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

12 files changed, 2507 insertions, 0 deletions

diff --git a/vanilla/node_modules/undici/lib/mock/mock-agent.js b/vanilla/node_modules/undici/lib/mock/mock-agent.js
new file mode 100644
index 0000000..61449e0
--- /dev/null
+++ b/vanilla/node_modules/undici/lib/mock/mock-agent.js
@@ -0,0 +1,232 @@
+'use strict'
+
+const { kClients } = require('../core/symbols')
+const Agent = require('../dispatcher/agent')
+const {
+  kAgent,
+  kMockAgentSet,
+  kMockAgentGet,
+  kDispatches,
+  kIsMockActive,
+  kNetConnect,
+  kGetNetConnect,
+  kOptions,
+  kFactory,
+  kMockAgentRegisterCallHistory,
+  kMockAgentIsCallHistoryEnabled,
+  kMockAgentAddCallHistoryLog,
+  kMockAgentMockCallHistoryInstance,
+  kMockAgentAcceptsNonStandardSearchParameters,
+  kMockCallHistoryAddLog,
+  kIgnoreTrailingSlash
+} = require('./mock-symbols')
+const MockClient = require('./mock-client')
+const MockPool = require('./mock-pool')
+const { matchValue, normalizeSearchParams, buildAndValidateMockOptions, normalizeOrigin } = require('./mock-utils')
+const { InvalidArgumentError, UndiciError } = require('../core/errors')
+const Dispatcher = require('../dispatcher/dispatcher')
+const PendingInterceptorsFormatter = require('./pending-interceptors-formatter')
+const { MockCallHistory } = require('./mock-call-history')
+
+class MockAgent extends Dispatcher {
+  constructor (opts = {}) {
+    super(opts)
+
+    const mockOptions = buildAndValidateMockOptions(opts)
+
+    this[kNetConnect] = true
+    this[kIsMockActive] = true
+    this[kMockAgentIsCallHistoryEnabled] = mockOptions.enableCallHistory ?? false
+    this[kMockAgentAcceptsNonStandardSearchParameters] = mockOptions.acceptNonStandardSearchParameters ?? false
+    this[kIgnoreTrailingSlash] = mockOptions.ignoreTrailingSlash ?? false
+
+    // Instantiate Agent and encapsulate
+    if (opts?.agent && typeof opts.agent.dispatch !== 'function') {
+      throw new InvalidArgumentError('Argument opts.agent must implement Agent')
+    }
+    const agent = opts?.agent ? opts.agent : new Agent(opts)
+    this[kAgent] = agent
+
+    this[kClients] = agent[kClients]
+    this[kOptions] = mockOptions
+
+    if (this[kMockAgentIsCallHistoryEnabled]) {
+      this[kMockAgentRegisterCallHistory]()
+    }
+  }
+
+  get (origin) {
+    // Normalize origin to handle URL objects and case-insensitive hostnames
+    const normalizedOrigin = normalizeOrigin(origin)
+    const originKey = this[kIgnoreTrailingSlash] ? normalizedOrigin.replace(/\/$/, '') : normalizedOrigin
+
+    let dispatcher = this[kMockAgentGet](originKey)
+
+    if (!dispatcher) {
+      dispatcher = this[kFactory](originKey)
+      this[kMockAgentSet](originKey, dispatcher)
+    }
+    return dispatcher
+  }
+
+  dispatch (opts, handler) {
+    opts.origin = normalizeOrigin(opts.origin)
+
+    // Call MockAgent.get to perform additional setup before dispatching as normal
+    this.get(opts.origin)
+
+    this[kMockAgentAddCallHistoryLog](opts)
+
+    const acceptNonStandardSearchParameters = this[kMockAgentAcceptsNonStandardSearchParameters]
+
+    const dispatchOpts = { ...opts }
+
+    if (acceptNonStandardSearchParameters && dispatchOpts.path) {
+      const [path, searchParams] = dispatchOpts.path.split('?')
+      const normalizedSearchParams = normalizeSearchParams(searchParams, acceptNonStandardSearchParameters)
+      dispatchOpts.path = `${path}?${normalizedSearchParams}`
+    }
+
+    return this[kAgent].dispatch(dispatchOpts, handler)
+  }
+
+  async close () {
+    this.clearCallHistory()
+    await this[kAgent].close()
+    this[kClients].clear()
+  }
+
+  deactivate () {
+    this[kIsMockActive] = false
+  }
+
+  activate () {
+    this[kIsMockActive] = true
+  }
+
+  enableNetConnect (matcher) {
+    if (typeof matcher === 'string' || typeof matcher === 'function' || matcher instanceof RegExp) {
+      if (Array.isArray(this[kNetConnect])) {
+        this[kNetConnect].push(matcher)
+      } else {
+        this[kNetConnect] = [matcher]
+      }
+    } else if (typeof matcher === 'undefined') {
+      this[kNetConnect] = true
+    } else {
+      throw new InvalidArgumentError('Unsupported matcher. Must be one of String|Function|RegExp.')
