@blankeos/velite/dist/index.js

Turns Markdown / MDX, YAML, JSON, or other files into app's data layer with type-safe schema.

import { B as BRAND, D as DIRTY, E as EMPTY_PATH, I as INVALID, N as NEVER, O as OK, P as ParseStatus, Z as ZodType, a as ZodAny, b as ZodArray, c as ZodBigInt, d as ZodBoolean, e as ZodBranded, f as ZodCatch, g as ZodDate, h as ZodDefault, i as ZodDiscriminatedUnion, j as ZodEffects, k as ZodEnum, l as ZodError, m as ZodFirstPartyTypeKind, n as ZodFunction, o as ZodIntersection, p as ZodIssueCode, q as ZodLazy, r as ZodLiteral, s as ZodMap, t as ZodNaN, u as ZodNativeEnum, v as ZodNever, w as ZodNull, x as ZodNullable, y as ZodNumber, z as ZodObject, A as ZodOptional, C as ZodParsedType, F as ZodPipeline, G as ZodPromise, H as ZodReadonly, J as ZodRecord, K as ZodSet, L as ZodString, M as ZodSymbol, Q as ZodTuple, R as ZodUndefined, S as ZodUnion, T as ZodUnknown, U as ZodVoid, V as addIssueToContext, W as anyType, X as arrayType, Y as bigIntType, _ as booleanType, $ as coerce, a0 as custom, a1 as dateType, a2 as datetimeRegex, a3 as errorMap, a4 as discriminatedUnionType, a5 as effectsType, a6 as enumType, a7 as functionType, a8 as getErrorMap, a9 as getParsedType, aa as instanceOfType, ab as intersectionType, ac as isAborted, ad as isAsync, ae as isDirty, af as isValid, ag as late, ah as lazyType, ai as literalType, aj as makeIssue, ak as mapType, al as nanType, am as nativeEnumType, an as neverType, ao as nullType, ap as nullableType, aq as numberType, ar as objectType, as as objectUtil, at as oboolean, au as onumber, av as optionalType, aw as ostring, ax as pipelineType, ay as preprocessType, az as promiseType, aA as quotelessJson, aB as recordType, aC as setType, aD as setErrorMap, aE as strictObjectType, aF as stringType, aG as symbolType, aH as tupleType, aI as undefinedType, aJ as unionType, aK as unknownType, aL as util, aM as voidType, aN as isRelativePath, aO as processAsset, aP as getImageMetadata, aQ as raw$2, aR as svg, aS as find, aT as stringify, aU as stringify$1, aV as zwitch, aW as html$3, aX as htmlVoidElements, aY as convert, aZ as visitParents, a_ as ok, a$ as unicodeWhitespace, b0 as unicodePunctuation, b1 as normalizeIdentifier, b2 as classifyCharacter, b3 as visit, b4 as toString, b5 as EXIT, b6 as asciiAlphanumeric, b7 as asciiAlpha, b8 as markdownLineEndingOrSpace, b9 as asciiControl, ba as blankLine, bb as factorySpace, bc as splice, bd as resolveAll, be as markdownLineEnding, bf as markdownSpace, bg as combineExtensions, bh as fromMarkdown, bi as toHast, bj as getDefaultExportFromCjs, bk as VFile, bl as rehypeCopyLinkedFiles, bm as remarkCopyLinkedFiles, bn as structuredClone } from './velite-oUlu1YbQ.js';
export { bv as VeliteFile, bp as assets, bq as build, br as defineCollection, bu as defineConfig, bs as defineLoader, bt as defineSchema, bo as logger } from './velite-oUlu1YbQ.js';
import { readFile } from 'node:fs/promises';
import { join, relative } from 'node:path';
import 'os';
import 'path';
import 'util';
import 'stream';
import 'events';
import 'fs';
import 'node:crypto';
import 'node:url';
import 'esbuild';

var z = /*#__PURE__*/Object.freeze({
  __proto__: null,
  BRAND: BRAND,
  DIRTY: DIRTY,
  EMPTY_PATH: EMPTY_PATH,
  INVALID: INVALID,
  NEVER: NEVER,
  OK: OK,
  ParseStatus: ParseStatus,
  Schema: ZodType,
  ZodAny: ZodAny,
  ZodArray: ZodArray,
  ZodBigInt: ZodBigInt,
  ZodBoolean: ZodBoolean,
  ZodBranded: ZodBranded,
  ZodCatch: ZodCatch,
  ZodDate: ZodDate,
  ZodDefault: ZodDefault,
  ZodDiscriminatedUnion: ZodDiscriminatedUnion,
  ZodEffects: ZodEffects,
  ZodEnum: ZodEnum,
  ZodError: ZodError,
  ZodFirstPartyTypeKind: ZodFirstPartyTypeKind,
  ZodFunction: ZodFunction,
  ZodIntersection: ZodIntersection,
  ZodIssueCode: ZodIssueCode,
  ZodLazy: ZodLazy,
  ZodLiteral: ZodLiteral,
  ZodMap: ZodMap,
  ZodNaN: ZodNaN,
  ZodNativeEnum: ZodNativeEnum,
  ZodNever: ZodNever,
  ZodNull: ZodNull,
  ZodNullable: ZodNullable,
  ZodNumber: ZodNumber,
  ZodObject: ZodObject,
  ZodOptional: ZodOptional,
  ZodParsedType: ZodParsedType,
  ZodPipeline: ZodPipeline,
  ZodPromise: ZodPromise,
  ZodReadonly: ZodReadonly,
  ZodRecord: ZodRecord,
  ZodSchema: ZodType,
  ZodSet: ZodSet,
  ZodString: ZodString,
  ZodSymbol: ZodSymbol,
  ZodTransformer: ZodEffects,
  ZodTuple: ZodTuple,
  ZodType: ZodType,
  ZodUndefined: ZodUndefined,
  ZodUnion: ZodUnion,
  ZodUnknown: ZodUnknown,
  ZodVoid: ZodVoid,
  addIssueToContext: addIssueToContext,
  any: anyType,
  array: arrayType,
  bigint: bigIntType,
  boolean: booleanType,
  coerce: coerce,
  custom: custom,
  date: dateType,
  datetimeRegex: datetimeRegex,
  defaultErrorMap: errorMap,
  discriminatedUnion: discriminatedUnionType,
  effect: effectsType,
  enum: enumType,
  function: functionType,
  getErrorMap: getErrorMap,
  getParsedType: getParsedType,
  instanceof: instanceOfType,
  intersection: intersectionType,
  isAborted: isAborted,
  isAsync: isAsync,
  isDirty: isDirty,
  isValid: isValid,
  late: late,
  lazy: lazyType,
  literal: literalType,
  makeIssue: makeIssue,
  map: mapType,
  nan: nanType,
  nativeEnum: nativeEnumType,
  never: neverType,
  null: nullType,
  nullable: nullableType,
  number: numberType,
  object: objectType,
  get objectUtil () { return objectUtil; },
  oboolean: oboolean,
  onumber: onumber,
  optional: optionalType,
  ostring: ostring,
  pipeline: pipelineType,
  preprocess: preprocessType,
  promise: promiseType,
  quotelessJson: quotelessJson,
  record: recordType,
  set: setType,
  setErrorMap: setErrorMap,
  strictObject: strictObjectType,
  string: stringType,
  symbol: symbolType,
  transformer: effectsType,
  tuple: tupleType,
  undefined: undefinedType,
  union: unionType,
  unknown: unknownType,
  get util () { return util; },
  void: voidType
});

