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

6 files changed, 1667 insertions, 0 deletions

diff --git a/vanilla/node_modules/undici/lib/util/cache.js b/vanilla/node_modules/undici/lib/util/cache.js
new file mode 100644
index 0000000..b7627d0
--- /dev/null
+++ b/vanilla/node_modules/undici/lib/util/cache.js
@@ -0,0 +1,405 @@
+'use strict'
+
+const {
+  safeHTTPMethods,
+  pathHasQueryOrFragment
+} = require('../core/util')
+
+const { serializePathWithQuery } = require('../core/util')
+
+/**
+ * @param {import('../../types/dispatcher.d.ts').default.DispatchOptions} opts
+ */
+function makeCacheKey (opts) {
+  if (!opts.origin) {
+    throw new Error('opts.origin is undefined')
+  }
+
+  let fullPath = opts.path || '/'
+
+  if (opts.query && !pathHasQueryOrFragment(opts.path)) {
+    fullPath = serializePathWithQuery(fullPath, opts.query)
+  }
+
+  return {
+    origin: opts.origin.toString(),
+    method: opts.method,
+    path: fullPath,
+    headers: opts.headers
+  }
+}
+
+/**
+ * @param {Record<string, string[] | string>}
+ * @returns {Record<string, string[] | string>}
+ */
+function normalizeHeaders (opts) {
+  let headers
+  if (opts.headers == null) {
+    headers = {}
+  } else if (typeof opts.headers[Symbol.iterator] === 'function') {
+    headers = {}
+    for (const x of opts.headers) {
+      if (!Array.isArray(x)) {
+        throw new Error('opts.headers is not a valid header map')
+      }
+      const [key, val] = x
+      if (typeof key !== 'string' || typeof val !== 'string') {
+        throw new Error('opts.headers is not a valid header map')
+      }
+      headers[key.toLowerCase()] = val
+    }
+  } else if (typeof opts.headers === 'object') {
+    headers = {}
+
+    for (const key of Object.keys(opts.headers)) {
+      headers[key.toLowerCase()] = opts.headers[key]
+    }
+  } else {
+    throw new Error('opts.headers is not an object')
+  }
+
+  return headers
+}
+
+/**
+ * @param {any} key
+ */
+function assertCacheKey (key) {
+  if (typeof key !== 'object') {
+    throw new TypeError(`expected key to be object, got ${typeof key}`)
+  }
+
+  for (const property of ['origin', 'method', 'path']) {
+    if (typeof key[property] !== 'string') {
+      throw new TypeError(`expected key.${property} to be string, got ${typeof key[property]}`)
+    }
+  }
+
+  if (key.headers !== undefined && typeof key.headers !== 'object') {
+    throw new TypeError(`expected headers to be object, got ${typeof key}`)
+  }
+}
+
+/**
+ * @param {any} value
+ */
+function assertCacheValue (value) {
+  if (typeof value !== 'object') {
+    throw new TypeError(`expected value to be object, got ${typeof value}`)
+  }
+
+  for (const property of ['statusCode', 'cachedAt', 'staleAt', 'deleteAt']) {
+    if (typeof value[property] !== 'number') {
+      throw new TypeError(`expected value.${property} to be number, got ${typeof value[property]}`)
+    }
+  }
+
+  if (typeof value.statusMessage !== 'string') {
+    throw new TypeError(`expected value.statusMessage to be string, got ${typeof value.statusMessage}`)
+  }
+
+  if (value.headers != null && typeof value.headers !== 'object') {
+    throw new TypeError(`expected value.rawHeaders to be object, got ${typeof value.headers}`)
+  }
+
+  if (value.vary !== undefined && typeof value.vary !== 'object') {
+    throw new TypeError(`expected value.vary to be object, got ${typeof value.vary}`)
+  }
+
+  if (value.etag !== undefined && typeof value.etag !== 'string') {
+    throw new TypeError(`expected value.etag to be string, got ${typeof value.etag}`)
+  }
+}
+
+/**
+ * @see https://www.rfc-editor.org/rfc/rfc9111.html#name-cache-control
+ * @see https://www.iana.org/assignments/http-cache-directives/http-cache-directives.xhtml
+
+ * @param {string | string[]} header
+ * @returns {import('../../types/cache-interceptor.d.ts').default.CacheControlDirectives}
+ */
+function parseCacheControlHeader (header) {
+  /**
+   * @type {import('../../types/cache-interceptor.d.ts').default.CacheControlDirectives}
+   */
+  const output = {}
+
+  let directives
+  if (Array.isArray(header)) {
+    directives = []
+
+    for (const directive of header) {
+      directives.push(...directive.split(','))
+    }
+  } else {
+    directives = header.split(',')
+  }
+
+  for (let i = 0; i < directives.length; i++) {
+    const directive = directives[i].toLowerCase()
+    const keyValueDelimiter = directive.indexOf('=')
+
+    let key
+    let value
+    if (keyValueDelimiter !== -1) {
+      key = directive.substring(0, keyValueDelimiter).trimStart()
+      value = directive.substring(keyValueDelimiter + 1)
+    } else {
+      key = directive.trim()
+    }
+
+    switch (key) {
+      case 'min-fresh':
+      case 'max-stale':
+      case 'max-age':
+      case 's-maxage':
+      case 'stale-while-revalidate':
+      case 'stale-if-error': {
+        if (value === undefined || value[0] === ' ') {
+          continue
+        }
+
+        if (
+          value.length >= 2 &&
+          value[0] === '"' &&
+          value[value.length - 1] === '"'
+        ) {
+          value = value.substring(1, value.length - 1)
+        }
+
+        const parsedValue = parseInt(value, 10)
+        // eslint-disable-next-line no-self-compare
+        if (parsedValue !== parsedValue) {
+          continue
+        }
+
+        if (key === 'max-age' && key in output && output[key] >= parsedValue) {
+          continue
+        }
+
+        output[key] = parsedValue
+
+        break
+      }
+      case 'private':
+      case 'no-cache': {
+        if (value) {
+          // The private and no-cache directives can be unqualified (aka just
+          //  `private` or `no-cache`) or qualified (w/ a value). When they're
+          //  qualified, it's a list of headers like `no-cache=header1`,
+          //  `no-cache="header1"`, or `no-cache="header1, header2"`
+          // If we're given multiple headers, the comma messes us up since
+          //  we split the full header by commas. So, let's loop through the
+          //  remaining parts in front of us until we find one that ends in a
+          //  quote. We can then just splice all of the parts in between the
+          //  starting quote and the ending quote out of the directives array
+          //  and continue parsing like normal.
+          // https://www.rfc-editor.org/rfc/rfc9111.html#name-no-cache-2
+          if (value[0] === '"') {
+            // Something like `no-cache="some-header"` OR `no-cache="some-header, another-header"`.