+    }
+  }
+
+  disableNetConnect () {
+    this[kNetConnect] = false
+  }
+
+  enableCallHistory () {
+    this[kMockAgentIsCallHistoryEnabled] = true
+
+    return this
+  }
+
+  disableCallHistory () {
+    this[kMockAgentIsCallHistoryEnabled] = false
+
+    return this
+  }
+
+  getCallHistory () {
+    return this[kMockAgentMockCallHistoryInstance]
+  }
+
+  clearCallHistory () {
+    if (this[kMockAgentMockCallHistoryInstance] !== undefined) {
+      this[kMockAgentMockCallHistoryInstance].clear()
+    }
+  }
+
+  // This is required to bypass issues caused by using global symbols - see:
+  // https://github.com/nodejs/undici/issues/1447
+  get isMockActive () {
+    return this[kIsMockActive]
+  }
+
+  [kMockAgentRegisterCallHistory] () {
+    if (this[kMockAgentMockCallHistoryInstance] === undefined) {
+      this[kMockAgentMockCallHistoryInstance] = new MockCallHistory()
+    }
+  }
+
+  [kMockAgentAddCallHistoryLog] (opts) {
+    if (this[kMockAgentIsCallHistoryEnabled]) {
+      // additional setup when enableCallHistory class method is used after mockAgent instantiation
+      this[kMockAgentRegisterCallHistory]()
+
+      // add call history log on every call (intercepted or not)
+      this[kMockAgentMockCallHistoryInstance][kMockCallHistoryAddLog](opts)
+    }
+  }
+
+  [kMockAgentSet] (origin, dispatcher) {
+    this[kClients].set(origin, { count: 0, dispatcher })
+  }
+
+  [kFactory] (origin) {
+    const mockOptions = Object.assign({ agent: this }, this[kOptions])
+    return this[kOptions] && this[kOptions].connections === 1
+      ? new MockClient(origin, mockOptions)
+      : new MockPool(origin, mockOptions)
+  }
+
+  [kMockAgentGet] (origin) {
+    // First check if we can immediately find it
+    const result = this[kClients].get(origin)
+    if (result?.dispatcher) {
+      return result.dispatcher
+    }
+
+    // If the origin is not a string create a dummy parent pool and return to user
+    if (typeof origin !== 'string') {
+      const dispatcher = this[kFactory]('http://localhost:9999')
+      this[kMockAgentSet](origin, dispatcher)
+      return dispatcher
+    }
+
+    // If we match, create a pool and assign the same dispatches
+    for (const [keyMatcher, result] of Array.from(this[kClients])) {
+      if (result && typeof keyMatcher !== 'string' && matchValue(keyMatcher, origin)) {
+        const dispatcher = this[kFactory](origin)
+        this[kMockAgentSet](origin, dispatcher)
+        dispatcher[kDispatches] = result.dispatcher[kDispatches]
+        return dispatcher
+      }
+    }
+  }
+
+  [kGetNetConnect] () {
+    return this[kNetConnect]
+  }
+
+  pendingInterceptors () {
+    const mockAgentClients = this[kClients]
+
+    return Array.from(mockAgentClients.entries())
+      .flatMap(([origin, result]) => result.dispatcher[kDispatches].map(dispatch => ({ ...dispatch, origin })))
+      .filter(({ pending }) => pending)
+  }
+
+  assertNoPendingInterceptors ({ pendingInterceptorsFormatter = new PendingInterceptorsFormatter() } = {}) {
+    const pending = this.pendingInterceptors()
+
+    if (pending.length === 0) {
+      return
+    }
+
+    throw new UndiciError(
+      pending.length === 1
+        ? `1 interceptor is pending:\n\n${pendingInterceptorsFormatter.format(pending)}`.trim()
+        : `${pending.length} interceptors are pending:\n\n${pendingInterceptorsFormatter.format(pending)}`.trim()
+    )
+  }
+}
+
+module.exports = MockAgent
diff --git a/vanilla/node_modules/undici/lib/mock/mock-call-history.js b/vanilla/node_modules/undici/lib/mock/mock-call-history.js
new file mode 100644
index 0000000..d4a92b2
--- /dev/null
+++ b/vanilla/node_modules/undici/lib/mock/mock-call-history.js
@@ -0,0 +1,248 @@
+'use strict'
+
+const { kMockCallHistoryAddLog } = require('./mock-symbols')
+const { InvalidArgumentError } = require('../core/errors')
+
+function handleFilterCallsWithOptions (criteria, options, handler, store) {
+  switch (options.operator) {
+    case 'OR':
+      store.push(...handler(criteria))
+
+      return store
+    case 'AND':
+      return handler.call({ logs: store }, criteria)
+    default:
+      // guard -- should never happens because buildAndValidateFilterCallsOptions is called before
+      throw new InvalidArgumentError('options.operator must to be a case insensitive string equal to \'OR\' or \'AND\'')
+  }
+}
+
+function buildAndValidateFilterCallsOptions (options = {}) {
+  const finalOptions = {}
+
+  if ('operator' in options) {
+    if (typeof options.operator !== 'string' || (options.operator.toUpperCase() !== 'OR' && options.operator.toUpperCase() !== 'AND')) {
+      throw new InvalidArgumentError('options.operator must to be a case insensitive string equal to \'OR\' or \'AND\'')
+    }
+
+    return {
+      ...finalOptions,
+      operator: options.operator.toUpperCase()
+    }
+  }
+
+  return finalOptions
+}
+
+function makeFilterCalls (parameterName) {
+  return (parameterValue) => {
+    if (typeof parameterValue === 'string' || parameterValue == null) {
+      return this.logs.filter((log) => {
+        return log[parameterName] === parameterValue
+      })
+    }
+    if (parameterValue instanceof RegExp) {
+      return this.logs.filter((log) => {
+        return parameterValue.test(log[parameterName])
+      })
+    }
+
+    throw new InvalidArgumentError(`${parameterName} parameter should be one of string, regexp, undefined or null`)
+  }
+}
+function computeUrlWithMaybeSearchParameters (requestInit) {
+  // path can contains query url parameters
+  // or query can contains query url parameters
+  try {
+    const url = new URL(requestInit.path, requestInit.origin)
+
+    // requestInit.path contains query url parameters
+    // requestInit.query is then undefined
+    if (url.search.length !== 0) {
+      return url
+    }
+
+    // requestInit.query can be populated here
+    url.search = new URLSearchParams(requestInit.query).toString()
+
+    return url
+  } catch (error) {
+    throw new InvalidArgumentError('An error occurred when computing MockCallHistoryLog.url', { cause: error })
+  }
+}
+
+class MockCallHistoryLog {
+  constructor (requestInit = {}) {
+    this.body = requestInit.body
+    this.headers = requestInit.headers
+    this.method = requestInit.method
+
+    const url = computeUrlWithMaybeSearchParameters(requestInit)
+
+    this.fullUrl = url.toString()
+    this.origin = url.origin
+    this.path = url.pathname
+    this.searchParams = Object.fromEntries(url.searchParams)
+    this.protocol = url.protocol
+    this.host = url.host
+    this.port = url.port
+    this.hash = url.hash
+  }
+
+  toMap () {
+    return new Map([
+      ['protocol', this.protocol],
+      ['host', this.host],
+      ['port', this.port],