const excerpt = ({ length = 260 } = {}) => custom((i) => i === void 0 || typeof i === "string").transform(async (value, { meta, addIssue }) => {
  value = value ?? meta.plain;
  if (value == null || value.length === 0) {
    addIssue({ code: "custom", message: "The content is empty" });
    return "";
  }
  return value.slice(0, length);
});

const file = ({ allowNonRelativePath = true } = {}) => stringType().transform(async (value, { meta, addIssue }) => {
  try {
    if (allowNonRelativePath && !isRelativePath(value)) return value;
    const { output } = meta.config;
    return await processAsset(value, meta.path, output.name, output.base);
  } catch (err) {
    const message = err instanceof Error ? err.message : String(err);
    addIssue({ fatal: true, code: "custom", message });
    return null;
  }
});

const image$1 = ({ absoluteRoot } = {}) => stringType().transform(async (value, { meta, addIssue }) => {
  try {
    if (absoluteRoot && /^\//.test(value)) {
      const buffer = await readFile(join(absoluteRoot, value));
      const metadata = await getImageMetadata(buffer);
      if (metadata == null) throw new Error(`Failed to get image metadata: ${value}`);
      return { src: value, ...metadata };
    }
    const { output } = meta.config;
    return await processAsset(value, meta.path, output.name, output.base, true);
  } catch (err) {
    const message = err instanceof Error ? err.message : String(err);
    addIssue({ fatal: true, code: "custom", message });
    return null;
  }
});

const isodate = () => stringType().refine((value) => !isNaN(Date.parse(value)), "Invalid date string").transform((value) => new Date(value).toISOString());

/**
 * @typedef {import('hast').Root} Root
 * @typedef {import('hast-util-raw').Options} RawOptions
 * @typedef {import('vfile').VFile} VFile
 */


/**
 * Parse the tree (and raw nodes) again, keeping positional info okay.
 *
 * @param {Options | null | undefined}  [options]
 *   Configuration (optional).
 * @returns
 *   Transform.
 */
function rehypeRaw(options) {
  /**
   * @param {Root} tree
   *   Tree.
   * @param {VFile} file
   *   File.
   * @returns {Root}
   *   New tree.
   */
  return function (tree, file) {
    // Assume root in -> root out.
    const result = /** @type {Root} */ (raw$2(tree, {...options, file}));
    return result
  }
}

/**
 * @typedef CoreOptions
 * @property {ReadonlyArray<string>} [subset=[]]
 *   Whether to only escape the given subset of characters.
 * @property {boolean} [escapeOnly=false]
 *   Whether to only escape possibly dangerous characters.
 *   Those characters are `"`, `&`, `'`, `<`, `>`, and `` ` ``.
 *
 * @typedef FormatOptions
 * @property {(code: number, next: number, options: CoreWithFormatOptions) => string} format
 *   Format strategy.
 *
 * @typedef {CoreOptions & FormatOptions & import('./util/format-smart.js').FormatSmartOptions} CoreWithFormatOptions
 */

const defaultSubsetRegex = /["&'<>`]/g;
const surrogatePairsRegex = /[\uD800-\uDBFF][\uDC00-\uDFFF]/g;
const controlCharactersRegex =
  // eslint-disable-next-line no-control-regex, unicorn/no-hex-escape
  /[\x01-\t\v\f\x0E-\x1F\x7F\x81\x8D\x8F\x90\x9D\xA0-\uFFFF]/g;
const regexEscapeRegex = /[|\\{}()[\]^$+*?.]/g;

/** @type {WeakMap<ReadonlyArray<string>, RegExp>} */
const subsetToRegexCache = new WeakMap();

/**
 * Encode certain characters in `value`.
 *
 * @param {string} value
 * @param {CoreWithFormatOptions} options
 * @returns {string}
 */
function core(value, options) {
  value = value.replace(
    options.subset
      ? charactersToExpressionCached(options.subset)
      : defaultSubsetRegex,
    basic
  );

  if (options.subset || options.escapeOnly) {
    return value
  }

  return (
    value
      // Surrogate pairs.
      .replace(surrogatePairsRegex, surrogate)
      // BMP control characters (C0 except for LF, CR, SP; DEL; and some more
      // non-ASCII ones).
      .replace(controlCharactersRegex, basic)
  )

  /**
   * @param {string} pair
   * @param {number} index
   * @param {string} all
   */
  function surrogate(pair, index, all) {
    return options.format(
      (pair.charCodeAt(0) - 0xd800) * 0x400 +
        pair.charCodeAt(1) -
        0xdc00 +
        0x10000,
      all.charCodeAt(index + 2),
      options
    )
  }

  /**
   * @param {string} character
   * @param {number} index
   * @param {string} all
   */
  function basic(character, index, all) {
    return options.format(
      character.charCodeAt(0),
      all.charCodeAt(index + 1),
      options
    )
  }
}

/**
 * A wrapper function that caches the result of `charactersToExpression` with a WeakMap.
 * This can improve performance when tooling calls `charactersToExpression` repeatedly
 * with the same subset.
 *
 * @param {ReadonlyArray<string>} subset
 * @returns {RegExp}
 */
function charactersToExpressionCached(subset) {
  let cached = subsetToRegexCache.get(subset);

  if (!cached) {
    cached = charactersToExpression(subset);
    subsetToRegexCache.set(subset, cached);
  }

  return cached
}

/**
 * @param {ReadonlyArray<string>} subset
 * @returns {RegExp}
 */
function charactersToExpression(subset) {
  /** @type {Array<string>} */
  const groups = [];
  let index = -1;

  while (++index < subset.length) {
    groups.push(subset[index].replace(regexEscapeRegex, '\\$&'));
  }

  return new RegExp('(?:' + groups.join('|') + ')', 'g')
}

const hexadecimalRegex = /[\dA-Fa-f]/;

/**
 * Configurable ways to encode characters as hexadecimal references.
 *
 * @param {number} code
 * @param {number} next
 * @param {boolean|undefined} omit
 * @returns {string}
 */
function toHexadecimal(code, next, omit) {
  const value = '&#x' + code.toString(16).toUpperCase();
  return omit && next && !hexadecimalRegex.test(String.fromCharCode(next))
    ? value
    : value + ';'
}

const decimalRegex = /\d/;

/**
 * Configurable ways to encode characters as decimal references.
 *
 * @param {number} code
 * @param {number} next
 * @param {boolean|undefined} omit
 * @returns {string}
 */
function toDecimal(code, next, omit) {
  const value = '&#' + String(code);
  return omit && next && !decimalRegex.test(String.fromCharCode(next))
    ? value
    : value + ';'
}