+
+            // Add the first header on and cut off the leading quote
+            const headers = [value.substring(1)]
+
+            let foundEndingQuote = value[value.length - 1] === '"'
+            if (!foundEndingQuote) {
+              // Something like `no-cache="some-header, another-header"`
+              //  This can still be something invalid, e.g. `no-cache="some-header, ...`
+              for (let j = i + 1; j < directives.length; j++) {
+                const nextPart = directives[j]
+                const nextPartLength = nextPart.length
+
+                headers.push(nextPart.trim())
+
+                if (nextPartLength !== 0 && nextPart[nextPartLength - 1] === '"') {
+                  foundEndingQuote = true
+                  break
+                }
+              }
+            }
+
+            if (foundEndingQuote) {
+              let lastHeader = headers[headers.length - 1]
+              if (lastHeader[lastHeader.length - 1] === '"') {
+                lastHeader = lastHeader.substring(0, lastHeader.length - 1)
+                headers[headers.length - 1] = lastHeader
+              }
+
+              if (key in output) {
+                output[key] = output[key].concat(headers)
+              } else {
+                output[key] = headers
+              }
+            }
+          } else {
+            // Something like `no-cache="some-header"`
+            if (key in output) {
+              output[key] = output[key].concat(value)
+            } else {
+              output[key] = [value]
+            }
+          }
+
+          break
+        }
+      }
+      // eslint-disable-next-line no-fallthrough
+      case 'public':
+      case 'no-store':
+      case 'must-revalidate':
+      case 'proxy-revalidate':
+      case 'immutable':
+      case 'no-transform':
+      case 'must-understand':
+      case 'only-if-cached':
+        if (value) {
+          // These are qualified (something like `public=...`) when they aren't
+          //  allowed to be, skip
+          continue
+        }
+
+        output[key] = true
+        break
+      default:
+        // Ignore unknown directives as per https://www.rfc-editor.org/rfc/rfc9111.html#section-5.2.3-1
+        continue
+    }
+  }
+
+  return output
+}
+
+/**
+ * @param {string | string[]} varyHeader Vary header from the server
+ * @param {Record<string, string | string[]>} headers Request headers
+ * @returns {Record<string, string | string[]>}
+ */
+function parseVaryHeader (varyHeader, headers) {
+  if (typeof varyHeader === 'string' && varyHeader.includes('*')) {
+    return headers
+  }
+
+  const output = /** @type {Record<string, string | string[] | null>} */ ({})
+
+  const varyingHeaders = typeof varyHeader === 'string'
+    ? varyHeader.split(',')
+    : varyHeader
+
+  for (const header of varyingHeaders) {
+    const trimmedHeader = header.trim().toLowerCase()
+
+    output[trimmedHeader] = headers[trimmedHeader] ?? null
+  }
+
+  return output
+}
+
+/**
+ * Note: this deviates from the spec a little. Empty etags ("", W/"") are valid,
+ *  however, including them in cached resposnes serves little to no purpose.
+ *
+ * @see https://www.rfc-editor.org/rfc/rfc9110.html#name-etag
+ *
+ * @param {string} etag
+ * @returns {boolean}
+ */
+function isEtagUsable (etag) {
+  if (etag.length <= 2) {
+    // Shortest an etag can be is two chars (just ""). This is where we deviate
+    //  from the spec requiring a min of 3 chars however
+    return false
+  }
+
+  if (etag[0] === '"' && etag[etag.length - 1] === '"') {
+    // ETag: ""asd123"" or ETag: "W/"asd123"", kinda undefined behavior in the
+    //  spec. Some servers will accept these while others don't.
+    // ETag: "asd123"
+    return !(etag[1] === '"' || etag.startsWith('"W/'))
+  }
+
+  if (etag.startsWith('W/"') && etag[etag.length - 1] === '"') {
+    // ETag: W/"", also where we deviate from the spec & require a min of 3
+    //  chars
+    // ETag: for W/"", W/"asd123"
+    return etag.length !== 4
+  }
+
+  // Anything else
+  return false
+}
+
+/**
+ * @param {unknown} store
+ * @returns {asserts store is import('../../types/cache-interceptor.d.ts').default.CacheStore}
+ */
+function assertCacheStore (store, name = 'CacheStore') {
+  if (typeof store !== 'object' || store === null) {
+    throw new TypeError(`expected type of ${name} to be a CacheStore, got ${store === null ? 'null' : typeof store}`)
+  }
+
+  for (const fn of ['get', 'createWriteStream', 'delete']) {
+    if (typeof store[fn] !== 'function') {
+      throw new TypeError(`${name} needs to have a \`${fn}()\` function`)
+    }
+  }
+}
+/**
+ * @param {unknown} methods
+ * @returns {asserts methods is import('../../types/cache-interceptor.d.ts').default.CacheMethods[]}
+ */
+function assertCacheMethods (methods, name = 'CacheMethods') {
+  if (!Array.isArray(methods)) {
+    throw new TypeError(`expected type of ${name} needs to be an array, got ${methods === null ? 'null' : typeof methods}`)
+  }
+
+  if (methods.length === 0) {
+    throw new TypeError(`${name} needs to have at least one method`)
+  }
+
+  for (const method of methods) {
+    if (!safeHTTPMethods.includes(method)) {
+      throw new TypeError(`element of ${name}-array needs to be one of following values: ${safeHTTPMethods.join(', ')}, got ${method}`)
+    }
+  }
+}
+
+/**
+ * Creates a string key for request deduplication purposes.
+ * This key is used to identify in-flight requests that can be shared.
+ * @param {import('../../types/cache-interceptor.d.ts').default.CacheKey} cacheKey
+ * @param {Set<string>} [excludeHeaders] Set of lowercase header names to exclude from the key
+ * @returns {string}
+ */
+function makeDeduplicationKey (cacheKey, excludeHeaders) {
+  // Create a deterministic string key from the cache key
+  // Include origin, method, path, and sorted headers
+  let key = `${cacheKey.origin}:${cacheKey.method}:${cacheKey.path}`
+
+  if (cacheKey.headers) {
+    const sortedHeaders = Object.keys(cacheKey.headers).sort()
+    for (const header of sortedHeaders) {
+      // Skip excluded headers
+      if (excludeHeaders?.has(header.toLowerCase())) {
+        continue
+      }
+      const value = cacheKey.headers[header]