+      ['origin', this.origin],
+      ['path', this.path],
+      ['hash', this.hash],
+      ['searchParams', this.searchParams],
+      ['fullUrl', this.fullUrl],
+      ['method', this.method],
+      ['body', this.body],
+      ['headers', this.headers]]
+    )
+  }
+
+  toString () {
+    const options = { betweenKeyValueSeparator: '->', betweenPairSeparator: '|' }
+    let result = ''
+
+    this.toMap().forEach((value, key) => {
+      if (typeof value === 'string' || value === undefined || value === null) {
+        result = `${result}${key}${options.betweenKeyValueSeparator}${value}${options.betweenPairSeparator}`
+      }
+      if ((typeof value === 'object' && value !== null) || Array.isArray(value)) {
+        result = `${result}${key}${options.betweenKeyValueSeparator}${JSON.stringify(value)}${options.betweenPairSeparator}`
+      }
+      // maybe miss something for non Record / Array headers and searchParams here
+    })
+
+    // delete last betweenPairSeparator
+    return result.slice(0, -1)
+  }
+}
+
+class MockCallHistory {
+  logs = []
+
+  calls () {
+    return this.logs
+  }
+
+  firstCall () {
+    return this.logs.at(0)
+  }
+
+  lastCall () {
+    return this.logs.at(-1)
+  }
+
+  nthCall (number) {
+    if (typeof number !== 'number') {
+      throw new InvalidArgumentError('nthCall must be called with a number')
+    }
+    if (!Number.isInteger(number)) {
+      throw new InvalidArgumentError('nthCall must be called with an integer')
+    }
+    if (Math.sign(number) !== 1) {
+      throw new InvalidArgumentError('nthCall must be called with a positive value. use firstCall or lastCall instead')
+    }
+
+    // non zero based index. this is more human readable
+    return this.logs.at(number - 1)
+  }
+
+  filterCalls (criteria, options) {
+    // perf
+    if (this.logs.length === 0) {
+      return this.logs
+    }
+    if (typeof criteria === 'function') {
+      return this.logs.filter(criteria)
+    }
+    if (criteria instanceof RegExp) {
+      return this.logs.filter((log) => {
+        return criteria.test(log.toString())
+      })
+    }
+    if (typeof criteria === 'object' && criteria !== null) {
+      // no criteria - returning all logs
+      if (Object.keys(criteria).length === 0) {
+        return this.logs
+      }
+
+      const finalOptions = { operator: 'OR', ...buildAndValidateFilterCallsOptions(options) }
+
+      let maybeDuplicatedLogsFiltered = []
+      if ('protocol' in criteria) {
+        maybeDuplicatedLogsFiltered = handleFilterCallsWithOptions(criteria.protocol, finalOptions, this.filterCallsByProtocol, maybeDuplicatedLogsFiltered)
+      }
+      if ('host' in criteria) {
+        maybeDuplicatedLogsFiltered = handleFilterCallsWithOptions(criteria.host, finalOptions, this.filterCallsByHost, maybeDuplicatedLogsFiltered)
+      }
+      if ('port' in criteria) {
+        maybeDuplicatedLogsFiltered = handleFilterCallsWithOptions(criteria.port, finalOptions, this.filterCallsByPort, maybeDuplicatedLogsFiltered)
+      }
+      if ('origin' in criteria) {
+        maybeDuplicatedLogsFiltered = handleFilterCallsWithOptions(criteria.origin, finalOptions, this.filterCallsByOrigin, maybeDuplicatedLogsFiltered)
+      }
+      if ('path' in criteria) {
+        maybeDuplicatedLogsFiltered = handleFilterCallsWithOptions(criteria.path, finalOptions, this.filterCallsByPath, maybeDuplicatedLogsFiltered)
+      }
+      if ('hash' in criteria) {
+        maybeDuplicatedLogsFiltered = handleFilterCallsWithOptions(criteria.hash, finalOptions, this.filterCallsByHash, maybeDuplicatedLogsFiltered)
+      }
+      if ('fullUrl' in criteria) {
+        maybeDuplicatedLogsFiltered = handleFilterCallsWithOptions(criteria.fullUrl, finalOptions, this.filterCallsByFullUrl, maybeDuplicatedLogsFiltered)
+      }
+      if ('method' in criteria) {
+        maybeDuplicatedLogsFiltered = handleFilterCallsWithOptions(criteria.method, finalOptions, this.filterCallsByMethod, maybeDuplicatedLogsFiltered)
+      }
+
+      const uniqLogsFiltered = [...new Set(maybeDuplicatedLogsFiltered)]
+
+      return uniqLogsFiltered
+    }
+
+    throw new InvalidArgumentError('criteria parameter should be one of function, regexp, or object')
+  }
+
+  filterCallsByProtocol = makeFilterCalls.call(this, 'protocol')
+
+  filterCallsByHost = makeFilterCalls.call(this, 'host')
+
+  filterCallsByPort = makeFilterCalls.call(this, 'port')
+
+  filterCallsByOrigin = makeFilterCalls.call(this, 'origin')
+
+  filterCallsByPath = makeFilterCalls.call(this, 'path')
+
+  filterCallsByHash = makeFilterCalls.call(this, 'hash')
+
+  filterCallsByFullUrl = makeFilterCalls.call(this, 'fullUrl')
+
+  filterCallsByMethod = makeFilterCalls.call(this, 'method')
+
+  clear () {
+    this.logs = []
+  }
+
+  [kMockCallHistoryAddLog] (requestInit) {
+    const log = new MockCallHistoryLog(requestInit)
+
+    this.logs.push(log)
+
+    return log
+  }
+
+  * [Symbol.iterator] () {
+    for (const log of this.calls()) {
+      yield log
+    }
+  }
+}
+
+module.exports.MockCallHistory = MockCallHistory
+module.exports.MockCallHistoryLog = MockCallHistoryLog
diff --git a/vanilla/node_modules/undici/lib/mock/mock-client.js b/vanilla/node_modules/undici/lib/mock/mock-client.js
new file mode 100644
index 0000000..b3be7ab
--- /dev/null
+++ b/vanilla/node_modules/undici/lib/mock/mock-client.js
@@ -0,0 +1,68 @@
+'use strict'
+
+const { promisify } = require('node:util')
+const Client = require('../dispatcher/client')
+const { buildMockDispatch } = require('./mock-utils')
+const {
+  kDispatches,
+  kMockAgent,
+  kClose,
+  kOriginalClose,
+  kOrigin,
+  kOriginalDispatch,
+  kConnected,
+  kIgnoreTrailingSlash
+} = require('./mock-symbols')
+const { MockInterceptor } = require('./mock-interceptor')
+const Symbols = require('../core/symbols')
+const { InvalidArgumentError } = require('../core/errors')
+
+/**
+ * MockClient provides an API that extends the Client to influence the mockDispatches.
+ */
+class MockClient extends Client {
+  constructor (origin, opts) {
+    if (!opts || !opts.agent || typeof opts.agent.dispatch !== 'function') {
+      throw new InvalidArgumentError('Argument opts.agent must implement Agent')
+    }
+
+    super(origin, opts)
+
+    this[kMockAgent] = opts.agent
+    this[kOrigin] = origin
+    this[kIgnoreTrailingSlash] = opts.ignoreTrailingSlash ?? false
+    this[kDispatches] = []
+    this[kConnected] = 1
+    this[kOriginalDispatch] = this.dispatch
+    this[kOriginalClose] = this.close.bind(this)
+
+    this.dispatch = buildMockDispatch.call(this)
+    this.close = this[kClose]
+  }
+
+  get [Symbols.kConnected] () {
+    return this[kConnected]
+  }
+
+  /**
+   * Sets up the base interceptor for mocking replies from undici.
