
+ * @param {object} node - Element node
+ * @returns {boolean} - True if matched
+ */
+export const matchReadOnlyPseudoClass = (astName, node) => {
+  const { localName } = node;
+  let isReadOnly = false;
+  switch (localName) {
+    case 'textarea':
+    case 'input': {
+      const isEditableInput = !node.type || KEYS_INPUT_EDIT.has(node.type);
+      if (localName === 'textarea' || isEditableInput) {
+        isReadOnly =
+          node.readOnly ||
+          node.hasAttribute('readonly') ||
+          node.disabled ||
+          node.hasAttribute('disabled');
+      } else {
+        // Non-editable input types are always read-only
+        isReadOnly = true;
+      }
+      break;
+    }
+    default: {
+      isReadOnly = !isContentEditable(node);
+    }
+  }
+  if (astName === 'read-only') {
+    return isReadOnly;
+  }
+  return !isReadOnly;
+};
+
+/**
+ * Matches an attribute selector against an element.
+ * This function handles various attribute matchers like '=', '~=', '^=', etc.,
+ * and considers namespaces and case sensitivity based on document type.
+ * @param {object} ast - The AST for the attribute selector.
+ * @param {object} node - The element node to match against.
+ * @param {object} [opt] - Optional parameters.
+ * @param {boolean} [opt.check] - True if running in an internal check.
+ * @param {boolean} [opt.forgive] - True to forgive certain syntax errors.
+ * @returns {boolean} - True if the attribute selector matches, otherwise false.
+ */
+export const matchAttributeSelector = (ast, node, opt = {}) => {
+  const {
+    flags: astFlags,
+    matcher: astMatcher,
+    name: astName,
+    value: astValue
+  } = ast;
+  const { check, forgive, globalObject } = opt;
+  // Validate selector flags ('i' or 's').
+  if (typeof astFlags === 'string' && !/^[is]$/i.test(astFlags) && !forgive) {
+    const css = generateCSS(ast);
+    throw generateException(
+      `Invalid selector ${css}`,
+      SYNTAX_ERR,
+      globalObject
+    );
+  }
+  const { attributes } = node;
+  // An element with no attributes cannot match.
+  if (!attributes || !attributes.length) {
+    return false;
+  }
+  // Determine case sensitivity based on document type and flags.
+  const contentType = node.ownerDocument.contentType;
+  let caseInsensitive;
+  if (contentType === 'text/html') {
+    if (typeof astFlags === 'string' && /^s$/i.test(astFlags)) {
+      caseInsensitive = false;
+    } else {
+      caseInsensitive = true;
+    }
+  } else if (typeof astFlags === 'string' && /^i$/i.test(astFlags)) {
+    caseInsensitive = true;
+  } else {
+    caseInsensitive = false;
+  }
+  // Prepare the attribute name from the selector for matching.
+  let astAttrName = unescapeSelector(astName.name);
+  if (caseInsensitive) {
+    astAttrName = astAttrName.toLowerCase();
+  }
+  // A set to store the values of attributes whose names match.
+  const attrValues = new Set();
+  // Handle namespaced attribute names (e.g., [*|attr], [ns|attr]).
+  if (astAttrName.indexOf('|') > -1) {
+    const { prefix: astPrefix, localName: astLocalName } =
+      parseAstName(astAttrName);
+    for (const item of attributes) {
+      let { name: itemName, value: itemValue } = item;
+      if (caseInsensitive) {
+        itemName = itemName.toLowerCase();
+        itemValue = itemValue.toLowerCase();
+      }
+      switch (astPrefix) {
+        case '': {
+          if (astLocalName === itemName) {
+            attrValues.add(itemValue);
+          }
+          break;
+        }
+        case '*': {
+          if (itemName.indexOf(':') > -1) {
+            const [, ...restItemName] = itemName.split(':');
+            const itemLocalName = restItemName.join(':').replace(/^:/, '');
+            if (itemLocalName === astLocalName) {
+              attrValues.add(itemValue);
+            }
+          } else if (astLocalName === itemName) {
+            attrValues.add(itemValue);
+          }
+          break;
+        }
+        default: {
+          if (!check) {
+            if (forgive) {
+              return false;
+            }
+            const css = generateCSS(ast);
+            throw generateException(
+              `Invalid selector ${css}`,
+              SYNTAX_ERR,
+              globalObject
+            );
+          }
+          if (itemName.indexOf(':') > -1) {
+            const [itemPrefix, ...restItemName] = itemName.split(':');
+            const itemLocalName = restItemName.join(':').replace(/^:/, '');
+            // Ignore the 'xml:lang' attribute.