+      key += `:${header}=${Array.isArray(value) ? value.join(',') : value}`
+    }
+  }
+
+  return key
+}
+
+module.exports = {
+  makeCacheKey,
+  normalizeHeaders,
+  assertCacheKey,
+  assertCacheValue,
+  parseCacheControlHeader,
+  parseVaryHeader,
+  isEtagUsable,
+  assertCacheMethods,
+  assertCacheStore,
+  makeDeduplicationKey
+}
diff --git a/vanilla/node_modules/undici/lib/util/date.js b/vanilla/node_modules/undici/lib/util/date.js
new file mode 100644
index 0000000..99dd150
--- /dev/null
+++ b/vanilla/node_modules/undici/lib/util/date.js
@@ -0,0 +1,653 @@
+'use strict'
+
+/**
+ * @see https://www.rfc-editor.org/rfc/rfc9110.html#name-date-time-formats
+ *
+ * @param {string} date
+ * @returns {Date | undefined}
+ */
+function parseHttpDate (date) {
+  // Sun, 06 Nov 1994 08:49:37 GMT    ; IMF-fixdate
+  // Sun Nov  6 08:49:37 1994         ; ANSI C's asctime() format
+  // Sunday, 06-Nov-94 08:49:37 GMT   ; obsolete RFC 850 format
+
+  switch (date[3]) {
+    case ',': return parseImfDate(date)
+    case ' ': return parseAscTimeDate(date)
+    default: return parseRfc850Date(date)
+  }
+}
+
+/**
+ * @see https://httpwg.org/specs/rfc9110.html#preferred.date.format
+ *
+ * @param {string} date
+ * @returns {Date | undefined}
+ */
+function parseImfDate (date) {
+  if (
+    date.length !== 29 ||
+    date[4] !== ' ' ||
+    date[7] !== ' ' ||
+    date[11] !== ' ' ||
+    date[16] !== ' ' ||
+    date[19] !== ':' ||
+    date[22] !== ':' ||
+    date[25] !== ' ' ||
+    date[26] !== 'G' ||
+    date[27] !== 'M' ||
+    date[28] !== 'T'
+  ) {
+    return undefined
+  }
+
+  let weekday = -1
+  if (date[0] === 'S' && date[1] === 'u' && date[2] === 'n') { // Sunday
+    weekday = 0
+  } else if (date[0] === 'M' && date[1] === 'o' && date[2] === 'n') { // Monday
+    weekday = 1
+  } else if (date[0] === 'T' && date[1] === 'u' && date[2] === 'e') { // Tuesday
+    weekday = 2
+  } else if (date[0] === 'W' && date[1] === 'e' && date[2] === 'd') { // Wednesday
+    weekday = 3
+  } else if (date[0] === 'T' && date[1] === 'h' && date[2] === 'u') { // Thursday
+    weekday = 4
+  } else if (date[0] === 'F' && date[1] === 'r' && date[2] === 'i') { // Friday
+    weekday = 5
+  } else if (date[0] === 'S' && date[1] === 'a' && date[2] === 't') { // Saturday
+    weekday = 6
+  } else {
+    return undefined // Not a valid day of the week
+  }
+
+  let day = 0
+  if (date[5] === '0') {
+    // Single digit day, e.g. "Sun Nov 6 08:49:37 1994"
+    const code = date.charCodeAt(6)
+    if (code < 49 || code > 57) {
+      return undefined // Not a digit
+    }
+    day = code - 48 // Convert ASCII code to number
+  } else {
+    const code1 = date.charCodeAt(5)
+    if (code1 < 49 || code1 > 51) {
+      return undefined // Not a digit between 1 and 3
+    }
+    const code2 = date.charCodeAt(6)
+    if (code2 < 48 || code2 > 57) {
+      return undefined // Not a digit
+    }
+    day = (code1 - 48) * 10 + (code2 - 48) // Convert ASCII codes to number
+  }
+
+  let monthIdx = -1
+  if (
+    (date[8] === 'J' && date[9] === 'a' && date[10] === 'n')
+  ) {
+    monthIdx = 0 // Jan
+  } else if (
+    (date[8] === 'F' && date[9] === 'e' && date[10] === 'b')
+  ) {
+    monthIdx = 1 // Feb
+  } else if (
+    (date[8] === 'M' && date[9] === 'a')
+  ) {
+    if (date[10] === 'r') {
+      monthIdx = 2 // Mar
+    } else if (date[10] === 'y') {
+      monthIdx = 4 // May
+    } else {
+      return undefined // Invalid month
+    }
+  } else if (
+    (date[8] === 'J')
+  ) {
+    if (date[9] === 'a' && date[10] === 'n') {
+      monthIdx = 0 // Jan
+    } else if (date[9] === 'u') {
+      if (date[10] === 'n') {
+        monthIdx = 5 // Jun
+      } else if (date[10] === 'l') {
+        monthIdx = 6 // Jul
+      } else {
+        return undefined // Invalid month
+      }
+    } else {
+      return undefined // Invalid month
+    }
+  } else if (
+    (date[8] === 'A')
+  ) {
+    if (date[9] === 'p' && date[10] === 'r') {
+      monthIdx = 3 // Apr
+    } else if (date[9] === 'u' && date[10] === 'g') {
+      monthIdx = 7 // Aug
+    } else {
+      return undefined // Invalid month
+    }
+  } else if (
+    (date[8] === 'S' && date[9] === 'e' && date[10] === 'p')
+  ) {
+    monthIdx = 8 // Sep
+  } else if (
+    (date[8] === 'O' && date[9] === 'c' && date[10] === 't')
+  ) {
+    monthIdx = 9 // Oct
+  } else if (
+    (date[8] === 'N' && date[9] === 'o' && date[10] === 'v')
+  ) {
+    monthIdx = 10 // Nov
+  } else if (
+    (date[8] === 'D' && date[9] === 'e' && date[10] === 'c')
+  ) {
+    monthIdx = 11 // Dec
+  } else {
+    // Not a valid month
+    return undefined
+  }
+
+  const yearDigit1 = date.charCodeAt(12)
+  if (yearDigit1 < 48 || yearDigit1 > 57) {
+    return undefined // Not a digit
+  }
+  const yearDigit2 = date.charCodeAt(13)
+  if (yearDigit2 < 48 || yearDigit2 > 57) {
+    return undefined // Not a digit
+  }
+  const yearDigit3 = date.charCodeAt(14)
+  if (yearDigit3 < 48 || yearDigit3 > 57) {
+    return undefined // Not a digit
+  }
+  const yearDigit4 = date.charCodeAt(15)
+  if (yearDigit4 < 48 || yearDigit4 > 57) {
+    return undefined // Not a digit
+  }
+  const year = (yearDigit1 - 48) * 1000 + (yearDigit2 - 48) * 100 + (yearDigit3 - 48) * 10 + (yearDigit4 - 48)
+
+  let hour = 0
+  if (date[17] === '0') {
+    const code = date.charCodeAt(18)
+    if (code < 48 || code > 57) {
+      return undefined // Not a digit
+    }
+    hour = code - 48 // Convert ASCII code to number
+  } else {
+    const code1 = date.charCodeAt(17)
+    if (code1 < 48 || code1 > 50) {
+      return undefined // Not a digit between 0 and 2
+    }
+    const code2 = date.charCodeAt(18)
+    if (code2 < 48 || code2 > 57) {
+      return undefined // Not a digit
+    }
+    if (code1 === 50 && code2 > 51) {
+      return undefined // Hour cannot be greater than 23
+    }
+    hour = (code1 - 48) * 10 + (code2 - 48) // Convert ASCII codes to number
+  }
+
+  let minute = 0
+  if (date[20] === '0') {
+    const code = date.charCodeAt(21)
+    if (code < 48 || code > 57) {
+      return undefined // Not a digit
+    }
+    minute = code - 48 // Convert ASCII code to number
+  } else {
+    const code1 = date.charCodeAt(20)
+    if (code1 < 48 || code1 > 53) {