/**
 * List of legacy HTML named character references that don’t need a trailing semicolon.
 *
 * @type {Array<string>}
 */
const characterEntitiesLegacy = [
  'AElig',
  'AMP',
  'Aacute',
  'Acirc',
  'Agrave',
  'Aring',
  'Atilde',
  'Auml',
  'COPY',
  'Ccedil',
  'ETH',
  'Eacute',
  'Ecirc',
  'Egrave',
  'Euml',
  'GT',
  'Iacute',
  'Icirc',
  'Igrave',
  'Iuml',
  'LT',
  'Ntilde',
  'Oacute',
  'Ocirc',
  'Ograve',
  'Oslash',
  'Otilde',
  'Ouml',
  'QUOT',
  'REG',
  'THORN',
  'Uacute',
  'Ucirc',
  'Ugrave',
  'Uuml',
  'Yacute',
  'aacute',
  'acirc',
  'acute',
  'aelig',
  'agrave',
  'amp',
  'aring',
  'atilde',
  'auml',
  'brvbar',
  'ccedil',
  'cedil',
  'cent',
  'copy',
  'curren',
  'deg',
  'divide',
  'eacute',
  'ecirc',
  'egrave',
  'eth',
  'euml',
  'frac12',
  'frac14',
  'frac34',
  'gt',
  'iacute',
  'icirc',
  'iexcl',
  'igrave',
  'iquest',
  'iuml',
  'laquo',
  'lt',
  'macr',
  'micro',
  'middot',
  'nbsp',
  'not',
  'ntilde',
  'oacute',
  'ocirc',
  'ograve',
  'ordf',
  'ordm',
  'oslash',
  'otilde',
  'ouml',
  'para',
  'plusmn',
  'pound',
  'quot',
  'raquo',
  'reg',
  'sect',
  'shy',
  'sup1',
  'sup2',
  'sup3',
  'szlig',
  'thorn',
  'times',
  'uacute',
  'ucirc',
  'ugrave',
  'uml',
  'uuml',
  'yacute',
  'yen',
  'yuml'
];

/**
 * Map of named character references from HTML 4.
 *
 * @type {Record<string, string>}
 */
const characterEntitiesHtml4 = {
  nbsp: ' ',
  iexcl: '¡',
  cent: '¢',
  pound: '£',
  curren: '¤',
  yen: '¥',
  brvbar: '¦',
  sect: '§',
  uml: '¨',
  copy: '©',
  ordf: 'ª',
  laquo: '«',
  not: '¬',
  shy: '­',
  reg: '®',
  macr: '¯',
  deg: '°',
  plusmn: '±',
  sup2: '²',
  sup3: '³',
  acute: '´',
  micro: 'µ',
  para: '¶',
  middot: '·',
  cedil: '¸',
  sup1: '¹',
  ordm: 'º',
  raquo: '»',
  frac14: '¼',
  frac12: '½',
  frac34: '¾',
  iquest: '¿',
  Agrave: 'À',
  Aacute: 'Á',
  Acirc: 'Â',
  Atilde: 'Ã',
  Auml: 'Ä',
  Aring: 'Å',
  AElig: 'Æ',
  Ccedil: 'Ç',
  Egrave: 'È',
  Eacute: 'É',
  Ecirc: 'Ê',
  Euml: 'Ë',
  Igrave: 'Ì',
  Iacute: 'Í',
  Icirc: 'Î',
  Iuml: 'Ï',
  ETH: 'Ð',
  Ntilde: 'Ñ',
  Ograve: 'Ò',
  Oacute: 'Ó',
  Ocirc: 'Ô',
  Otilde: 'Õ',
  Ouml: 'Ö',
  times: '×',
  Oslash: 'Ø',
  Ugrave: 'Ù',
  Uacute: 'Ú',
  Ucirc: 'Û',
  Uuml: 'Ü',
  Yacute: 'Ý',
  THORN: 'Þ',
  szlig: 'ß',
  agrave: 'à',
  aacute: 'á',
  acirc: 'â',
  atilde: 'ã',
  auml: 'ä',
  aring: 'å',
  aelig: 'æ',
  ccedil: 'ç',
  egrave: 'è',
  eacute: 'é',
  ecirc: 'ê',
  euml: 'ë',
  igrave: 'ì',
  iacute: 'í',
  icirc: 'î',
  iuml: 'ï',
  eth: 'ð',
  ntilde: 'ñ',
  ograve: 'ò',
  oacute: 'ó',
  ocirc: 'ô',
  otilde: 'õ',
  ouml: 'ö',
  divide: '÷',
  oslash: 'ø',
  ugrave: 'ù',
  uacute: 'ú',
  ucirc: 'û',
  uuml: 'ü',
  yacute: 'ý',
  thorn: 'þ',
  yuml: 'ÿ',
  fnof: 'ƒ',
  Alpha: 'Α',
  Beta: 'Β',
  Gamma: 'Γ',
  Delta: 'Δ',
  Epsilon: 'Ε',
  Zeta: 'Ζ',
  Eta: 'Η',
  Theta: 'Θ',
  Iota: 'Ι',
  Kappa: 'Κ',
  Lambda: 'Λ',
  Mu: 'Μ',
  Nu: 'Ν',
  Xi: 'Ξ',
  Omicron: 'Ο',
  Pi: 'Π',
  Rho: 'Ρ',
  Sigma: 'Σ',
  Tau: 'Τ',
  Upsilon: 'Υ',
  Phi: 'Φ',
  Chi: 'Χ',
  Psi: 'Ψ',
  Omega: 'Ω',
  alpha: 'α',
  beta: 'β',
  gamma: 'γ',
  delta: 'δ',
  epsilon: 'ε',
  zeta: 'ζ',
  eta: 'η',
  theta: 'θ',
  iota: 'ι',
  kappa: 'κ',
  lambda: 'λ',
  mu: 'μ',
  nu: 'ν',
  xi: 'ξ',
  omicron: 'ο',
  pi: 'π',
  rho: 'ρ',
  sigmaf: 'ς',
  sigma: 'σ',
  tau: 'τ',
  upsilon: 'υ',
  phi: 'φ',
  chi: 'χ',
  psi: 'ψ',
  omega: 'ω',
  thetasym: 'ϑ',
  upsih: 'ϒ',
  piv: 'ϖ',
  bull: '•',
  hellip: '…',
  prime: '′',
  Prime: '″',
  oline: '‾',
  frasl: '⁄',
  weierp: '℘',
  image: 'ℑ',
  real: 'ℜ',
  trade: '™',
  alefsym: 'ℵ',
  larr: '←',
  uarr: '↑',
  rarr: '→',
  darr: '↓',
  harr: '↔',
  crarr: '↵',
  lArr: '⇐',
  uArr: '⇑',
  rArr: '⇒',
  dArr: '⇓',
  hArr: '⇔',
  forall: '∀',
  part: '∂',
  exist: '∃',
  empty: '∅',
  nabla: '∇',
  isin: '∈',
  notin: '∉',
  ni: '∋',
  prod: '∏',
  sum: '∑',
  minus: '−',
  lowast: '∗',
  radic: '√',
  prop: '∝',
  infin: '∞',
  ang: '∠',
  and: '∧',
  or: '∨',
  cap: '∩',
  cup: '∪',
  int: '∫',
  there4: '∴',
  sim: '∼',
  cong: '≅',
  asymp: '≈',
  ne: '≠',
  equiv: '≡',
  le: '≤',
  ge: '≥',
  sub: '⊂',
  sup: '⊃',
  nsub: '⊄',
  sube: '⊆',
  supe: '⊇',
  oplus: '⊕',
  otimes: '⊗',
  perp: '⊥',
  sdot: '⋅',
  lceil: '⌈',
  rceil: '⌉',
  lfloor: '⌊',
  rfloor: '⌋',
  lang: '〈',
  rang: '〉',
  loz: '◊',
  spades: '♠',
  clubs: '♣',
  hearts: '♥',
  diams: '♦',
  quot: '"',
  amp: '&',
  lt: '<',
  gt: '>',
  OElig: 'Œ',
  oelig: 'œ',
  Scaron: 'Š',
  scaron: 'š',
  Yuml: 'Ÿ',
  circ: 'ˆ',
  tilde: '˜',
  ensp: ' ',
  emsp: ' ',
  thinsp: ' ',
  zwnj: '‌',
  zwj: '‍',
  lrm: '‎',
  rlm: '‏',
  ndash: '–',
  mdash: '—',
  lsquo: '‘',
  rsquo: '’',
  sbquo: '‚',
  ldquo: '“',
  rdquo: '”',
  bdquo: '„',
  dagger: '†',
  Dagger: '‡',
  permil: '‰',
  lsaquo: '‹',
  rsaquo: '›',
  euro: '€'
};