+            if (itemPrefix === 'xml' && itemLocalName === 'lang') {
+              continue;
+            } else if (
+              astPrefix === itemPrefix &&
+              astLocalName === itemLocalName
+            ) {
+              const namespaceDeclared = isNamespaceDeclared(astPrefix, node);
+              if (namespaceDeclared) {
+                attrValues.add(itemValue);
+              }
+            }
+          }
+        }
+      }
+    }
+    // Handle non-namespaced attribute names.
+  } else {
+    for (let { name: itemName, value: itemValue } of attributes) {
+      if (caseInsensitive) {
+        itemName = itemName.toLowerCase();
+        itemValue = itemValue.toLowerCase();
+      }
+      if (itemName.indexOf(':') > -1) {
+        const [itemPrefix, ...restItemName] = itemName.split(':');
+        const itemLocalName = restItemName.join(':').replace(/^:/, '');
+        // The attribute is starting with ':'.
+        if (!itemPrefix && astAttrName === `:${itemLocalName}`) {
+          attrValues.add(itemValue);
+          // Ignore the 'xml:lang' attribute.
+        } else if (itemPrefix === 'xml' && itemLocalName === 'lang') {
+          continue;
+        } else if (astAttrName === itemLocalName) {
+          attrValues.add(itemValue);
+        }
+      } else if (astAttrName === itemName) {
+        attrValues.add(itemValue);
+      }
+    }
+  }
+  if (!attrValues.size) {
+    return false;
+  }
+  // Prepare the value from the selector's RHS for comparison.
+  const { name: astIdentValue, value: astStringValue } = astValue ?? {};
+  let attrValue;
+  if (astIdentValue) {
+    if (caseInsensitive) {
+      attrValue = astIdentValue.toLowerCase();
+    } else {
+      attrValue = astIdentValue;
+    }
+  } else if (astStringValue) {
+    if (caseInsensitive) {
+      attrValue = astStringValue.toLowerCase();
+    } else {
+      attrValue = astStringValue;
+    }
+  } else if (astStringValue === '') {
+    attrValue = astStringValue;
+  }
+  // Perform the final match based on the specified matcher.
+  switch (astMatcher) {
+    case '=': {
+      return typeof attrValue === 'string' && attrValues.has(attrValue);
+    }
+    case '~=': {
+      if (attrValue && typeof attrValue === 'string') {
+        for (const value of attrValues) {
+          const item = new Set(value.split(/\s+/));
+          if (item.has(attrValue)) {
+            return true;
+          }
+        }
+      }
+      return false;
+    }
+    case '|=': {
+      if (attrValue && typeof attrValue === 'string') {
+        for (const value of attrValues) {
+          if (value === attrValue || value.startsWith(`${attrValue}-`)) {
+            return true;
+          }
+        }
+      }
+      return false;
+    }
+    case '^=': {
+      if (attrValue && typeof attrValue === 'string') {
+        for (const value of attrValues) {
+          if (value.startsWith(`${attrValue}`)) {
+            return true;
+          }
+        }
+      }
+      return false;
+    }
+    case '$=': {
+      if (attrValue && typeof attrValue === 'string') {
+        for (const value of attrValues) {
+          if (value.endsWith(`${attrValue}`)) {
+            return true;
+          }
+        }
+      }
+      return false;
+    }
+    case '*=': {
+      if (attrValue && typeof attrValue === 'string') {
+        for (const value of attrValues) {
+          if (value.includes(`${attrValue}`)) {
+            return true;
+          }
+        }
+      }
+      return false;
+    }
+    case null:
+    default: {
+      // This case handles attribute existence checks (e.g., '[disabled]').