+   */
+  intercept (opts) {
+    return new MockInterceptor(
+      opts && { ignoreTrailingSlash: this[kIgnoreTrailingSlash], ...opts },
+      this[kDispatches]
+    )
+  }
+
+  cleanMocks () {
+    this[kDispatches] = []
+  }
+
+  async [kClose] () {
+    await promisify(this[kOriginalClose])()
+    this[kConnected] = 0
+    this[kMockAgent][Symbols.kClients].delete(this[kOrigin])
+  }
+}
+
+module.exports = MockClient
diff --git a/vanilla/node_modules/undici/lib/mock/mock-errors.js b/vanilla/node_modules/undici/lib/mock/mock-errors.js
new file mode 100644
index 0000000..69e4f9c
--- /dev/null
+++ b/vanilla/node_modules/undici/lib/mock/mock-errors.js
@@ -0,0 +1,29 @@
+'use strict'
+
+const { UndiciError } = require('../core/errors')
+
+const kMockNotMatchedError = Symbol.for('undici.error.UND_MOCK_ERR_MOCK_NOT_MATCHED')
+
+/**
+ * The request does not match any registered mock dispatches.
+ */
+class MockNotMatchedError extends UndiciError {
+  constructor (message) {
+    super(message)
+    this.name = 'MockNotMatchedError'
+    this.message = message || 'The request does not match any registered mock dispatches'
+    this.code = 'UND_MOCK_ERR_MOCK_NOT_MATCHED'
+  }
+
+  static [Symbol.hasInstance] (instance) {
+    return instance && instance[kMockNotMatchedError] === true
+  }
+
+  get [kMockNotMatchedError] () {
+    return true
+  }
+}
+
+module.exports = {
+  MockNotMatchedError
+}
diff --git a/vanilla/node_modules/undici/lib/mock/mock-interceptor.js b/vanilla/node_modules/undici/lib/mock/mock-interceptor.js
new file mode 100644
index 0000000..1ea7aac
--- /dev/null
+++ b/vanilla/node_modules/undici/lib/mock/mock-interceptor.js
@@ -0,0 +1,209 @@
+'use strict'
+
+const { getResponseData, buildKey, addMockDispatch } = require('./mock-utils')
+const {
+  kDispatches,
+  kDispatchKey,
+  kDefaultHeaders,
+  kDefaultTrailers,
+  kContentLength,
+  kMockDispatch,
+  kIgnoreTrailingSlash
+} = require('./mock-symbols')
+const { InvalidArgumentError } = require('../core/errors')
+const { serializePathWithQuery } = require('../core/util')
+
+/**
+ * Defines the scope API for an interceptor reply
+ */
+class MockScope {
+  constructor (mockDispatch) {
+    this[kMockDispatch] = mockDispatch
+  }
+
+  /**
+   * Delay a reply by a set amount in ms.
+   */
+  delay (waitInMs) {
+    if (typeof waitInMs !== 'number' || !Number.isInteger(waitInMs) || waitInMs <= 0) {
+      throw new InvalidArgumentError('waitInMs must be a valid integer > 0')
+    }
+
+    this[kMockDispatch].delay = waitInMs
+    return this
+  }
+
+  /**
+   * For a defined reply, never mark as consumed.
+   */
+  persist () {
+    this[kMockDispatch].persist = true
+    return this
+  }
+
+  /**
+   * Allow one to define a reply for a set amount of matching requests.
+   */
+  times (repeatTimes) {
+    if (typeof repeatTimes !== 'number' || !Number.isInteger(repeatTimes) || repeatTimes <= 0) {
+      throw new InvalidArgumentError('repeatTimes must be a valid integer > 0')
+    }
+
+    this[kMockDispatch].times = repeatTimes
+    return this
+  }
+}
+
+/**
+ * Defines an interceptor for a Mock
+ */
+class MockInterceptor {
+  constructor (opts, mockDispatches) {
+    if (typeof opts !== 'object') {
+      throw new InvalidArgumentError('opts must be an object')
+    }
+    if (typeof opts.path === 'undefined') {
+      throw new InvalidArgumentError('opts.path must be defined')
+    }
+    if (typeof opts.method === 'undefined') {
+      opts.method = 'GET'
+    }
+    // See https://github.com/nodejs/undici/issues/1245
+    // As per RFC 3986, clients are not supposed to send URI
+    // fragments to servers when they retrieve a document,
+    if (typeof opts.path === 'string') {
+      if (opts.query) {
+        opts.path = serializePathWithQuery(opts.path, opts.query)
+      } else {
+        // Matches https://github.com/nodejs/undici/blob/main/lib/web/fetch/index.js#L1811
+        const parsedURL = new URL(opts.path, 'data://')
+        opts.path = parsedURL.pathname + parsedURL.search
+      }
+    }
+    if (typeof opts.method === 'string') {
+      opts.method = opts.method.toUpperCase()
+    }
+
+    this[kDispatchKey] = buildKey(opts)
+    this[kDispatches] = mockDispatches
+    this[kIgnoreTrailingSlash] = opts.ignoreTrailingSlash ?? false
+    this[kDefaultHeaders] = {}
+    this[kDefaultTrailers] = {}
+    this[kContentLength] = false
+  }
+
+  createMockScopeDispatchData ({ statusCode, data, responseOptions }) {
+    const responseData = getResponseData(data)
+    const contentLength = this[kContentLength] ? { 'content-length': responseData.length } : {}
+    const headers = { ...this[kDefaultHeaders], ...contentLength, ...responseOptions.headers }
+    const trailers = { ...this[kDefaultTrailers], ...responseOptions.trailers }
+
+    return { statusCode, data, headers, trailers }
+  }
+
+  validateReplyParameters (replyParameters) {
+    if (typeof replyParameters.statusCode === 'undefined') {
+      throw new InvalidArgumentError('statusCode must be defined')
+    }
+    if (typeof replyParameters.responseOptions !== 'object' || replyParameters.responseOptions === null) {
+      throw new InvalidArgumentError('responseOptions must be an object')
+    }
+  }
+
+  /**
+   * Mock an undici request with a defined reply.
+   */
+  reply (replyOptionsCallbackOrStatusCode) {
+    // Values of reply aren't available right now as they
+    // can only be available when the reply callback is invoked.
+    if (typeof replyOptionsCallbackOrStatusCode === 'function') {
+      // We'll first wrap the provided callback in another function,
+      // this function will properly resolve the data from the callback
+      // when invoked.
+      const wrappedDefaultsCallback = (opts) => {
+        // Our reply options callback contains the parameter for statusCode, data and options.