/**
 * List of legacy (that don’t need a trailing `;`) named references which could,
 * depending on what follows them, turn into a different meaning
 *
 * @type {Array<string>}
 */
const dangerous = [
  'cent',
  'copy',
  'divide',
  'gt',
  'lt',
  'not',
  'para',
  'times'
];

const own$3 = {}.hasOwnProperty;

/**
 * `characterEntitiesHtml4` but inverted.
 *
 * @type {Record<string, string>}
 */
const characters = {};

/** @type {string} */
let key;

for (key in characterEntitiesHtml4) {
  if (own$3.call(characterEntitiesHtml4, key)) {
    characters[characterEntitiesHtml4[key]] = key;
  }
}

const notAlphanumericRegex = /[^\dA-Za-z]/;

/**
 * Configurable ways to encode characters as named references.
 *
 * @param {number} code
 * @param {number} next
 * @param {boolean|undefined} omit
 * @param {boolean|undefined} attribute
 * @returns {string}
 */
function toNamed(code, next, omit, attribute) {
  const character = String.fromCharCode(code);

  if (own$3.call(characters, character)) {
    const name = characters[character];
    const value = '&' + name;

    if (
      omit &&
      characterEntitiesLegacy.includes(name) &&
      !dangerous.includes(name) &&
      (!attribute ||
        (next &&
          next !== 61 /* `=` */ &&
          notAlphanumericRegex.test(String.fromCharCode(next))))
    ) {
      return value
    }

    return value + ';'
  }

  return ''
}

/**
 * @typedef FormatSmartOptions
 * @property {boolean} [useNamedReferences=false]
 *   Prefer named character references (`&amp;`) where possible.
 * @property {boolean} [useShortestReferences=false]
 *   Prefer the shortest possible reference, if that results in less bytes.
 *   **Note**: `useNamedReferences` can be omitted when using `useShortestReferences`.
 * @property {boolean} [omitOptionalSemicolons=false]
 *   Whether to omit semicolons when possible.
 *   **Note**: This creates what HTML calls “parse errors” but is otherwise still valid HTML — don’t use this except when building a minifier.
 *   Omitting semicolons is possible for certain named and numeric references in some cases.
 * @property {boolean} [attribute=false]
 *   Create character references which don’t fail in attributes.
 *   **Note**: `attribute` only applies when operating dangerously with
 *   `omitOptionalSemicolons: true`.
 */


/**
 * Configurable ways to encode a character yielding pretty or small results.
 *
 * @param {number} code
 * @param {number} next
 * @param {FormatSmartOptions} options
 * @returns {string}
 */
function formatSmart(code, next, options) {
  let numeric = toHexadecimal(code, next, options.omitOptionalSemicolons);
  /** @type {string|undefined} */
  let named;

  if (options.useNamedReferences || options.useShortestReferences) {
    named = toNamed(
      code,
      next,
      options.omitOptionalSemicolons,
      options.attribute
    );
  }

  // Use the shortest numeric reference when requested.
  // A simple algorithm would use decimal for all code points under 100, as
  // those are shorter than hexadecimal:
  //
  // * `&#99;` vs `&#x63;` (decimal shorter)
  // * `&#100;` vs `&#x64;` (equal)
  //
  // However, because we take `next` into consideration when `omit` is used,
  // And it would be possible that decimals are shorter on bigger values as
  // well if `next` is hexadecimal but not decimal, we instead compare both.
  if (
    (options.useShortestReferences || !named) &&
    options.useShortestReferences
  ) {
    const decimal = toDecimal(code, next, options.omitOptionalSemicolons);

    if (decimal.length < numeric.length) {
      numeric = decimal;
    }
  }

  return named &&
    (!options.useShortestReferences || named.length < numeric.length)
    ? named
    : numeric
}

/**
 * @typedef {import('./core.js').CoreOptions & import('./util/format-smart.js').FormatSmartOptions} Options
 * @typedef {import('./core.js').CoreOptions} LightOptions
 */


/**
 * Encode special characters in `value`.
 *
 * @param {string} value
 *   Value to encode.
 * @param {Options} [options]
 *   Configuration.
 * @returns {string}
 *   Encoded value.
 */
function stringifyEntities(value, options) {
  return core(value, Object.assign({format: formatSmart}, options))
}

/**
 * @import {Comment, Parents} from 'hast'
 * @import {State} from '../index.js'
 */


const htmlCommentRegex = /^>|^->|<!--|-->|--!>|<!-$/g;

// Declare arrays as variables so it can be cached by `stringifyEntities`
const bogusCommentEntitySubset = ['>'];
const commentEntitySubset = ['<', '>'];

/**
 * Serialize a comment.
 *
 * @param {Comment} node
 *   Node to handle.
 * @param {number | undefined} _1
 *   Index of `node` in `parent.
 * @param {Parents | undefined} _2
 *   Parent of `node`.
 * @param {State} state
 *   Info passed around about the current state.
 * @returns {string}
 *   Serialized node.
 */
function comment(node, _1, _2, state) {
  // See: <https://html.spec.whatwg.org/multipage/syntax.html#comments>
  return state.settings.bogusComments
    ? '<?' +
        stringifyEntities(
          node.value,
          Object.assign({}, state.settings.characterReferences, {
            subset: bogusCommentEntitySubset
          })
        ) +
        '>'
    : '<!--' + node.value.replace(htmlCommentRegex, encode) + '-->'

  /**
   * @param {string} $0
   */
  function encode($0) {
    return stringifyEntities(
      $0,
      Object.assign({}, state.settings.characterReferences, {
        subset: commentEntitySubset
      })
    )
  }
}

/**
 * @import {Doctype, Parents} from 'hast'
 * @import {State} from '../index.js'
 */