+      return true;
+    }
+  }
+};
+
+/**
+ * match type selector
+ * @param {object} ast - AST
+ * @param {object} node - Element node
+ * @param {object} [opt] - options
+ * @param {boolean} [opt.check] - running in internal check()
+ * @param {boolean} [opt.forgive] - forgive undeclared namespace
+ * @returns {boolean} - result
+ */
+export const matchTypeSelector = (ast, node, opt = {}) => {
+  const astName = unescapeSelector(ast.name);
+  const { localName, namespaceURI, prefix } = node;
+  const { check, forgive, globalObject } = opt;
+  let { prefix: astPrefix, localName: astLocalName } = parseAstName(
+    astName,
+    node
+  );
+  if (
+    node.ownerDocument.contentType === 'text/html' &&
+    (!namespaceURI || namespaceURI === 'http://www.w3.org/1999/xhtml') &&
+    REG_TAG_NAME.test(localName)
+  ) {
+    astPrefix = astPrefix.toLowerCase();
+    astLocalName = astLocalName.toLowerCase();
+  }
+  let nodePrefix;
+  let nodeLocalName;
+  // just in case that the namespaced content is parsed as text/html
+  if (localName.indexOf(':') > -1) {
+    [nodePrefix, nodeLocalName] = localName.split(':');
+  } else {
+    nodePrefix = prefix || '';
+    nodeLocalName = localName;
+  }
+  switch (astPrefix) {
+    case '': {
+      if (
+        !nodePrefix &&
+        !namespaceURI &&
+        (astLocalName === '*' || astLocalName === nodeLocalName)
+      ) {
+        return true;
+      }
+      return false;
+    }
+    case '*': {
+      if (astLocalName === '*' || astLocalName === nodeLocalName) {
+        return true;
+      }
+      return false;
+    }
+    default: {
+      if (!check) {
+        if (forgive) {
+          return false;
+        }
+        const css = generateCSS(ast);
+        throw generateException(
+          `Invalid selector ${css}`,
+          SYNTAX_ERR,
+          globalObject
+        );
+      }
+      const astNS = node.lookupNamespaceURI(astPrefix);
+      const nodeNS = node.lookupNamespaceURI(nodePrefix);
+      if (astNS === nodeNS && astPrefix === nodePrefix) {
+        if (astLocalName === '*' || astLocalName === nodeLocalName) {
+          return true;
+        }
+        return false;
+      } else if (!forgive && !astNS) {
+        throw generateException(
+          `Undeclared namespace ${astPrefix}`,
+          SYNTAX_ERR,
+          globalObject
+        );
+      }
+      return false;
+    }
+  }
+};

server/node_modules/@asamuzakjp/dom-selector/src/js/parser.js

@@ -0,0 +1,431 @@
+/**
+ * parser.js
+ */
+
+/* import */
+import * as cssTree from 'css-tree';
+import { getType } from './utility.js';
+
+/* constants */
+import {
+  ATTR_SELECTOR,
+  BIT_01,
+  BIT_02,
+  BIT_04,
+  BIT_08,
+  BIT_16,
+  BIT_32,
+  BIT_FFFF,
+  CLASS_SELECTOR,
+  DUO,
+  HEX,
+  ID_SELECTOR,
+  KEYS_LOGICAL,
+  NTH,
+  PS_CLASS_SELECTOR,
+  PS_ELEMENT_SELECTOR,
+  SELECTOR,
+  SYNTAX_ERR,
+  TYPE_SELECTOR
+} from './constant.js';
+const AST_SORT_ORDER = new Map([
+  [PS_ELEMENT_SELECTOR, BIT_01],
+  [ID_SELECTOR, BIT_02],
+  [CLASS_SELECTOR, BIT_04],
+  [TYPE_SELECTOR, BIT_08],
+  [ATTR_SELECTOR, BIT_16],
+  [PS_CLASS_SELECTOR, BIT_32]
+]);
+const KEYS_PS_CLASS_STATE = new Set([
+  'checked',
+  'closed',
+  'disabled',
+  'empty',
+  'enabled',
+  'in-range',
+  'indeterminate',
+  'invalid',
+  'open',
+  'out-of-range',
+  'placeholder-shown',
+  'read-only',
+  'read-write',
+  'valid'
+]);
+const KEYS_SHADOW_HOST = new Set(['host', 'host-context']);
+const REG_EMPTY_PS_FUNC =
+  /(?<=:(?:dir|has|host(?:-context)?|is|lang|not|nth-(?:last-)?(?:child|of-type)|where))\(\s+\)/g;
+const REG_SHADOW_PS_ELEMENT = /^part|slotted$/;
+const U_FFFD = '\uFFFD';
+
+/**
+ * Unescapes a CSS selector string.