+        const resolvedData = replyOptionsCallbackOrStatusCode(opts)
+
+        // Check if it is in the right format
+        if (typeof resolvedData !== 'object' || resolvedData === null) {
+          throw new InvalidArgumentError('reply options callback must return an object')
+        }
+
+        const replyParameters = { data: '', responseOptions: {}, ...resolvedData }
+        this.validateReplyParameters(replyParameters)
+        // Since the values can be obtained immediately we return them
+        // from this higher order function that will be resolved later.
+        return {
+          ...this.createMockScopeDispatchData(replyParameters)
+        }
+      }
+
+      // Add usual dispatch data, but this time set the data parameter to function that will eventually provide data.
+      const newMockDispatch = addMockDispatch(this[kDispatches], this[kDispatchKey], wrappedDefaultsCallback, { ignoreTrailingSlash: this[kIgnoreTrailingSlash] })
+      return new MockScope(newMockDispatch)
+    }
+
+    // We can have either one or three parameters, if we get here,
+    // we should have 1-3 parameters. So we spread the arguments of
+    // this function to obtain the parameters, since replyData will always
+    // just be the statusCode.
+    const replyParameters = {
+      statusCode: replyOptionsCallbackOrStatusCode,
+      data: arguments[1] === undefined ? '' : arguments[1],
+      responseOptions: arguments[2] === undefined ? {} : arguments[2]
+    }
+    this.validateReplyParameters(replyParameters)
+
+    // Send in-already provided data like usual
+    const dispatchData = this.createMockScopeDispatchData(replyParameters)
+    const newMockDispatch = addMockDispatch(this[kDispatches], this[kDispatchKey], dispatchData, { ignoreTrailingSlash: this[kIgnoreTrailingSlash] })
+    return new MockScope(newMockDispatch)
+  }
+
+  /**
+   * Mock an undici request with a defined error.
+   */
+  replyWithError (error) {
+    if (typeof error === 'undefined') {
+      throw new InvalidArgumentError('error must be defined')
+    }
+
+    const newMockDispatch = addMockDispatch(this[kDispatches], this[kDispatchKey], { error }, { ignoreTrailingSlash: this[kIgnoreTrailingSlash] })
+    return new MockScope(newMockDispatch)
+  }
+
+  /**
+   * Set default reply headers on the interceptor for subsequent replies
+   */
+  defaultReplyHeaders (headers) {
+    if (typeof headers === 'undefined') {
+      throw new InvalidArgumentError('headers must be defined')
+    }
+
+    this[kDefaultHeaders] = headers
+    return this
+  }
+
+  /**
+   * Set default reply trailers on the interceptor for subsequent replies
+   */
+  defaultReplyTrailers (trailers) {
+    if (typeof trailers === 'undefined') {
+      throw new InvalidArgumentError('trailers must be defined')
+    }
+
+    this[kDefaultTrailers] = trailers
+    return this
+  }
+
+  /**
+   * Set reply content length header for replies on the interceptor
+   */
+  replyContentLength () {
+    this[kContentLength] = true
+    return this
+  }
+}
+
+module.exports.MockInterceptor = MockInterceptor
+module.exports.MockScope = MockScope
diff --git a/vanilla/node_modules/undici/lib/mock/mock-pool.js b/vanilla/node_modules/undici/lib/mock/mock-pool.js
new file mode 100644
index 0000000..2121e3c
--- /dev/null
+++ b/vanilla/node_modules/undici/lib/mock/mock-pool.js
@@ -0,0 +1,68 @@
+'use strict'
+
+const { promisify } = require('node:util')
+const Pool = require('../dispatcher/pool')
+const { buildMockDispatch } = require('./mock-utils')
+const {
+  kDispatches,
+  kMockAgent,
+  kClose,
+  kOriginalClose,
+  kOrigin,
+  kOriginalDispatch,
+  kConnected,
+  kIgnoreTrailingSlash
+} = require('./mock-symbols')
+const { MockInterceptor } = require('./mock-interceptor')
+const Symbols = require('../core/symbols')
+const { InvalidArgumentError } = require('../core/errors')
+
+/**
+ * MockPool provides an API that extends the Pool to influence the mockDispatches.
+ */
+class MockPool extends Pool {
+  constructor (origin, opts) {
+    if (!opts || !opts.agent || typeof opts.agent.dispatch !== 'function') {
+      throw new InvalidArgumentError('Argument opts.agent must implement Agent')
+    }
+
+    super(origin, opts)
+
+    this[kMockAgent] = opts.agent
+    this[kOrigin] = origin
+    this[kIgnoreTrailingSlash] = opts.ignoreTrailingSlash ?? false
+    this[kDispatches] = []
+    this[kConnected] = 1
+    this[kOriginalDispatch] = this.dispatch
+    this[kOriginalClose] = this.close.bind(this)
+
+    this.dispatch = buildMockDispatch.call(this)
+    this.close = this[kClose]
+  }
+
+  get [Symbols.kConnected] () {
+    return this[kConnected]
+  }
+
+  /**
+   * Sets up the base interceptor for mocking replies from undici.