/**
 * Serialize a doctype.
 *
 * @param {Doctype} _1
 *   Node to handle.
 * @param {number | undefined} _2
 *   Index of `node` in `parent.
 * @param {Parents | undefined} _3
 *   Parent of `node`.
 * @param {State} state
 *   Info passed around about the current state.
 * @returns {string}
 *   Serialized node.
 */
function doctype(_1, _2, _3, state) {
  return (
    '<!' +
    (state.settings.upperDoctype ? 'DOCTYPE' : 'doctype') +
    (state.settings.tightDoctype ? '' : ' ') +
    'html>'
  )
}

/**
 * Count how often a character (or substring) is used in a string.
 *
 * @param {string} value
 *   Value to search in.
 * @param {string} character
 *   Character (or substring) to look for.
 * @return {number}
 *   Number of times `character` occurred in `value`.
 */
function ccount(value, character) {
  const source = String(value);

  if (typeof character !== 'string') {
    throw new TypeError('Expected character')
  }

  let count = 0;
  let index = source.indexOf(character);

  while (index !== -1) {
    count++;
    index = source.indexOf(character, index + character.length);
  }

  return count
}

/**
 * @typedef {import('hast').Nodes} Nodes
 */

// HTML whitespace expression.
// See <https://infra.spec.whatwg.org/#ascii-whitespace>.
const re = /[ \t\n\f\r]/g;

/**
 * Check if the given value is *inter-element whitespace*.
 *
 * @param {Nodes | string} thing
 *   Thing to check (`Node` or `string`).
 * @returns {boolean}
 *   Whether the `value` is inter-element whitespace (`boolean`): consisting of
 *   zero or more of space, tab (`\t`), line feed (`\n`), carriage return
 *   (`\r`), or form feed (`\f`); if a node is passed it must be a `Text` node,
 *   whose `value` field is checked.
 */
function whitespace(thing) {
  return typeof thing === 'object'
    ? thing.type === 'text'
      ? empty(thing.value)
      : false
    : empty(thing)
}

/**
 * @param {string} value
 * @returns {boolean}
 */
function empty(value) {
  return value.replace(re, '') === ''
}

/**
 * @import {Parents, RootContent} from 'hast'
 */


const siblingAfter = siblings(1);
const siblingBefore = siblings(-1);

/** @type {Array<RootContent>} */
const emptyChildren$1 = [];

/**
 * Factory to check siblings in a direction.
 *
 * @param {number} increment
 */
function siblings(increment) {
  return sibling

  /**
   * Find applicable siblings in a direction.
   *
   * @template {Parents} Parent
   *   Parent type.
   * @param {Parent | undefined} parent
   *   Parent.
   * @param {number | undefined} index
   *   Index of child in `parent`.
   * @param {boolean | undefined} [includeWhitespace=false]
   *   Whether to include whitespace (default: `false`).
   * @returns {Parent extends {children: Array<infer Child>} ? Child | undefined : never}
   *   Child of parent.
   */
  function sibling(parent, index, includeWhitespace) {
    const siblings = parent ? parent.children : emptyChildren$1;
    let offset = (index || 0) + increment;
    let next = siblings[offset];

    if (!includeWhitespace) {
      while (next && whitespace(next)) {
        offset += increment;
        next = siblings[offset];
      }
    }

    // @ts-expect-error: it’s a correct child.
    return next
  }
}

/**
 * @import {Element, Parents} from 'hast'
 */

/**
 * @callback OmitHandle
 *   Check if a tag can be omitted.
 * @param {Element} element
 *   Element to check.
 * @param {number | undefined} index
 *   Index of element in parent.
 * @param {Parents | undefined} parent
 *   Parent of element.
 * @returns {boolean}
 *   Whether to omit a tag.
 *
 */

const own$2 = {}.hasOwnProperty;

/**
 * Factory to check if a given node can have a tag omitted.
 *
 * @param {Record<string, OmitHandle>} handlers
 *   Omission handlers, where each key is a tag name, and each value is the
 *   corresponding handler.
 * @returns {OmitHandle}
 *   Whether to omit a tag of an element.
 */
function omission(handlers) {
  return omit

  /**
   * Check if a given node can have a tag omitted.
   *
   * @type {OmitHandle}
   */
  function omit(node, index, parent) {
    return (
      own$2.call(handlers, node.tagName) &&
      handlers[node.tagName](node, index, parent)
    )
  }
}

/**
 * @import {Element, Parents} from 'hast'
 */


const closing = omission({
  body: body$1,
  caption: headOrColgroupOrCaption,
  colgroup: headOrColgroupOrCaption,
  dd,
  dt,
  head: headOrColgroupOrCaption,
  html: html$2,
  li,
  optgroup,
  option,
  p,
  rp: rubyElement,
  rt: rubyElement,
  tbody: tbody$1,
  td: cells,
  tfoot,
  th: cells,
  thead,
  tr
});

/**
 * Macro for `</head>`, `</colgroup>`, and `</caption>`.
 *
 * @param {Element} _
 *   Element.
 * @param {number | undefined} index
 *   Index of element in parent.
 * @param {Parents | undefined} parent
 *   Parent of element.
 * @returns {boolean}
 *   Whether the closing tag can be omitted.
 */
function headOrColgroupOrCaption(_, index, parent) {
  const next = siblingAfter(parent, index, true);
  return (
    !next ||
    (next.type !== 'comment' &&
      !(next.type === 'text' && whitespace(next.value.charAt(0))))
  )
}

/**
 * Whether to omit `</html>`.
 *
 * @param {Element} _
 *   Element.
 * @param {number | undefined} index
 *   Index of element in parent.
 * @param {Parents | undefined} parent
 *   Parent of element.
 * @returns {boolean}
 *   Whether the closing tag can be omitted.
 */
function html$2(_, index, parent) {
  const next = siblingAfter(parent, index);
  return !next || next.type !== 'comment'
}

/**
 * Whether to omit `</body>`.
 *
 * @param {Element} _
 *   Element.
 * @param {number | undefined} index
 *   Index of element in parent.
 * @param {Parents | undefined} parent
 *   Parent of element.
 * @returns {boolean}
 *   Whether the closing tag can be omitted.
 */
function body$1(_, index, parent) {
  const next = siblingAfter(parent, index);
  return !next || next.type !== 'comment'
}

/**
 * Whether to omit `</p>`.
 *
 * @param {Element} _
 *   Element.
 * @param {number | undefined} index
 *   Index of element in parent.
 * @param {Parents | undefined} parent
 *   Parent of element.
 * @returns {boolean}
 *   Whether the closing tag can be omitted.
 */
function p(_, index, parent) {
  const next = siblingAfter(parent, index);
  return next
    ? next.type === 'element' &&
        (next.tagName === 'address' ||
          next.tagName === 'article' ||
          next.tagName === 'aside' ||
          next.tagName === 'blockquote' ||
          next.tagName === 'details' ||
          next.tagName === 'div' ||
          next.tagName === 'dl' ||
          next.tagName === 'fieldset' ||
          next.tagName === 'figcaption' ||
          next.tagName === 'figure' ||
          next.tagName === 'footer' ||
          next.tagName === 'form' ||
          next.tagName === 'h1' ||
          next.tagName === 'h2' ||
          next.tagName === 'h3' ||
          next.tagName === 'h4' ||
          next.tagName === 'h5' ||
          next.tagName === 'h6' ||
          next.tagName === 'header' ||
          next.tagName === 'hgroup' ||
          next.tagName === 'hr' ||
          next.tagName === 'main' ||
          next.tagName === 'menu' ||
          next.tagName === 'nav' ||
          next.tagName === 'ol' ||
          next.tagName === 'p' ||
          next.tagName === 'pre' ||
          next.tagName === 'section' ||
          next.tagName === 'table' ||
          next.tagName === 'ul')
    : !parent ||
        // Confusing parent.
        !(
          parent.type === 'element' &&
          (parent.tagName === 'a' ||
            parent.tagName === 'audio' ||
            parent.tagName === 'del' ||
            parent.tagName === 'ins' ||
            parent.tagName === 'map' ||
            parent.tagName === 'noscript' ||
            parent.tagName === 'video')
        )
}