+ * @param {string} selector - The CSS selector to unescape.
+ * @returns {string} The unescaped selector string.
+ */
+export const unescapeSelector = (selector = '') => {
+  if (typeof selector === 'string' && selector.indexOf('\\', 0) >= 0) {
+    const arr = selector.split('\\');
+    const selectorItems = [arr[0]];
+    const l = arr.length;
+    for (let i = 1; i < l; i++) {
+      const item = arr[i];
+      if (item === '' && i === l - 1) {
+        selectorItems.push(U_FFFD);
+      } else {
+        const hexExists = /^([\da-f]{1,6}\s?)/i.exec(item);
+        if (hexExists) {
+          const [, hex] = hexExists;
+          let str;
+          try {
+            const low = parseInt('D800', HEX);
+            const high = parseInt('DFFF', HEX);
+            const deci = parseInt(hex, HEX);
+            if (deci === 0 || (deci >= low && deci <= high)) {
+              str = U_FFFD;
+            } else {
+              str = String.fromCodePoint(deci);
+            }
+          } catch (e) {
+            str = U_FFFD;
+          }
+          let postStr = '';
+          if (item.length > hex.length) {
+            postStr = item.substring(hex.length);
+          }
+          selectorItems.push(`${str}${postStr}`);
+          // whitespace
+        } else if (/^[\n\r\f]/.test(item)) {
+          selectorItems.push(`\\${item}`);
+        } else {
+          selectorItems.push(item);
+        }
+      }
+    }
+    return selectorItems.join('');
+  }
+  return selector;
+};
+
+/**
+ * Preprocesses a selector string according to the specification.
+ * @see https://drafts.csswg.org/css-syntax-3/#input-preprocessing
+ * @param {string} value - The value to preprocess.
+ * @returns {string} The preprocessed selector string.
+ */
+export const preprocess = value => {
+  // Non-string values will be converted to string.
+  if (typeof value !== 'string') {
+    if (value === undefined || value === null) {
+      return getType(value).toLowerCase();
+    } else if (Array.isArray(value)) {
+      return value.join(',');
+    } else if (Object.hasOwn(value, 'toString')) {
+      return value.toString();
+    } else {
+      throw new DOMException(`Invalid selector ${value}`, SYNTAX_ERR);
+    }
+  }
+  let selector = value;
+  let index = 0;
+  while (index >= 0) {
+    // @see https://drafts.csswg.org/selectors/#id-selectors
+    index = selector.indexOf('#', index);
+    if (index < 0) {
+      break;
+    }
+    const preHash = selector.substring(0, index + 1);
+    let postHash = selector.substring(index + 1);
+    const codePoint = postHash.codePointAt(0);
+    if (codePoint > BIT_FFFF) {
+      const str = `\\${codePoint.toString(HEX)} `;
+      if (postHash.length === DUO) {
+        postHash = str;
+      } else {
+        postHash = `${str}${postHash.substring(DUO)}`;
+      }
+    }
+    selector = `${preHash}${postHash}`;
+    index++;
+  }
+  return selector
+    .replace(/\f|\r\n?/g, '\n')
+    .replace(/[\0\uD800-\uDFFF]|\\$/g, U_FFFD)
+    .replace(/\x26/g, ':scope');
+};
+
+/**
+ * Creates an Abstract Syntax Tree (AST) from a CSS selector string.
+ * @param {string} sel - The CSS selector string.
+ * @returns {object} The parsed AST object.