+   */
+  intercept (opts) {
+    return new MockInterceptor(
+      opts && { ignoreTrailingSlash: this[kIgnoreTrailingSlash], ...opts },
+      this[kDispatches]
+    )
+  }
+
+  cleanMocks () {
+    this[kDispatches] = []
+  }
+
+  async [kClose] () {
+    await promisify(this[kOriginalClose])()
+    this[kConnected] = 0
+    this[kMockAgent][Symbols.kClients].delete(this[kOrigin])
+  }
+}
+
+module.exports = MockPool
diff --git a/vanilla/node_modules/undici/lib/mock/mock-symbols.js b/vanilla/node_modules/undici/lib/mock/mock-symbols.js
new file mode 100644
index 0000000..940dbe6
--- /dev/null
+++ b/vanilla/node_modules/undici/lib/mock/mock-symbols.js
@@ -0,0 +1,31 @@
+'use strict'
+
+module.exports = {
+  kAgent: Symbol('agent'),
+  kOptions: Symbol('options'),
+  kFactory: Symbol('factory'),
+  kDispatches: Symbol('dispatches'),
+  kDispatchKey: Symbol('dispatch key'),
+  kDefaultHeaders: Symbol('default headers'),
+  kDefaultTrailers: Symbol('default trailers'),
+  kContentLength: Symbol('content length'),
+  kMockAgent: Symbol('mock agent'),
+  kMockAgentSet: Symbol('mock agent set'),
+  kMockAgentGet: Symbol('mock agent get'),
+  kMockDispatch: Symbol('mock dispatch'),
+  kClose: Symbol('close'),
+  kOriginalClose: Symbol('original agent close'),
+  kOriginalDispatch: Symbol('original dispatch'),
+  kOrigin: Symbol('origin'),
+  kIsMockActive: Symbol('is mock active'),
+  kNetConnect: Symbol('net connect'),
+  kGetNetConnect: Symbol('get net connect'),
+  kConnected: Symbol('connected'),
+  kIgnoreTrailingSlash: Symbol('ignore trailing slash'),
+  kMockAgentMockCallHistoryInstance: Symbol('mock agent mock call history name'),
+  kMockAgentRegisterCallHistory: Symbol('mock agent register mock call history'),
+  kMockAgentAddCallHistoryLog: Symbol('mock agent add call history log'),
+  kMockAgentIsCallHistoryEnabled: Symbol('mock agent is call history enabled'),
+  kMockAgentAcceptsNonStandardSearchParameters: Symbol('mock agent accepts non standard search parameters'),
+  kMockCallHistoryAddLog: Symbol('mock call history add log')
+}
diff --git a/vanilla/node_modules/undici/lib/mock/mock-utils.js b/vanilla/node_modules/undici/lib/mock/mock-utils.js
new file mode 100644
index 0000000..291a857
--- /dev/null
+++ b/vanilla/node_modules/undici/lib/mock/mock-utils.js
@@ -0,0 +1,480 @@
+'use strict'
+
+const { MockNotMatchedError } = require('./mock-errors')
+const {
+  kDispatches,
+  kMockAgent,
+  kOriginalDispatch,
+  kOrigin,
+  kGetNetConnect
+} = require('./mock-symbols')
+const { serializePathWithQuery } = require('../core/util')
+const { STATUS_CODES } = require('node:http')
+const {
+  types: {
+    isPromise
+  }
+} = require('node:util')
+const { InvalidArgumentError } = require('../core/errors')
+
+function matchValue (match, value) {
+  if (typeof match === 'string') {
+    return match === value
+  }
+  if (match instanceof RegExp) {
+    return match.test(value)
+  }
+  if (typeof match === 'function') {
+    return match(value) === true
+  }
+  return false
+}
+
+function lowerCaseEntries (headers) {
+  return Object.fromEntries(
+    Object.entries(headers).map(([headerName, headerValue]) => {
+      return [headerName.toLocaleLowerCase(), headerValue]
+    })
+  )
+}
+
+/**
+ * @param {import('../../index').Headers|string[]|Record<string, string>} headers
+ * @param {string} key
+ */
+function getHeaderByName (headers, key) {
+  if (Array.isArray(headers)) {
+    for (let i = 0; i < headers.length; i += 2) {
+      if (headers[i].toLocaleLowerCase() === key.toLocaleLowerCase()) {
+        return headers[i + 1]
+      }
+    }
+
+    return undefined
+  } else if (typeof headers.get === 'function') {
+    return headers.get(key)
+  } else {
+    return lowerCaseEntries(headers)[key.toLocaleLowerCase()]
+  }
+}
+
+/** @param {string[]} headers */
+function buildHeadersFromArray (headers) { // fetch HeadersList
+  const clone = headers.slice()
+  const entries = []
+  for (let index = 0; index < clone.length; index += 2) {
+    entries.push([clone[index], clone[index + 1]])
+  }
+  return Object.fromEntries(entries)
+}
+
+function matchHeaders (mockDispatch, headers) {
+  if (typeof mockDispatch.headers === 'function') {
+    if (Array.isArray(headers)) { // fetch HeadersList
+      headers = buildHeadersFromArray(headers)
+    }
+    return mockDispatch.headers(headers ? lowerCaseEntries(headers) : {})
+  }
+  if (typeof mockDispatch.headers === 'undefined') {
+    return true
+  }
+  if (typeof headers !== 'object' || typeof mockDispatch.headers !== 'object') {
+    return false
+  }
+
+  for (const [matchHeaderName, matchHeaderValue] of Object.entries(mockDispatch.headers)) {
+    const headerValue = getHeaderByName(headers, matchHeaderName)
+
+    if (!matchValue(matchHeaderValue, headerValue)) {
+      return false
+    }
+  }
+  return true
+}
+
+function normalizeSearchParams (query) {
+  if (typeof query !== 'string') {
+    return query
+  }
+
+  const originalQp = new URLSearchParams(query)
+  const normalizedQp = new URLSearchParams()
+
+  for (let [key, value] of originalQp.entries()) {
+    key = key.replace('[]', '')
+
+    const valueRepresentsString = /^(['"]).*\1$/.test(value)
+    if (valueRepresentsString) {
+      normalizedQp.append(key, value)
+      continue
+    }
+
+    if (value.includes(',')) {
+      const values = value.split(',')
+      for (const v of values) {
+        normalizedQp.append(key, v)
+      }
+      continue
+    }
+
+    normalizedQp.append(key, value)
+  }
+
+  return normalizedQp
+}
+
+function safeUrl (path) {
+  if (typeof path !== 'string') {
+    return path
+  }
+  const pathSegments = path.split('?', 3)
+  if (pathSegments.length !== 2) {
+    return path
+  }
+
+  const qp = new URLSearchParams(pathSegments.pop())
+  qp.sort()
+  return [...pathSegments, qp.toString()].join('?')