/**
 * Whether to omit `</li>`.
 *
 * @param {Element} _
 *   Element.
 * @param {number | undefined} index
 *   Index of element in parent.
 * @param {Parents | undefined} parent
 *   Parent of element.
 * @returns {boolean}
 *   Whether the closing tag can be omitted.
 */
function li(_, index, parent) {
  const next = siblingAfter(parent, index);
  return !next || (next.type === 'element' && next.tagName === 'li')
}

/**
 * Whether to omit `</dt>`.
 *
 * @param {Element} _
 *   Element.
 * @param {number | undefined} index
 *   Index of element in parent.
 * @param {Parents | undefined} parent
 *   Parent of element.
 * @returns {boolean}
 *   Whether the closing tag can be omitted.
 */
function dt(_, index, parent) {
  const next = siblingAfter(parent, index);
  return Boolean(
    next &&
      next.type === 'element' &&
      (next.tagName === 'dt' || next.tagName === 'dd')
  )
}

/**
 * Whether to omit `</dd>`.
 *
 * @param {Element} _
 *   Element.
 * @param {number | undefined} index
 *   Index of element in parent.
 * @param {Parents | undefined} parent
 *   Parent of element.
 * @returns {boolean}
 *   Whether the closing tag can be omitted.
 */
function dd(_, index, parent) {
  const next = siblingAfter(parent, index);
  return (
    !next ||
    (next.type === 'element' &&
      (next.tagName === 'dt' || next.tagName === 'dd'))
  )
}

/**
 * Whether to omit `</rt>` or `</rp>`.
 *
 * @param {Element} _
 *   Element.
 * @param {number | undefined} index
 *   Index of element in parent.
 * @param {Parents | undefined} parent
 *   Parent of element.
 * @returns {boolean}
 *   Whether the closing tag can be omitted.
 */
function rubyElement(_, index, parent) {
  const next = siblingAfter(parent, index);
  return (
    !next ||
    (next.type === 'element' &&
      (next.tagName === 'rp' || next.tagName === 'rt'))
  )
}

/**
 * Whether to omit `</optgroup>`.
 *
 * @param {Element} _
 *   Element.
 * @param {number | undefined} index
 *   Index of element in parent.
 * @param {Parents | undefined} parent
 *   Parent of element.
 * @returns {boolean}
 *   Whether the closing tag can be omitted.
 */
function optgroup(_, index, parent) {
  const next = siblingAfter(parent, index);
  return !next || (next.type === 'element' && next.tagName === 'optgroup')
}

/**
 * Whether to omit `</option>`.
 *
 * @param {Element} _
 *   Element.
 * @param {number | undefined} index
 *   Index of element in parent.
 * @param {Parents | undefined} parent
 *   Parent of element.
 * @returns {boolean}
 *   Whether the closing tag can be omitted.
 */
function option(_, index, parent) {
  const next = siblingAfter(parent, index);
  return (
    !next ||
    (next.type === 'element' &&
      (next.tagName === 'option' || next.tagName === 'optgroup'))
  )
}

/**
 * Whether to omit `</thead>`.
 *
 * @param {Element} _
 *   Element.
 * @param {number | undefined} index
 *   Index of element in parent.
 * @param {Parents | undefined} parent
 *   Parent of element.
 * @returns {boolean}
 *   Whether the closing tag can be omitted.
 */
function thead(_, index, parent) {
  const next = siblingAfter(parent, index);
  return Boolean(
    next &&
      next.type === 'element' &&
      (next.tagName === 'tbody' || next.tagName === 'tfoot')
  )
}

/**
 * Whether to omit `</tbody>`.
 *
 * @param {Element} _
 *   Element.
 * @param {number | undefined} index
 *   Index of element in parent.
 * @param {Parents | undefined} parent
 *   Parent of element.
 * @returns {boolean}
 *   Whether the closing tag can be omitted.
 */
function tbody$1(_, index, parent) {
  const next = siblingAfter(parent, index);
  return (
    !next ||
    (next.type === 'element' &&
      (next.tagName === 'tbody' || next.tagName === 'tfoot'))
  )
}

/**
 * Whether to omit `</tfoot>`.
 *
 * @param {Element} _
 *   Element.
 * @param {number | undefined} index
 *   Index of element in parent.
 * @param {Parents | undefined} parent
 *   Parent of element.
 * @returns {boolean}
 *   Whether the closing tag can be omitted.
 */
function tfoot(_, index, parent) {
  return !siblingAfter(parent, index)
}

/**
 * Whether to omit `</tr>`.
 *
 * @param {Element} _
 *   Element.
 * @param {number | undefined} index
 *   Index of element in parent.
 * @param {Parents | undefined} parent
 *   Parent of element.
 * @returns {boolean}
 *   Whether the closing tag can be omitted.
 */
function tr(_, index, parent) {
  const next = siblingAfter(parent, index);
  return !next || (next.type === 'element' && next.tagName === 'tr')
}

/**
 * Whether to omit `</td>` or `</th>`.
 *
 * @param {Element} _
 *   Element.
 * @param {number | undefined} index
 *   Index of element in parent.
 * @param {Parents | undefined} parent
 *   Parent of element.
 * @returns {boolean}
 *   Whether the closing tag can be omitted.
 */
function cells(_, index, parent) {
  const next = siblingAfter(parent, index);
  return (
    !next ||
    (next.type === 'element' &&
      (next.tagName === 'td' || next.tagName === 'th'))
  )
}

/**
 * @import {Element, Parents} from 'hast'
 */


const opening = omission({
  body,
  colgroup,
  head,
  html: html$1,
  tbody
});

/**
 * Whether to omit `<html>`.
 *
 * @param {Element} node
 *   Element.
 * @returns {boolean}
 *   Whether the opening tag can be omitted.
 */
function html$1(node) {
  const head = siblingAfter(node, -1);
  return !head || head.type !== 'comment'
}

/**
 * Whether to omit `<head>`.
 *
 * @param {Element} node
 *   Element.
 * @returns {boolean}
 *   Whether the opening tag can be omitted.
 */
function head(node) {
  /** @type {Set<string>} */
  const seen = new Set();

  // Whether `srcdoc` or not,
  // make sure the content model at least doesn’t have too many `base`s/`title`s.
  for (const child of node.children) {
    if (
      child.type === 'element' &&
      (child.tagName === 'base' || child.tagName === 'title')
    ) {
      if (seen.has(child.tagName)) return false
      seen.add(child.tagName);
    }
  }