+ */
+export const parseSelector = sel => {
+  const selector = preprocess(sel);
+  // invalid selectors
+  if (/^$|^\s*>|,\s*$/.test(selector)) {
+    throw new DOMException(`Invalid selector ${selector}`, SYNTAX_ERR);
+  }
+  try {
+    const ast = cssTree.parse(selector, {
+      context: 'selectorList',
+      parseCustomProperty: true
+    });
+    return cssTree.toPlainObject(ast);
+  } catch (e) {
+    const { message } = e;
+    if (
+      /^(?:"\]"|Attribute selector [()\s,=~^$*|]+) is expected$/.test(
+        message
+      ) &&
+      !selector.endsWith(']')
+    ) {
+      const index = selector.lastIndexOf('[');
+      const selPart = selector.substring(index);
+      if (selPart.includes('"')) {
+        const quotes = selPart.match(/"/g).length;
+        if (quotes % 2) {
+          return parseSelector(`${selector}"]`);
+        }
+        return parseSelector(`${selector}]`);
+      }
+      return parseSelector(`${selector}]`);
+    } else if (message === '")" is expected') {
+      // workaround for https://github.com/csstree/csstree/issues/283
+      if (REG_EMPTY_PS_FUNC.test(selector)) {
+        return parseSelector(`${selector.replaceAll(REG_EMPTY_PS_FUNC, '()')}`);
+      } else if (!selector.endsWith(')')) {
+        return parseSelector(`${selector})`);
+      } else {
+        throw new DOMException(`Invalid selector ${selector}`, SYNTAX_ERR);
+      }
+    } else {
+      throw new DOMException(`Invalid selector ${selector}`, SYNTAX_ERR);
+    }
+  }
+};
+
+/**
+ * Walks the provided AST to collect selector branches and gather information
+ * about its contents.
+ * @param {object} ast - The AST to traverse.
+ * @returns {{branches: Array<object>, info: object}} An object containing the selector branches and info.
+ */
+export const walkAST = (ast = {}) => {
+  const branches = new Set();
+  const info = {
+    hasForgivenPseudoFunc: false,
+    hasHasPseudoFunc: false,
+    hasLogicalPseudoFunc: false,
+    hasNotPseudoFunc: false,
+    hasNthChildOfSelector: false,
+    hasNestedSelector: false,
+    hasStatePseudoClass: false
+  };
+  const opt = {
+    enter(node) {
+      switch (node.type) {
+        case CLASS_SELECTOR: {
+          if (/^-?\d/.test(node.name)) {
+            throw new DOMException(
+              `Invalid selector .${node.name}`,
+              SYNTAX_ERR
+            );
+          }
+          break;
+        }
+        case ID_SELECTOR: {
+          if (/^-?\d/.test(node.name)) {
+            throw new DOMException(
+              `Invalid selector #${node.name}`,
+              SYNTAX_ERR
+            );
+          }
+          break;
+        }
+        case PS_CLASS_SELECTOR: {
+          if (KEYS_LOGICAL.has(node.name)) {
+            info.hasNestedSelector = true;
+            info.hasLogicalPseudoFunc = true;
+            if (node.name === 'has') {
+              info.hasHasPseudoFunc = true;
+            } else if (node.name === 'not') {
+              info.hasNotPseudoFunc = true;
+            } else {
+              info.hasForgivenPseudoFunc = true;
+            }
+          } else if (KEYS_PS_CLASS_STATE.has(node.name)) {
+            info.hasStatePseudoClass = true;
+          } else if (
+            KEYS_SHADOW_HOST.has(node.name) &&
+            Array.isArray(node.children) &&
+            node.children.length
+          ) {
+            info.hasNestedSelector = true;
+          }
+          break;
+        }
+        case PS_ELEMENT_SELECTOR: {
+          if (REG_SHADOW_PS_ELEMENT.test(node.name)) {
+            info.hasNestedSelector = true;
+          }
+          break;
+        }
+        case NTH: {
+          if (node.selector) {
+            info.hasNestedSelector = true;
+            info.hasNthChildOfSelector = true;
+          }
+          break;
+        }
+        case SELECTOR: {
+          branches.add(node.children);
+          break;
+        }
+        default:
+      }
+    }
+  };
+  cssTree.walk(ast, opt);
+  if (info.hasNestedSelector === true) {
+    cssTree.findAll(ast, (node, item, list) => {
+      if (list) {
+        if (node.type === PS_CLASS_SELECTOR && KEYS_LOGICAL.has(node.name)) {
+          const itemList = list.filter(i => {
+            const { name, type } = i;