+      return undefined // Not a digit between 0 and 5
+    }
+    const code2 = date.charCodeAt(21)
+    if (code2 < 48 || code2 > 57) {
+      return undefined // Not a digit
+    }
+    minute = (code1 - 48) * 10 + (code2 - 48) // Convert ASCII codes to number
+  }
+
+  let second = 0
+  if (date[23] === '0') {
+    const code = date.charCodeAt(24)
+    if (code < 48 || code > 57) {
+      return undefined // Not a digit
+    }
+    second = code - 48 // Convert ASCII code to number
+  } else {
+    const code1 = date.charCodeAt(23)
+    if (code1 < 48 || code1 > 53) {
+      return undefined // Not a digit between 0 and 5
+    }
+    const code2 = date.charCodeAt(24)
+    if (code2 < 48 || code2 > 57) {
+      return undefined // Not a digit
+    }
+    second = (code1 - 48) * 10 + (code2 - 48) // Convert ASCII codes to number
+  }
+
+  const result = new Date(Date.UTC(year, monthIdx, day, hour, minute, second))
+  return result.getUTCDay() === weekday ? result : undefined
+}
+
+/**
+ * @see https://httpwg.org/specs/rfc9110.html#obsolete.date.formats
+ *
+ * @param {string} date
+ * @returns {Date | undefined}
+ */
+function parseAscTimeDate (date) {
+  // This is assumed to be in UTC
+
+  if (
+    date.length !== 24 ||
+    date[7] !== ' ' ||
+    date[10] !== ' ' ||
+    date[19] !== ' '
+  ) {
+    return undefined
+  }
+
+  let weekday = -1
+  if (date[0] === 'S' && date[1] === 'u' && date[2] === 'n') { // Sunday
+    weekday = 0
+  } else if (date[0] === 'M' && date[1] === 'o' && date[2] === 'n') { // Monday
+    weekday = 1
+  } else if (date[0] === 'T' && date[1] === 'u' && date[2] === 'e') { // Tuesday
+    weekday = 2
+  } else if (date[0] === 'W' && date[1] === 'e' && date[2] === 'd') { // Wednesday
+    weekday = 3
+  } else if (date[0] === 'T' && date[1] === 'h' && date[2] === 'u') { // Thursday
+    weekday = 4
+  } else if (date[0] === 'F' && date[1] === 'r' && date[2] === 'i') { // Friday
+    weekday = 5
+  } else if (date[0] === 'S' && date[1] === 'a' && date[2] === 't') { // Saturday
+    weekday = 6
+  } else {
+    return undefined // Not a valid day of the week
+  }
+
+  let monthIdx = -1
+  if (
+    (date[4] === 'J' && date[5] === 'a' && date[6] === 'n')
+  ) {
+    monthIdx = 0 // Jan
+  } else if (
+    (date[4] === 'F' && date[5] === 'e' && date[6] === 'b')
+  ) {
+    monthIdx = 1 // Feb
+  } else if (
+    (date[4] === 'M' && date[5] === 'a')
+  ) {
+    if (date[6] === 'r') {
+      monthIdx = 2 // Mar
+    } else if (date[6] === 'y') {
+      monthIdx = 4 // May
+    } else {
+      return undefined // Invalid month
+    }
+  } else if (
+    (date[4] === 'J')
+  ) {
+    if (date[5] === 'a' && date[6] === 'n') {
+      monthIdx = 0 // Jan
+    } else if (date[5] === 'u') {
+      if (date[6] === 'n') {
+        monthIdx = 5 // Jun
+      } else if (date[6] === 'l') {
+        monthIdx = 6 // Jul
+      } else {
+        return undefined // Invalid month
+      }
+    } else {
+      return undefined // Invalid month
+    }
+  } else if (
+    (date[4] === 'A')
+  ) {
+    if (date[5] === 'p' && date[6] === 'r') {
+      monthIdx = 3 // Apr
+    } else if (date[5] === 'u' && date[6] === 'g') {
+      monthIdx = 7 // Aug
+    } else {
+      return undefined // Invalid month
+    }
+  } else if (
+    (date[4] === 'S' && date[5] === 'e' && date[6] === 'p')
+  ) {
+    monthIdx = 8 // Sep
+  } else if (
+    (date[4] === 'O' && date[5] === 'c' && date[6] === 't')
+  ) {
+    monthIdx = 9 // Oct
+  } else if (
+    (date[4] === 'N' && date[5] === 'o' && date[6] === 'v')
+  ) {
+    monthIdx = 10 // Nov
+  } else if (
+    (date[4] === 'D' && date[5] === 'e' && date[6] === 'c')
+  ) {
+    monthIdx = 11 // Dec
+  } else {
+    // Not a valid month
+    return undefined
+  }
+
+  let day = 0
+  if (date[8] === ' ') {
+    // Single digit day, e.g. "Sun Nov 6 08:49:37 1994"
+    const code = date.charCodeAt(9)
+    if (code < 49 || code > 57) {
+      return undefined // Not a digit
+    }
+    day = code - 48 // Convert ASCII code to number
+  } else {
+    const code1 = date.charCodeAt(8)
+    if (code1 < 49 || code1 > 51) {
+      return undefined // Not a digit between 1 and 3
+    }
+    const code2 = date.charCodeAt(9)
+    if (code2 < 48 || code2 > 57) {
+      return undefined // Not a digit
+    }
+    day = (code1 - 48) * 10 + (code2 - 48) // Convert ASCII codes to number
+  }
+
+  let hour = 0
+  if (date[11] === '0') {
+    const code = date.charCodeAt(12)
+    if (code < 48 || code > 57) {
+      return undefined // Not a digit
+    }
+    hour = code - 48 // Convert ASCII code to number
+  } else {
+    const code1 = date.charCodeAt(11)
+    if (code1 < 48 || code1 > 50) {
+      return undefined // Not a digit between 0 and 2
+    }
+    const code2 = date.charCodeAt(12)
+    if (code2 < 48 || code2 > 57) {
+      return undefined // Not a digit
+    }
+    if (code1 === 50 && code2 > 51) {
+      return undefined // Hour cannot be greater than 23
+    }
+    hour = (code1 - 48) * 10 + (code2 - 48) // Convert ASCII codes to number
+  }
+
+  let minute = 0
+  if (date[14] === '0') {
+    const code = date.charCodeAt(15)
+    if (code < 48 || code > 57) {
+      return undefined // Not a digit
+    }
+    minute = code - 48 // Convert ASCII code to number
+  } else {
+    const code1 = date.charCodeAt(14)
+    if (code1 < 48 || code1 > 53) {
+      return undefined // Not a digit between 0 and 5
+    }
+    const code2 = date.charCodeAt(15)
+    if (code2 < 48 || code2 > 57) {
+      return undefined // Not a digit
+    }
+    minute = (code1 - 48) * 10 + (code2 - 48) // Convert ASCII codes to number
+  }
+
+  let second = 0
+  if (date[17] === '0') {
+    const code = date.charCodeAt(18)
+    if (code < 48 || code > 57) {
+      return undefined // Not a digit
+    }
+    second = code - 48 // Convert ASCII code to number
+  } else {
+    const code1 = date.charCodeAt(17)
+    if (code1 < 48 || code1 > 53) {
+      return undefined // Not a digit between 0 and 5
+    }
+    const code2 = date.charCodeAt(18)
+    if (code2 < 48 || code2 > 57) {
+      return undefined // Not a digit
+    }
+    second = (code1 - 48) * 10 + (code2 - 48) // Convert ASCII codes to number
+  }
+