  // “May be omitted if the element is empty,
  // or if the first thing inside the head element is an element.”
  const child = node.children[0];
  return !child || child.type === 'element'
}

/**
 * Whether to omit `<body>`.
 *
 * @param {Element} node
 *   Element.
 * @returns {boolean}
 *   Whether the opening tag can be omitted.
 */
function body(node) {
  const head = siblingAfter(node, -1, true);

  return (
    !head ||
    (head.type !== 'comment' &&
      !(head.type === 'text' && whitespace(head.value.charAt(0))) &&
      !(
        head.type === 'element' &&
        (head.tagName === 'meta' ||
          head.tagName === 'link' ||
          head.tagName === 'script' ||
          head.tagName === 'style' ||
          head.tagName === 'template')
      ))
  )
}

/**
 * Whether to omit `<colgroup>`.
 * The spec describes some logic for the opening tag, but it’s easier to
 * implement in the closing tag, to the same effect, so we handle it there
 * instead.
 *
 * @param {Element} node
 *   Element.
 * @param {number | undefined} index
 *   Index of element in parent.
 * @param {Parents | undefined} parent
 *   Parent of element.
 * @returns {boolean}
 *   Whether the opening tag can be omitted.
 */
function colgroup(node, index, parent) {
  const previous = siblingBefore(parent, index);
  const head = siblingAfter(node, -1, true);

  // Previous colgroup was already omitted.
  if (
    parent &&
    previous &&
    previous.type === 'element' &&
    previous.tagName === 'colgroup' &&
    closing(previous, parent.children.indexOf(previous), parent)
  ) {
    return false
  }

  return Boolean(head && head.type === 'element' && head.tagName === 'col')
}

/**
 * Whether to omit `<tbody>`.
 *
 * @param {Element} node
 *   Element.
 * @param {number | undefined} index
 *   Index of element in parent.
 * @param {Parents | undefined} parent
 *   Parent of element.
 * @returns {boolean}
 *   Whether the opening tag can be omitted.
 */
function tbody(node, index, parent) {
  const previous = siblingBefore(parent, index);
  const head = siblingAfter(node, -1);

  // Previous table section was already omitted.
  if (
    parent &&
    previous &&
    previous.type === 'element' &&
    (previous.tagName === 'thead' || previous.tagName === 'tbody') &&
    closing(previous, parent.children.indexOf(previous), parent)
  ) {
    return false
  }

  return Boolean(head && head.type === 'element' && head.tagName === 'tr')
}

/**
 * @import {Element, Parents, Properties} from 'hast'
 * @import {State} from '../index.js'
 */


/**
 * Maps of subsets.
 *
 * Each value is a matrix of tuples.
 * The value at `0` causes parse errors, the value at `1` is valid.
 * Of both, the value at `0` is unsafe, and the value at `1` is safe.
 *
 * @type {Record<'double' | 'name' | 'single' | 'unquoted', Array<[Array<string>, Array<string>]>>}
 */
const constants = {
  // See: <https://html.spec.whatwg.org/#attribute-name-state>.
  name: [
    ['\t\n\f\r &/=>'.split(''), '\t\n\f\r "&\'/=>`'.split('')],
    ['\0\t\n\f\r "&\'/<=>'.split(''), '\0\t\n\f\r "&\'/<=>`'.split('')]
  ],
  // See: <https://html.spec.whatwg.org/#attribute-value-(unquoted)-state>.
  unquoted: [
    ['\t\n\f\r &>'.split(''), '\0\t\n\f\r "&\'<=>`'.split('')],
    ['\0\t\n\f\r "&\'<=>`'.split(''), '\0\t\n\f\r "&\'<=>`'.split('')]
  ],
  // See: <https://html.spec.whatwg.org/#attribute-value-(single-quoted)-state>.
  single: [
    ["&'".split(''), '"&\'`'.split('')],
    ["\0&'".split(''), '\0"&\'`'.split('')]
  ],
  // See: <https://html.spec.whatwg.org/#attribute-value-(double-quoted)-state>.
  double: [
    ['"&'.split(''), '"&\'`'.split('')],
    ['\0"&'.split(''), '\0"&\'`'.split('')]
  ]
};

/**
 * Serialize an element node.
 *
 * @param {Element} node
 *   Node to handle.
 * @param {number | undefined} index
 *   Index of `node` in `parent.
 * @param {Parents | undefined} parent
 *   Parent of `node`.
 * @param {State} state
 *   Info passed around about the current state.
 * @returns {string}
 *   Serialized node.
 */
function element(node, index, parent, state) {
  const schema = state.schema;
  const omit = schema.space === 'svg' ? false : state.settings.omitOptionalTags;
  let selfClosing =
    schema.space === 'svg'
      ? state.settings.closeEmptyElements
      : state.settings.voids.includes(node.tagName.toLowerCase());
  /** @type {Array<string>} */
  const parts = [];
  /** @type {string} */
  let last;

  if (schema.space === 'html' && node.tagName === 'svg') {
    state.schema = svg;
  }

  const attributes = serializeAttributes(state, node.properties);

  const content = state.all(
    schema.space === 'html' && node.tagName === 'template' ? node.content : node
  );

  state.schema = schema;

  // If the node is categorised as void, but it has children, remove the
  // categorisation.
  // This enables for example `menuitem`s, which are void in W3C HTML but not
  // void in WHATWG HTML, to be stringified properly.
  // Note: `menuitem` has since been removed from the HTML spec, and so is no
  // longer void.
  if (content) selfClosing = false;

  if (attributes || !omit || !opening(node, index, parent)) {
    parts.push('<', node.tagName, attributes ? ' ' + attributes : '');

    if (
      selfClosing &&
      (schema.space === 'svg' || state.settings.closeSelfClosing)
    ) {
      last = attributes.charAt(attributes.length - 1);
      if (
        !state.settings.tightSelfClosing ||
        last === '/' ||
        (last && last !== '"' && last !== "'")
      ) {
        parts.push(' ');
      }

      parts.push('/');
    }

    parts.push('>');
  }

  parts.push(content);

  if (!selfClosing && (!omit || !closing(node, index, parent))) {
    parts.push('</' + node.tagName + '>');
  }

  return parts.join('')
}

/**
 * @param {State} state
 * @param {Properties | null | undefined} properties
 * @returns {string}
 */
function serializeAttributes(state, properties) {
  /** @type {Array<string>} */
  const values = [];
  let index = -1;
  /** @type {string} */
  let key;

  if (properties) {
    for (key in properties) {
      if (properties[key] !== null && properties[key] !== undefined) {
        const value = serializeAttribute(state, key, properties[key]);
        if (value) values.push(value);
      }
    }
  }

  while (++index < values.length) {
    const last = state.settings.tightAttributes
      ? values[index].charAt(values[index].length - 1)
      : undefined;