+            return type === PS_CLASS_SELECTOR && KEYS_LOGICAL.has(name);
+          });
+          for (const { children } of itemList) {
+            // SelectorList
+            for (const { children: grandChildren } of children) {
+              // Selector
+              for (const { children: greatGrandChildren } of grandChildren) {
+                if (branches.has(greatGrandChildren)) {
+                  branches.delete(greatGrandChildren);
+                }
+              }
+            }
+          }
+        } else if (
+          node.type === PS_CLASS_SELECTOR &&
+          KEYS_SHADOW_HOST.has(node.name) &&
+          Array.isArray(node.children) &&
+          node.children.length
+        ) {
+          const itemList = list.filter(i => {
+            const { children, name, type } = i;
+            const res =
+              type === PS_CLASS_SELECTOR &&
+              KEYS_SHADOW_HOST.has(name) &&
+              Array.isArray(children) &&
+              children.length;
+            return res;
+          });
+          for (const { children } of itemList) {
+            // Selector
+            for (const { children: grandChildren } of children) {
+              if (branches.has(grandChildren)) {
+                branches.delete(grandChildren);
+              }
+            }
+          }
+        } else if (
+          node.type === PS_ELEMENT_SELECTOR &&
+          REG_SHADOW_PS_ELEMENT.test(node.name)
+        ) {
+          const itemList = list.filter(i => {
+            const { name, type } = i;
+            const res =
+              type === PS_ELEMENT_SELECTOR && REG_SHADOW_PS_ELEMENT.test(name);
+            return res;
+          });
+          for (const { children } of itemList) {
+            // Selector
+            for (const { children: grandChildren } of children) {
+              if (branches.has(grandChildren)) {
+                branches.delete(grandChildren);
+              }
+            }
+          }
+        } else if (node.type === NTH && node.selector) {
+          const itemList = list.filter(i => {
+            const { selector, type } = i;
+            const res = type === NTH && selector;
+            return res;
+          });
+          for (const { selector } of itemList) {
+            const { children } = selector;
+            // Selector
+            for (const { children: grandChildren } of children) {
+              if (branches.has(grandChildren)) {
+                branches.delete(grandChildren);
+              }
+            }
+          }
+        }
+      }
+    });
+  }
+  return {
+    info,
+    branches: [...branches]
+  };
+};
+
+/**
+ * Comparison function for sorting AST nodes based on specificity.
+ * @param {object} a - The first AST node.
+ * @param {object} b - The second AST node.
+ * @returns {number} -1, 0 or 1, depending on the sort order.
+ */
+export const compareASTNodes = (a, b) => {
+  const bitA = AST_SORT_ORDER.get(a.type);
+  const bitB = AST_SORT_ORDER.get(b.type);
+  if (bitA === bitB) {
+    return 0;
+  } else if (bitA > bitB) {
+    return 1;
+  } else {
+    return -1;
+  }
+};
+
+/**
+ * Sorts a collection of AST nodes based on CSS specificity rules.
+ * @param {Array<object>} asts - A collection of AST nodes to sort.
+ * @returns {Array<object>} A new array containing the sorted AST nodes.
+ */
+export const sortAST = asts => {
+  const arr = [...asts];
+  if (arr.length > 1) {
+    arr.sort(compareASTNodes);
+  }
+  return arr;
+};
+
+/**
+ * Parses a type selector's name, which may include a namespace prefix.
+ * @param {string} selector - The type selector name (e.g., 'ns|E' or 'E').
+ * @returns {{prefix: string, localName: string}} An object with `prefix` and
+ * `localName` properties.
+ */
+export const parseAstName = selector => {
+  let prefix;
+  let localName;
+  if (selector && typeof selector === 'string') {
+    if (selector.indexOf('|') > -1) {
+      [prefix, localName] = selector.split('|');
+    } else {
+      prefix = '*';
+      localName = selector;
+    }
+  } else {
+    throw new DOMException(`Invalid selector ${selector}`, SYNTAX_ERR);
+  }
+  return {
+    prefix,
+    localName
+  };
+};
+
+/* Re-exported from css-tree. */
+export { find as findAST, generate as generateCSS } from 'css-tree';