+}
+
+function matchKey (mockDispatch, { path, method, body, headers }) {
+  const pathMatch = matchValue(mockDispatch.path, path)
+  const methodMatch = matchValue(mockDispatch.method, method)
+  const bodyMatch = typeof mockDispatch.body !== 'undefined' ? matchValue(mockDispatch.body, body) : true
+  const headersMatch = matchHeaders(mockDispatch, headers)
+  return pathMatch && methodMatch && bodyMatch && headersMatch
+}
+
+function getResponseData (data) {
+  if (Buffer.isBuffer(data)) {
+    return data
+  } else if (data instanceof Uint8Array) {
+    return data
+  } else if (data instanceof ArrayBuffer) {
+    return data
+  } else if (typeof data === 'object') {
+    return JSON.stringify(data)
+  } else if (data) {
+    return data.toString()
+  } else {
+    return ''
+  }
+}
+
+function getMockDispatch (mockDispatches, key) {
+  const basePath = key.query ? serializePathWithQuery(key.path, key.query) : key.path
+  const resolvedPath = typeof basePath === 'string' ? safeUrl(basePath) : basePath
+
+  const resolvedPathWithoutTrailingSlash = removeTrailingSlash(resolvedPath)
+
+  // Match path
+  let matchedMockDispatches = mockDispatches
+    .filter(({ consumed }) => !consumed)
+    .filter(({ path, ignoreTrailingSlash }) => {
+      return ignoreTrailingSlash
+        ? matchValue(removeTrailingSlash(safeUrl(path)), resolvedPathWithoutTrailingSlash)
+        : matchValue(safeUrl(path), resolvedPath)
+    })
+  if (matchedMockDispatches.length === 0) {
+    throw new MockNotMatchedError(`Mock dispatch not matched for path '${resolvedPath}'`)
+  }
+
+  // Match method
+  matchedMockDispatches = matchedMockDispatches.filter(({ method }) => matchValue(method, key.method))
+  if (matchedMockDispatches.length === 0) {
+    throw new MockNotMatchedError(`Mock dispatch not matched for method '${key.method}' on path '${resolvedPath}'`)
+  }
+
+  // Match body
+  matchedMockDispatches = matchedMockDispatches.filter(({ body }) => typeof body !== 'undefined' ? matchValue(body, key.body) : true)
+  if (matchedMockDispatches.length === 0) {
+    throw new MockNotMatchedError(`Mock dispatch not matched for body '${key.body}' on path '${resolvedPath}'`)
+  }
+
+  // Match headers
+  matchedMockDispatches = matchedMockDispatches.filter((mockDispatch) => matchHeaders(mockDispatch, key.headers))
+  if (matchedMockDispatches.length === 0) {
+    const headers = typeof key.headers === 'object' ? JSON.stringify(key.headers) : key.headers
+    throw new MockNotMatchedError(`Mock dispatch not matched for headers '${headers}' on path '${resolvedPath}'`)
+  }
+
+  return matchedMockDispatches[0]
+}
+
+function addMockDispatch (mockDispatches, key, data, opts) {
+  const baseData = { timesInvoked: 0, times: 1, persist: false, consumed: false, ...opts }
+  const replyData = typeof data === 'function' ? { callback: data } : { ...data }
+  const newMockDispatch = { ...baseData, ...key, pending: true, data: { error: null, ...replyData } }
+  mockDispatches.push(newMockDispatch)
+  return newMockDispatch
+}
+
+function deleteMockDispatch (mockDispatches, key) {
+  const index = mockDispatches.findIndex(dispatch => {
+    if (!dispatch.consumed) {
+      return false
+    }
+    return matchKey(dispatch, key)
+  })
+  if (index !== -1) {
+    mockDispatches.splice(index, 1)
+  }
+}
+
+/**
+ * @param {string} path Path to remove trailing slash from
+ */
+function removeTrailingSlash (path) {
+  while (path.endsWith('/')) {
+    path = path.slice(0, -1)
+  }
+
+  if (path.length === 0) {
+    path = '/'
+  }
+
+  return path
+}
+
+function buildKey (opts) {
+  const { path, method, body, headers, query } = opts
+
+  return {
+    path,
+    method,
+    body,
+    headers,
+    query
+  }
+}
+
+function generateKeyValues (data) {
+  const keys = Object.keys(data)
+  const result = []
+  for (let i = 0; i < keys.length; ++i) {
+    const key = keys[i]
+    const value = data[key]
+    const name = Buffer.from(`${key}`)
+    if (Array.isArray(value)) {
+      for (let j = 0; j < value.length; ++j) {
+        result.push(name, Buffer.from(`${value[j]}`))
+      }
+    } else {
+      result.push(name, Buffer.from(`${value}`))
+    }
+  }
+  return result
+}
+
+/**
+ * @see https://developer.mozilla.org/en-US/docs/Web/HTTP/Status
+ * @param {number} statusCode
+ */
+function getStatusText (statusCode) {
+  return STATUS_CODES[statusCode] || 'unknown'
+}
+
+async function getResponse (body) {
+  const buffers = []
+  for await (const data of body) {
+    buffers.push(data)
+  }
+  return Buffer.concat(buffers).toString('utf8')
+}
+
+/**
+ * Mock dispatch function used to simulate undici dispatches
+ */
+function mockDispatch (opts, handler) {
+  // Get mock dispatch from built key
+  const key = buildKey(opts)
+  const mockDispatch = getMockDispatch(this[kDispatches], key)
+
+  mockDispatch.timesInvoked++
+
+  // Here's where we resolve a callback if a callback is present for the dispatch data.
+  if (mockDispatch.data.callback) {
+    mockDispatch.data = { ...mockDispatch.data, ...mockDispatch.data.callback(opts) }
+  }
+
+  // Parse mockDispatch data
+  const { data: { statusCode, data, headers, trailers, error }, delay, persist } = mockDispatch
+  const { timesInvoked, times } = mockDispatch
+
+  // If it's used up and not persistent, mark as consumed
+  mockDispatch.consumed = !persist && timesInvoked >= times
+  mockDispatch.pending = timesInvoked < times
+
+  // If specified, trigger dispatch error
+  if (error !== null) {
+    deleteMockDispatch(this[kDispatches], key)
+    handler.onError(error)
+    return true
+  }
+
+  // Track whether the request has been aborted
+  let aborted = false
+  let timer = null
+
+  function abort (err) {
+    if (aborted) {
+      return
+    }
+    aborted = true
+
+    // Clear the pending delayed response if any
+    if (timer !== null) {
+      clearTimeout(timer)
+      timer = null
+    }
+
+    // Notify the handler of the abort
+    handler.onError(err)
+  }
+
+  // Call onConnect to allow the handler to register the abort callback
+  handler.onConnect?.(abort, null)
+
+  // Handle the request with a delay if necessary
+  if (typeof delay === 'number' && delay > 0) {
+    timer = setTimeout(() => {
+      timer = null
+      handleReply(this[kDispatches])
+    }, delay)
+  } else {
+    handleReply(this[kDispatches])
+  }
+
+  function handleReply (mockDispatches, _data = data) {
+    // Don't send response if the request was aborted
+    if (aborted) {
+      return
+    }
+
+    // fetch's HeadersList is a 1D string array
+    const optsHeaders = Array.isArray(opts.headers)
+      ? buildHeadersFromArray(opts.headers)
+      : opts.headers
+    const body = typeof _data === 'function'
+      ? _data({ ...opts, headers: optsHeaders })
+      : _data
+
+    // util.types.isPromise is likely needed for jest.
+    if (isPromise(body)) {
+      // If handleReply is asynchronous, throwing an error
+      // in the callback will reject the promise, rather than
+      // synchronously throw the error, which breaks some tests.
+      // Rather, we wait for the callback to resolve if it is a
+      // promise, and then re-run handleReply with the new body.