+  const yearDigit1 = date.charCodeAt(20)
+  if (yearDigit1 < 48 || yearDigit1 > 57) {
+    return undefined // Not a digit
+  }
+  const yearDigit2 = date.charCodeAt(21)
+  if (yearDigit2 < 48 || yearDigit2 > 57) {
+    return undefined // Not a digit
+  }
+  const yearDigit3 = date.charCodeAt(22)
+  if (yearDigit3 < 48 || yearDigit3 > 57) {
+    return undefined // Not a digit
+  }
+  const yearDigit4 = date.charCodeAt(23)
+  if (yearDigit4 < 48 || yearDigit4 > 57) {
+    return undefined // Not a digit
+  }
+  const year = (yearDigit1 - 48) * 1000 + (yearDigit2 - 48) * 100 + (yearDigit3 - 48) * 10 + (yearDigit4 - 48)
+
+  const result = new Date(Date.UTC(year, monthIdx, day, hour, minute, second))
+  return result.getUTCDay() === weekday ? result : undefined
+}
+
+/**
+ * @see https://httpwg.org/specs/rfc9110.html#obsolete.date.formats
+ *
+ * @param {string} date
+ * @returns {Date | undefined}
+ */
+function parseRfc850Date (date) {
+  let commaIndex = -1
+
+  let weekday = -1
+  if (date[0] === 'S') {
+    if (date[1] === 'u' && date[2] === 'n' && date[3] === 'd' && date[4] === 'a' && date[5] === 'y') {
+      weekday = 0 // Sunday
+      commaIndex = 6
+    } else if (date[1] === 'a' && date[2] === 't' && date[3] === 'u' && date[4] === 'r' && date[5] === 'd' && date[6] === 'a' && date[7] === 'y') {
+      weekday = 6 // Saturday
+      commaIndex = 8
+    }
+  } else if (date[0] === 'M' && date[1] === 'o' && date[2] === 'n' && date[3] === 'd' && date[4] === 'a' && date[5] === 'y') {
+    weekday = 1 // Monday
+    commaIndex = 6
+  } else if (date[0] === 'T') {
+    if (date[1] === 'u' && date[2] === 'e' && date[3] === 's' && date[4] === 'd' && date[5] === 'a' && date[6] === 'y') {
+      weekday = 2 // Tuesday
+      commaIndex = 7
+    } else if (date[1] === 'h' && date[2] === 'u' && date[3] === 'r' && date[4] === 's' && date[5] === 'd' && date[6] === 'a' && date[7] === 'y') {
+      weekday = 4 // Thursday
+      commaIndex = 8
+    }
+  } else if (date[0] === 'W' && date[1] === 'e' && date[2] === 'd' && date[3] === 'n' && date[4] === 'e' && date[5] === 's' && date[6] === 'd' && date[7] === 'a' && date[8] === 'y') {
+    weekday = 3 // Wednesday
+    commaIndex = 9
+  } else if (date[0] === 'F' && date[1] === 'r' && date[2] === 'i' && date[3] === 'd' && date[4] === 'a' && date[5] === 'y') {
+    weekday = 5 // Friday
+    commaIndex = 6
+  } else {
+    // Not a valid day name
+    return undefined
+  }
+
+  if (
+    date[commaIndex] !== ',' ||
+    (date.length - commaIndex - 1) !== 23 ||
+    date[commaIndex + 1] !== ' ' ||
+    date[commaIndex + 4] !== '-' ||
+    date[commaIndex + 8] !== '-' ||
+    date[commaIndex + 11] !== ' ' ||
+    date[commaIndex + 14] !== ':' ||
+    date[commaIndex + 17] !== ':' ||
+    date[commaIndex + 20] !== ' ' ||
+    date[commaIndex + 21] !== 'G' ||
+    date[commaIndex + 22] !== 'M' ||
+    date[commaIndex + 23] !== 'T'
+  ) {
+    return undefined
+  }
+
+  let day = 0
+  if (date[commaIndex + 2] === '0') {
+    // Single digit day, e.g. "Sun Nov 6 08:49:37 1994"
+    const code = date.charCodeAt(commaIndex + 3)
+    if (code < 49 || code > 57) {
+      return undefined // Not a digit
+    }
+    day = code - 48 // Convert ASCII code to number
+  } else {
+    const code1 = date.charCodeAt(commaIndex + 2)
+    if (code1 < 49 || code1 > 51) {
+      return undefined // Not a digit between 1 and 3
+    }
+    const code2 = date.charCodeAt(commaIndex + 3)
+    if (code2 < 48 || code2 > 57) {
+      return undefined // Not a digit
+    }
+    day = (code1 - 48) * 10 + (code2 - 48) // Convert ASCII codes to number
+  }
+
+  let monthIdx = -1
+  if (
+    (date[commaIndex + 5] === 'J' && date[commaIndex + 6] === 'a' && date[commaIndex + 7] === 'n')
+  ) {
+    monthIdx = 0 // Jan
+  } else if (
+    (date[commaIndex + 5] === 'F' && date[commaIndex + 6] === 'e' && date[commaIndex + 7] === 'b')
+  ) {
+    monthIdx = 1 // Feb
+  } else if (
+    (date[commaIndex + 5] === 'M' && date[commaIndex + 6] === 'a' && date[commaIndex + 7] === 'r')
+  ) {
+    monthIdx = 2 // Mar
+  } else if (
+    (date[commaIndex + 5] === 'A' && date[commaIndex + 6] === 'p' && date[commaIndex + 7] === 'r')
+  ) {
+    monthIdx = 3 // Apr
+  } else if (
+    (date[commaIndex + 5] === 'M' && date[commaIndex + 6] === 'a' && date[commaIndex + 7] === 'y')
+  ) {
+    monthIdx = 4 // May
+  } else if (
+    (date[commaIndex + 5] === 'J' && date[commaIndex + 6] === 'u' && date[commaIndex + 7] === 'n')
+  ) {
+    monthIdx = 5 // Jun
+  } else if (
+    (date[commaIndex + 5] === 'J' && date[commaIndex + 6] === 'u' && date[commaIndex + 7] === 'l')
+  ) {
+    monthIdx = 6 // Jul
+  } else if (
+    (date[commaIndex + 5] === 'A' && date[commaIndex + 6] === 'u' && date[commaIndex + 7] === 'g')
+  ) {
+    monthIdx = 7 // Aug
+  } else if (
+    (date[commaIndex + 5] === 'S' && date[commaIndex + 6] === 'e' && date[commaIndex + 7] === 'p')
+  ) {
+    monthIdx = 8 // Sep
+  } else if (
+    (date[commaIndex + 5] === 'O' && date[commaIndex + 6] === 'c' && date[commaIndex + 7] === 't')
+  ) {
+    monthIdx = 9 // Oct
+  } else if (
+    (date[commaIndex + 5] === 'N' && date[commaIndex + 6] === 'o' && date[commaIndex + 7] === 'v')
+  ) {
+    monthIdx = 10 // Nov
+  } else if (
+    (date[commaIndex + 5] === 'D' && date[commaIndex + 6] === 'e' && date[commaIndex + 7] === 'c')
+  ) {
+    monthIdx = 11 // Dec
+  } else {
+    // Not a valid month
+    return undefined
+  }
+
+  const yearDigit1 = date.charCodeAt(commaIndex + 9)
+  if (yearDigit1 < 48 || yearDigit1 > 57) {
+    return undefined // Not a digit
+  }
+  const yearDigit2 = date.charCodeAt(commaIndex + 10)
+  if (yearDigit2 < 48 || yearDigit2 > 57) {
+    return undefined // Not a digit
+  }
+
+  let year = (yearDigit1 - 48) * 10 + (yearDigit2 - 48) // Convert ASCII codes to number
+
+  // RFC 6265 states that the year is in the range 1970-2069.
+  // @see https://datatracker.ietf.org/doc/html/rfc6265#section-5.1.1
+  //
+  // 3. If the year-value is greater than or equal to 70 and less than or
+  //    equal to 99, increment the year-value by 1900.
+  // 4. If the year-value is greater than or equal to 0 and less than or
+  //    equal to 69, increment the year-value by 2000.