    // In tight mode, don’t add a space after quoted attributes.
    if (index !== values.length - 1 && last !== '"' && last !== "'") {
      values[index] += ' ';
    }
  }

  return values.join('')
}

/**
 * @param {State} state
 * @param {string} key
 * @param {Properties[keyof Properties]} value
 * @returns {string}
 */
function serializeAttribute(state, key, value) {
  const info = find(state.schema, key);
  const x =
    state.settings.allowParseErrors && state.schema.space === 'html' ? 0 : 1;
  const y = state.settings.allowDangerousCharacters ? 0 : 1;
  let quote = state.quote;
  /** @type {string | undefined} */
  let result;

  if (info.overloadedBoolean && (value === info.attribute || value === '')) {
    value = true;
  } else if (
    (info.boolean || info.overloadedBoolean) &&
    (typeof value !== 'string' || value === info.attribute || value === '')
  ) {
    value = Boolean(value);
  }

  if (
    value === null ||
    value === undefined ||
    value === false ||
    (typeof value === 'number' && Number.isNaN(value))
  ) {
    return ''
  }

  const name = stringifyEntities(
    info.attribute,
    Object.assign({}, state.settings.characterReferences, {
      // Always encode without parse errors in non-HTML.
      subset: constants.name[x][y]
    })
  );

  // No value.
  // There is currently only one boolean property in SVG: `[download]` on
  // `<a>`.
  // This property does not seem to work in browsers (Firefox, Safari, Chrome),
  // so I can’t test if dropping the value works.
  // But I assume that it should:
  //
  // ```html
  // <!doctype html>
  // <svg viewBox="0 0 100 100">
  //   <a href=https://example.com download>
  //     <circle cx=50 cy=40 r=35 />
  //   </a>
  // </svg>
  // ```
  //
  // See: <https://github.com/wooorm/property-information/blob/main/lib/svg.js>
  if (value === true) return name

  // `spaces` doesn’t accept a second argument, but it’s given here just to
  // keep the code cleaner.
  value = Array.isArray(value)
    ? (info.commaSeparated ? stringify : stringify$1)(value, {
        padLeft: !state.settings.tightCommaSeparatedLists
      })
    : String(value);

  if (state.settings.collapseEmptyAttributes && !value) return name

  // Check unquoted value.
  if (state.settings.preferUnquoted) {
    result = stringifyEntities(
      value,
      Object.assign({}, state.settings.characterReferences, {
        attribute: true,
        subset: constants.unquoted[x][y]
      })
    );
  }

  // If we don’t want unquoted, or if `value` contains character references when
  // unquoted…
  if (result !== value) {
    // If the alternative is less common than `quote`, switch.
    if (
      state.settings.quoteSmart &&
      ccount(value, quote) > ccount(value, state.alternative)
    ) {
      quote = state.alternative;
    }

    result =
      quote +
      stringifyEntities(
        value,
        Object.assign({}, state.settings.characterReferences, {
          // Always encode without parse errors in non-HTML.
          subset: (quote === "'" ? constants.single : constants.double)[x][y],
          attribute: true
        })
      ) +
      quote;
  }

  // Don’t add a `=` for unquoted empties.
  return name + (result ? '=' + result : result)
}

/**
 * @import {Parents, Text} from 'hast'
 * @import {Raw} from 'mdast-util-to-hast'
 * @import {State} from '../index.js'
 */


// Declare array as variable so it can be cached by `stringifyEntities`
const textEntitySubset = ['<', '&'];

/**
 * Serialize a text node.
 *
 * @param {Raw | Text} node
 *   Node to handle.
 * @param {number | undefined} _
 *   Index of `node` in `parent.
 * @param {Parents | undefined} parent
 *   Parent of `node`.
 * @param {State} state
 *   Info passed around about the current state.
 * @returns {string}
 *   Serialized node.
 */
function text$2(node, _, parent, state) {
  // Check if content of `node` should be escaped.
  return parent &&
    parent.type === 'element' &&
    (parent.tagName === 'script' || parent.tagName === 'style')
    ? node.value
    : stringifyEntities(
        node.value,
        Object.assign({}, state.settings.characterReferences, {
          subset: textEntitySubset
        })
      )
}

/**
 * @import {Parents} from 'hast'
 * @import {Raw} from 'mdast-util-to-hast'
 * @import {State} from '../index.js'
 */


/**
 * Serialize a raw node.
 *
 * @param {Raw} node
 *   Node to handle.
 * @param {number | undefined} index
 *   Index of `node` in `parent.
 * @param {Parents | undefined} parent
 *   Parent of `node`.
 * @param {State} state
 *   Info passed around about the current state.
 * @returns {string}
 *   Serialized node.
 */
function raw$1(node, index, parent, state) {
  return state.settings.allowDangerousHtml
    ? node.value
    : text$2(node, index, parent, state)
}

/**
 * @import {Parents, Root} from 'hast'
 * @import {State} from '../index.js'
 */

/**
 * Serialize a root.
 *
 * @param {Root} node
 *   Node to handle.
 * @param {number | undefined} _1
 *   Index of `node` in `parent.
 * @param {Parents | undefined} _2
 *   Parent of `node`.
 * @param {State} state
 *   Info passed around about the current state.
 * @returns {string}
 *   Serialized node.
 */
function root$1(node, _1, _2, state) {
  return state.all(node)
}

/**
 * @import {Nodes, Parents} from 'hast'
 * @import {State} from '../index.js'
 */


/**
 * @type {(node: Nodes, index: number | undefined, parent: Parents | undefined, state: State) => string}
 */
const handle$1 = zwitch('type', {
  invalid,
  unknown,
  handlers: {comment, doctype, element, raw: raw$1, root: root$1, text: text$2}
});

/**
 * Fail when a non-node is found in the tree.
 *
 * @param {unknown} node
 *   Unknown value.
 * @returns {never}
 *   Never.
 */
function invalid(node) {
  throw new Error('Expected node, not `' + node + '`')
}

/**
 * Fail when a node with an unknown type is found in the tree.
 *
 * @param {unknown} node_
 *  Unknown node.
 * @returns {never}
 *   Never.
 */
function unknown(node_) {
  // `type` is guaranteed by runtime JS.
  const node = /** @type {Nodes} */ (node_);
  throw new Error('Cannot compile unknown node `' + node.type + '`')
}

/**
 * @import {Nodes, Parents, RootContent} from 'hast'
 * @import {Schema} from 'property-information'
 * @import {Options as StringifyEntitiesOptions} from 'stringify-entities'
 */


/** @type {Options} */
const emptyOptions$1 = {};

/** @type {CharacterReferences} */
const emptyCharacterReferences = {};

/** @type {Array<never>} */
const emptyChildren = [];

/**
 * Serialize hast as HTML.
 *
 * @param {Array<RootContent> | Nodes} tree
 *   Tree to serialize.
 * @param {Options | null | undefined} [options]
 *   Configuration (optional).
 * @returns {string}
 *   Serialized HTML.
 */
function toHtml(tree, options) {
  const options_ = options || emptyOptions$1;
  const quote = options_.quote || '"';
  const alternative = quote === '"' ? "'" : '"';

  if (quote !== '"' && quote !== "'") {
    throw new Error('Invalid quote `' + quote + '`, expected `\'` or `"`')
  }

  /** @type {State} */
  const state = {
    one: one$1,
    all: all$1,
    settings: {
      omitOptionalTags: options_.omitOptionalTags || false,
      allowParseErrors: options_.allowParseErrors || false,
      allowDangerousCharacters: options_.allowDangerousCharacters || false,
      quoteSmart: options_.quoteSmart || false,
      preferUnquote