+  year += year < 70 ? 2000 : 1900
+
+  let hour = 0
+  if (date[commaIndex + 12] === '0') {
+    const code = date.charCodeAt(commaIndex + 13)
+    if (code < 48 || code > 57) {
+      return undefined // Not a digit
+    }
+    hour = code - 48 // Convert ASCII code to number
+  } else {
+    const code1 = date.charCodeAt(commaIndex + 12)
+    if (code1 < 48 || code1 > 50) {
+      return undefined // Not a digit between 0 and 2
+    }
+    const code2 = date.charCodeAt(commaIndex + 13)
+    if (code2 < 48 || code2 > 57) {
+      return undefined // Not a digit
+    }
+    if (code1 === 50 && code2 > 51) {
+      return undefined // Hour cannot be greater than 23
+    }
+    hour = (code1 - 48) * 10 + (code2 - 48) // Convert ASCII codes to number
+  }
+
+  let minute = 0
+  if (date[commaIndex + 15] === '0') {
+    const code = date.charCodeAt(commaIndex + 16)
+    if (code < 48 || code > 57) {
+      return undefined // Not a digit
+    }
+    minute = code - 48 // Convert ASCII code to number
+  } else {
+    const code1 = date.charCodeAt(commaIndex + 15)
+    if (code1 < 48 || code1 > 53) {
+      return undefined // Not a digit between 0 and 5
+    }
+    const code2 = date.charCodeAt(commaIndex + 16)
+    if (code2 < 48 || code2 > 57) {
+      return undefined // Not a digit
+    }
+    minute = (code1 - 48) * 10 + (code2 - 48) // Convert ASCII codes to number
+  }
+
+  let second = 0
+  if (date[commaIndex + 18] === '0') {
+    const code = date.charCodeAt(commaIndex + 19)
+    if (code < 48 || code > 57) {
+      return undefined // Not a digit
+    }
+    second = code - 48 // Convert ASCII code to number
+  } else {
+    const code1 = date.charCodeAt(commaIndex + 18)
+    if (code1 < 48 || code1 > 53) {
+      return undefined // Not a digit between 0 and 5
+    }
+    const code2 = date.charCodeAt(commaIndex + 19)
+    if (code2 < 48 || code2 > 57) {
+      return undefined // Not a digit
+    }
+    second = (code1 - 48) * 10 + (code2 - 48) // Convert ASCII codes to number
+  }
+
+  const result = new Date(Date.UTC(year, monthIdx, day, hour, minute, second))
+  return result.getUTCDay() === weekday ? result : undefined
+}
+
+module.exports = {
+  parseHttpDate
+}
diff --git a/vanilla/node_modules/undici/lib/util/promise.js b/vanilla/node_modules/undici/lib/util/promise.js
new file mode 100644
index 0000000..048f86e
--- /dev/null
+++ b/vanilla/node_modules/undici/lib/util/promise.js
@@ -0,0 +1,28 @@
+'use strict'
+
+/**
+ * @template {*} T
+ * @typedef {Object} DeferredPromise
+ * @property {Promise<T>} promise
+ * @property {(value?: T) => void} resolve
+ * @property {(reason?: any) => void} reject
+ */
+
+/**
+ * @template {*} T
+ * @returns {DeferredPromise<T>} An object containing a promise and its resolve/reject methods.
+ */
+function createDeferredPromise () {
+  let res
+  let rej
+  const promise = new Promise((resolve, reject) => {
+    res = resolve
+    rej = reject
+  })
+
+  return { promise, resolve: res, reject: rej }
+}
+
+module.exports = {
+  createDeferredPromise
+}
diff --git a/vanilla/node_modules/undici/lib/util/runtime-features.js b/vanilla/node_modules/undici/lib/util/runtime-features.js
new file mode 100644
index 0000000..3e62dc0
--- /dev/null
+++ b/vanilla/node_modules/undici/lib/util/runtime-features.js
@@ -0,0 +1,124 @@
+'use strict'
+
+/** @typedef {`node:${string}`} NodeModuleName */
+
+/** @type {Record<NodeModuleName, () => any>} */
+const lazyLoaders = {
+  __proto__: null,
+  'node:crypto': () => require('node:crypto'),
+  'node:sqlite': () => require('node:sqlite'),
+  'node:worker_threads': () => require('node:worker_threads'),
+  'node:zlib': () => require('node:zlib')
+}
+
+/**
+ * @param {NodeModuleName} moduleName
+ * @returns {boolean}
+ */
+function detectRuntimeFeatureByNodeModule (moduleName) {
+  try {
+    lazyLoaders[moduleName]()
+    return true
+  } catch (err) {
+    if (err.code !== 'ERR_UNKNOWN_BUILTIN_MODULE' && err.code !== 'ERR_NO_CRYPTO') {
+      throw err
+    }
+    return false
+  }
+}
+
+/**
+ * @param {NodeModuleName} moduleName
+ * @param {string} property
+ * @returns {boolean}
+ */
+function detectRuntimeFeatureByExportedProperty (moduleName, property) {
+  const module = lazyLoaders[moduleName]()
+  return typeof module[property] !== 'undefined'
+}
+
+const runtimeFeaturesByExportedProperty = /** @type {const} */ (['markAsUncloneable', 'zstd'])
+
+/** @type {Record<RuntimeFeatureByExportedProperty, [NodeModuleName, string]>} */
+const exportedPropertyLookup = {
+  markAsUncloneable: ['node:worker_threads', 'markAsUncloneable'],
+  zstd: ['node:zlib', 'createZstdDecompress']
+}
+
+/** @typedef {typeof runtimeFeaturesByExportedProperty[number]} RuntimeFeatureByExportedProperty */
+
+const runtimeFeaturesAsNodeModule = /** @type {const} */ (['crypto', 'sqlite'])
+/** @typedef {typeof runtimeFeaturesAsNodeModule[number]} RuntimeFeatureByNodeModule */
+
+const features = /** @type {const} */ ([
+  ...runtimeFeaturesAsNodeModule,
+  ...runtimeFeaturesByExportedProperty
+])
+
+/** @typedef {typeof features[number]} Feature */
+
+/**
+ * @param {Feature} feature
+ * @returns {boolean}
+ */
+function detectRuntimeFeature (feature) {
+  if (runtimeFeaturesAsNodeModule.includes(/** @type {RuntimeFeatureByNodeModule} */ (feature))) {
+    return detectRuntimeFeatureByNodeModule(`node:${feature}`)
+  } else if (runtimeFeaturesByExportedProperty.includes(/** @type {RuntimeFeatureByExportedProperty} */ (feature))) {
+    const [moduleName, property] = exportedPropertyLookup[feature]
+    return detectRuntimeFeatureByExportedProperty(moduleName, property)
+  }
+  throw new TypeError(`unknown feature: ${feature}`)
+}
+
+/**
+ * @class
+ * @name RuntimeFeatures
+ */
+class RuntimeFeatures {
+  /** @type {Map<Feature, boolean>} */
+  #map = new Map()
+
+  /**
+   * Clears all cached feature detections.
+   */
+  clear () {
+    this.#map.clear()
+  }
+
+  /**
+   * @param {Feature} feature
+   * @returns {boolean}
+   */
+  has (feature) {
+    return (
+      this.#map.get(feature) ?? this.#detectRuntimeFeature(feature)
+    )
+  }
+
+  /**
+   * @param {Feature} feature
+   * @param {boolean} value
+   */
+  set (feature, value) {
+    if (features.includes(feature) === false) {
+      throw new TypeError(`unknown feature: ${feature}`)
+    }
+    this.#map.set(feature, value)
+  }
+
+  /**
+   * @param {Feature} feature
+   * @returns {boolean}
+   */
+  #detectRuntimeFeature (feature) {
+    const result = detectRuntimeFeature(feature)
+    this.#map.set(feature, result)
+    return result
+  }
+}
+
+const instance = new RuntimeFeatures()
+
+module.exports.runtimeFeatures = instance
+module.exports.default = instance
diff --git a/vanilla/node_modules/undici/lib/util/stats.js b/vanilla/node_modules/undici/lib/util/stats.js
new file mode 100644
index 0000000..a13132e
--- /dev/null
+++ b/vanilla/node_modules/undici/lib/util/stats.js
@@ -0,0 +1,32 @@
+'use strict'
+
+const {
+  kConnected,
+  kPending,
+  kRunning,
+  kSize,
+  kFree,
+  kQueued
+} = require('../core/symbols')
+
+class ClientStats {
+  constructor (client) {
+    this.connected = client[kConnected]
+    this.pending = client[kPending]
+    this.running = client[kRunning]
+    this.size = client[kSize]
+  }
+}
+
+class PoolStats {
+  constructor (pool) {
+    this.connected = pool[kConnected]
+    this.free = pool[kFree]
+    this.pending = pool[kPending]
+    this.queued = pool[kQueued]
+    this.running = pool[kRunning]
+    this.size = pool[kSize]
+  }
+}
+
+module.exports = { ClientStats, PoolStats }
diff --git a/vanilla/node_modules/undici/lib/util/timers.js b/vanilla/node_modules/undici/lib/util/timers.js
new file mode 100644
index 0000000..14984d4
--- /dev/null
+++ b/vanilla/node_modules/undici/lib/util/timers.js
@@ -0,0 +1,425 @@
+'use strict'
+
+/**
+ * This module offers an optimized timer implementation designed for scenarios
+ * where high precision is not critical.
+ *
+ * The timer achieves faster performance by using a low-resolution approach,
+ * with an accuracy target of within 500ms. This makes it particularly useful
+ * for timers with delays of 1 second or more, where exact timing is less
+ * crucial.
+ *
+ * It's important to note that Node.js timers are inherently imprecise, as
+ * delays can occur due to the event loop being blocked by other operations.
+ * Consequently, timers may trigger later than their scheduled time.
+ */
+
+/**
+ * The fastNow variable contains the internal fast timer clock value.
+ *
+ * @type {number}
+ */
+let fastNow = 0
+
+/**
+ * RESOLUTION_MS represents the target resolution time in milliseconds.
+ *
+ * @type {number}
+ * @default 1000
+ */
+const RESOLUTION_MS = 1e3
+
+/**
+ * TICK_MS defines the desired interval in milliseconds between each tick.
+ * The target value is set to half the resolution time, minus 1 ms, to account
+ * for potential event loop overhead.
+ *
+ * @type {number}
+ * @default 499
+ */
+const TICK_MS = (RESOLUTION_MS >> 1) - 1
+
+/**
+ * fastNowTimeout is a Node.js timer used to manage and process
+ * the FastTimers stored in the `fastTimers` array.
+ *
+ * @type {NodeJS.Timeout}
+ */
+let fastNowTimeout
+
+/**
+ * The kFastTimer symbol is used to identify FastTimer instances.
+ *
+ * @type {Symbol}
+ */
+const kFastTimer = Symbol('kFastTimer')
+
+/**
+ * The fastTimers array contains all active FastTimers.
+ *
+ * @type {FastTimer[]}
+ */
+const fastTimers = []
+
+/**
+ * These constants represent the various states of a FastTimer.
+ */
+
+/**
+ * The `NOT_IN_LIST` constant indicates that the FastTimer is not included
+ * in the `fastTimers` array. Timers with this status will not be processed
+ * during the next tick by the `onTick` function.
+ *
+ * A FastTimer can be re-added to the `fastTimers` array by invoking the
+ * `refresh` method on the FastTimer instance.
+ *
+ * @type {-2}
+ */
+const NOT_IN_LIST = -2
+
+/**
+ * The `TO_BE_CLEARED` constant indicates that the FastTimer is scheduled
+ * for removal from the `fastTimers` array. A FastTimer in this state will
+ * be removed in the next tick by the `onTick` function and will no longer
+ * be processed.
+ *
+ * This status is also set when the `clear` method is called on the FastTimer instance.
+ *
+ * @type {-1}
+ */
+const TO_BE_CLEARED = -1
+
+/**
+ * The `PENDING` constant signifies that the FastTimer is awaiting processing
+ * in the next tick by the `onTick` function. Timers with this status will have
+ * their `_idleStart` value set and their status updated to `ACTIVE` in the next tick.
+ *
+ * @type {0}
+ */
+const PENDING = 0
+
+/**
+ * The `ACTIVE` constant indicates that the FastTimer is active and waiting
+ * for its timer to expire. During the next tick, the `onTick` function will
+ * check if the timer has expired, and if so, it will execute the associated callback.
+ *
+ * @type {1}
+ */
+const ACTIVE = 1
+
+/**
+ * The onTick function processes the fastTimers array.
+ *
+ * @returns {void}
+ */
+function onTick () {
+  /**
+   * Increment the fastNow value by the TICK_MS value, despite the actual time
+   * that has passed since the last tick. This approach ensures independence
+   * from the system clock and delays caused by a blocked event loop.
+   *
+   * @type {number}
+   */
+  fastNow += TICK_MS
+
+  /**
+   * The `idx` variable is used to iterate over the `fastTimers` array.
+   * Expired timers are removed by replacing them with the last element in the array.
+   * Consequently, `idx` is only incremented when the current element is not removed.
+   *
+   * @type {number}
+   */
+  let idx = 0
+
+  /**
+   * The len variable will contain the length of the fastTimers array
+   * and will be decremented when a FastTimer should be removed from the
+   * fastTimers array.
+   *
+   * @type {number}
+   */
+  let len = fastTimers.length
+
+  while (idx < len) {
+    /**
+     * @type {FastTimer}
+     */
+    const timer = fastTimers[idx]
+
+    // If the timer is in the ACTIVE state and the timer has expired, it will
+    // be processed in the next tick.
+    if (timer._state === PENDING) {
+      // Set the _idleStart value to the fastNow value minus the TICK_MS value
+      // to account for the time the timer was in the PENDING state.
+      timer._idleStart = fastNow - TICK_MS
+      timer._state = ACTIVE
+    } else if (
+      timer._state === ACTIVE &&
+      fastNow >= timer._idleStart + timer._idleTimeout
+    ) {
+      timer._state = TO_BE_CLEARED
+      timer._idleStart = -1
+      timer._onTimeout(timer._timerArg)
+    }
+
+    if (timer._state === TO_BE_CLEARED) {
+      timer._state = NOT_IN_LIST
+
+      // Move the last element to the current index and decrement len if it is
+      // not the only element in the array.
+      if (--len !== 0) {
+        fastTimers[idx] = fastTimers[len]
+      }
+    } else {
+      ++idx
+    }
+  }
+
+  // Set the length of the fastTimers array to the new length and thus
+  // removing the excess FastTimers elements from the array.
+  fastTimers.length = len
+
+  // If there are still active FastTimers in the array, refresh the Timer.
+  // If there are no active FastTimers, the timer will be refreshed again
+  // when a new FastTimer is instantiated.
+  if (fastTimers.length !== 0) {
+    refreshTimeout()
+  }
+}
+
+function refreshTimeout () {
+  // If the fastNowTimeout is already set and the Timer has the refresh()-
+  // method available, call it to refresh the timer.
+  // Some timer objects returned by setTimeout may not have a .refresh()
+  // method (e.g. mocked timers in tests).
+  if (fastNowTimeout?.refresh) {
+    fastNowTimeout.refresh()
+    // fastNowTimeout is not instantiated yet or refresh is not availabe,
+    // create a new Timer.
+  } else {
+    clearTimeout(fastNowTimeout)
+    fastNowTimeout = setTimeout(onTick, TICK_MS)
+    // If the Timer has an unref method, call it to allow the process to exit,
+    // if there are no other active handles. When using fake timers or mocked
+    // environments (like Jest), .unref() may not be defined,
+    fastNowTimeout?.unref()
+  }
+}
+
+/**
+ * The `FastTimer` class is a data structure designed to store and manage
+ * timer information.
+ */
+class FastTimer {
+  [kFastTimer] = true
+
+  /**
+   * The state of the timer, which can be one of the following:
+   * - NOT_IN_LIST (-2)
+   * - TO_BE_CLEARED (-1)
+   * - PENDING (0)
+   * - ACTIVE (1)
+   *
+   * @type {-2|-1|0|1}
+   * @private
+   */
+  _state = NOT_IN_LIST
+
+  /**
+   * The number of milliseconds to wait before calling the callback.
+   *
+   * @type {number}
+   * @private
+   */
+  _idleTimeout = -1
+
+  /**
+   * The time in milliseconds when the timer was started. This value is used to
+   * calculate when the timer should expire.
+   *
+   * @type {number}
+   * @default -1
+   * @private
+   */
+  _idleStart = -1
+
+  /**
+   * The function to be executed when the timer expires.
+   * @type {Function}
+   * @private
+   */
+  _onTimeout
+
+  /**
+   * The argument to be passed to the callback when the timer expires.
+   *
+   * @type {*}
+   * @private
+   */
+  _timerArg
+
+  /**
+   * @constructor
+   * @param {Function} callback A function to be executed after the timer
+   * expires.
+   * @param {number} delay The time, in milliseconds that the timer should wait
+   * before the specified function or code is executed.
+   * @param {*} arg
+   */
+  constructor (callback, delay, arg) {
+    this._onTimeout = callback
+    this._idleTimeout = delay
+    this._timerArg = arg
+
+    this.refresh()
+  }
+
+  /**
+   * Sets the timer's start time to the current time, and reschedules the timer
+   * to call its callback at the previously specified duration adjusted to the
+   * current time.
+   * Using this on a timer that has already called its callback will reactivate
+   * the timer.
+   *
+   * @returns {void}
+   */
+  refresh () {
+    // In the special case that the timer is not in the list of active timers,
+    // add it back to the array to be processed in the next tick by the onTick
+    // function.
+    if (this._state === NOT_IN_LIST) {
+      fastTimers.push(this)
+    }
+
+    // If the timer is the only active timer, refresh the fastNowTimeout for
+    // better resolution.
+    if (!fastNowTimeout || fastTimers.length === 1) {
+      refreshTimeout()
+    }
+
+    // Setting the state to PENDING will cause the timer to be reset in the
+    // next tick by the onTick function.
+    this._state = PENDING
+  }
+
+  /**
+   * The `clear` method cancels the timer, preventing it from executing.
+   *
+   * @returns {void}
+   * @private
+   */
+  clear () {
+    // Set the state to TO_BE_CLEARED to mark the timer for removal in the next
+    // tick by the onTick function.
+    this._state = TO_BE_CLEARED
+
+    // Reset the _idleStart value to -1 to indicate that the timer is no longer
+    // active.
+    this._idleStart = -1
+  }
+}
+
+/**
+ * This module exports a setTimeout and clearTimeout function that can be
+ * used as a drop-in replacement for the native functions.
+ */
+module.exports = {
+  /**
+   * The setTimeout() method sets a timer which executes a function once the
+   * timer expires.
+   * @param {Function} callback A function to be executed after the timer
+   * expires.
+   * @param {number} delay The time, in milliseconds that the timer should
+   * wait before the specified function or code is executed.
+   * @param {*} [arg] An optional argument to be passed to the callback function
+   * when the timer expires.
+   * @returns {NodeJS.Timeout|FastTimer}
+   */
+  setTimeout (callback, delay, arg) {
+    // If the delay is less than or equal to the RESOLUTION_MS value return a
+    // native Node.js Timer instance.
+    return delay <= RESOLUTION_MS
+      ? setTimeout(callback, delay, arg)
+      : new FastTimer(callback, delay, arg)
+  },
+  /**
+   * The clearTimeout method cancels an instantiated Timer previously created
+   * by calling setTimeout.
+   *
+   * @param {NodeJS.Timeout|FastTimer} timeout
+   */
+  clearTimeout (timeout) {
+    // If the timeout is a FastTimer, call its own clear method.
+    if (timeout[kFastTimer]) {
+      /**
+       * @type {FastTimer}
+       */
+      timeout.clear()
+      // Otherwise it is an instance of a native NodeJS.Timeout, so call the
+      // Node.js native clearTimeout function.
+    } else {
+      clearTimeout(timeout)
+    }
+  },
+  /**
+   * The setFastTimeout() method sets a fastTimer which executes a function once
+   * the timer expires.
+   * @param {Function} callback A function to be executed after the timer
+   * expires.
+   * @param {number} delay The time, in milliseconds that the timer should
+   * wait before the specified function or code is executed.
+   * @param {*} [arg] An optional argument to be passed to the callback function
+   * when the timer expires.
+   * @returns {FastTimer}
+   */
+  setFastTimeout (callback, delay, arg) {
+    return new FastTimer(callback, delay, arg)
+  },
+  /**
+   * The clearTimeout method cancels an instantiated FastTimer previously
+   * created by calling setFastTimeout.
+   *
+   * @param {FastTimer} timeout
+   */
+  clearFastTimeout (timeout) {
+    timeout.clear()
+  },
+  /**
+   * The now method returns the value of the internal fast timer clock.
+   *
+   * @returns {number}
+   */
+  now () {
+    return fastNow
+  },
+  /**
+   * Trigger the onTick function to process the fastTimers array.
+   * Exported for testing purposes only.
+   * Marking as deprecated to discourage any use outside of testing.
+   * @deprecated
+   * @param {number} [delay=0] The delay in milliseconds to add to the now value.
+   */
+  tick (delay = 0) {
+    fastNow += delay - RESOLUTION_MS + 1
+    onTick()
+    onTick()
+  },
+  /**
+   * Reset FastTimers.
+   * Exported for testing purposes only.
+   * Marking as deprecated to discourage any use outside of testing.
+   * @deprecated
+   */
+  reset () {
+    fastNow = 0
+    fastTimers.length = 0
+    clearTimeout(fastNowTimeout)
+    fastNowTimeout = null
+  },
+  /**
+   * Exporting for testing purposes only.
+   * Marking as deprecated to discourage any use outside of testing.
+   * @deprecated
+   */
+  kFastTimer
+}