+      return body.then((newData) => handleReply(mockDispatches, newData))
+    }
+
+    // Check again if aborted after async body resolution
+    if (aborted) {
+      return
+    }
+
+    const responseData = getResponseData(body)
+    const responseHeaders = generateKeyValues(headers)
+    const responseTrailers = generateKeyValues(trailers)
+
+    handler.onHeaders?.(statusCode, responseHeaders, resume, getStatusText(statusCode))
+    handler.onData?.(Buffer.from(responseData))
+    handler.onComplete?.(responseTrailers)
+    deleteMockDispatch(mockDispatches, key)
+  }
+
+  function resume () {}
+
+  return true
+}
+
+function buildMockDispatch () {
+  const agent = this[kMockAgent]
+  const origin = this[kOrigin]
+  const originalDispatch = this[kOriginalDispatch]
+
+  return function dispatch (opts, handler) {
+    if (agent.isMockActive) {
+      try {
+        mockDispatch.call(this, opts, handler)
+      } catch (error) {
+        if (error.code === 'UND_MOCK_ERR_MOCK_NOT_MATCHED') {
+          const netConnect = agent[kGetNetConnect]()
+          if (netConnect === false) {
+            throw new MockNotMatchedError(`${error.message}: subsequent request to origin ${origin} was not allowed (net.connect disabled)`)
+          }
+          if (checkNetConnect(netConnect, origin)) {
+            originalDispatch.call(this, opts, handler)
+          } else {
+            throw new MockNotMatchedError(`${error.message}: subsequent request to origin ${origin} was not allowed (net.connect is not enabled for this origin)`)
+          }
+        } else {
+          throw error
+        }
+      }
+    } else {
+      originalDispatch.call(this, opts, handler)
+    }
+  }
+}
+
+function checkNetConnect (netConnect, origin) {
+  const url = new URL(origin)
+  if (netConnect === true) {
+    return true
+  } else if (Array.isArray(netConnect) && netConnect.some((matcher) => matchValue(matcher, url.host))) {
+    return true
+  }
+  return false
+}
+
+function normalizeOrigin (origin) {
+  if (typeof origin !== 'string' && !(origin instanceof URL)) {
+    return origin
+  }
+
+  if (origin instanceof URL) {
+    return origin.origin
+  }
+
+  return origin.toLowerCase()
+}
+
+function buildAndValidateMockOptions (opts) {
+  const { agent, ...mockOptions } = opts
+
+  if ('enableCallHistory' in mockOptions && typeof mockOptions.enableCallHistory !== 'boolean') {
+    throw new InvalidArgumentError('options.enableCallHistory must to be a boolean')
+  }
+
+  if ('acceptNonStandardSearchParameters' in mockOptions && typeof mockOptions.acceptNonStandardSearchParameters !== 'boolean') {
+    throw new InvalidArgumentError('options.acceptNonStandardSearchParameters must to be a boolean')
+  }
+
+  if ('ignoreTrailingSlash' in mockOptions && typeof mockOptions.ignoreTrailingSlash !== 'boolean') {
+    throw new InvalidArgumentError('options.ignoreTrailingSlash must to be a boolean')
+  }
+
+  return mockOptions
+}
+
+module.exports = {
+  getResponseData,
+  getMockDispatch,
+  addMockDispatch,
+  deleteMockDispatch,
+  buildKey,
+  generateKeyValues,
+  matchValue,
+  getResponse,
+  getStatusText,
+  mockDispatch,
+  buildMockDispatch,
+  checkNetConnect,
+  buildAndValidateMockOptions,
+  getHeaderByName,
+  buildHeadersFromArray,
+  normalizeSearchParams,
+  normalizeOrigin
+}
diff --git a/vanilla/node_modules/undici/lib/mock/pending-interceptors-formatter.js b/vanilla/node_modules/undici/lib/mock/pending-interceptors-formatter.js
new file mode 100644
index 0000000..ccca951
--- /dev/null
+++ b/vanilla/node_modules/undici/lib/mock/pending-interceptors-formatter.js
@@ -0,0 +1,43 @@
+'use strict'
+
+const { Transform } = require('node:stream')
+const { Console } = require('node:console')
+
+const PERSISTENT = process.versions.icu ? '✅' : 'Y '
+const NOT_PERSISTENT = process.versions.icu ? '❌' : 'N '
+
+/**
+ * Gets the output of `console.table(…)` as a string.
+ */
+module.exports = class PendingInterceptorsFormatter {
+  constructor ({ disableColors } = {}) {
+    this.transform = new Transform({
+      transform (chunk, _enc, cb) {
+        cb(null, chunk)
+      }
+    })
+
+    this.logger = new Console({
+      stdout: this.transform,
+      inspectOptions: {
+        colors: !disableColors && !process.env.CI
+      }
+    })
+  }
+
+  format (pendingInterceptors) {
+    const withPrettyHeaders = pendingInterceptors.map(
+      ({ method, path, data: { statusCode }, persist, times, timesInvoked, origin }) => ({
+        Method: method,
+        Origin: origin,
+        Path: path,
+        'Status code': statusCode,
+        Persistent: persist ? PERSISTENT : NOT_PERSISTENT,
+        Invocations: timesInvoked,
+        Remaining: persist ? Infinity : times - timesInvoked
+      }))
+
+    this.logger.table(withPrettyHeaders)
+    return this.transform.read().toString()
+  }
+}
diff --git a/vanilla/node_modules/undici/lib/mock/snapshot-agent.js b/vanilla/node_modules/undici/lib/mock/snapshot-agent.js
new file mode 100644
index 0000000..8028011
--- /dev/null
+++ b/vanilla/node_modules/undici/lib/mock/snapshot-agent.js
@@ -0,0 +1,353 @@
+'use strict'
+
+const Agent = require('../dispatcher/agent')
+const MockAgent = require('./mock-agent')
+const { SnapshotRecorder } = require('./snapshot-recorder')
+const WrapHandler = require('../handler/wrap-handler')
+const { InvalidArgumentError, UndiciError } = require('../core/errors')
+const { validateSnapshotMode } = require('./snapshot-utils')
+
+const kSnapshotRecorder = Symbol('kSnapshotRecorder')
+const kSnapshotMode = Symbol('kSnapshotMode')
+const kSnapshotPath = Symbol('kSnapshotPath')
+const kSnapshotLoaded = Symbol('kSnapshotLoaded')
+const kRealAgent = Symbol('kRealAgent')
+
+// Static flag to ensure warning is only emitted once per process
+let warningEmitted = false
+
+class SnapshotAgent extends MockAgent {
+  constructor (opts = {}) {
+    // Emit experimental warning only once
+    if (!warningEmitted) {
+      process.emitWarning(
+        'SnapshotAgent is experimental and subject to change',
+        'ExperimentalWarning'
+      )
+      warningEmitted = true
+    }
+
+    const {
+      mode = 'record',
+      snapshotPath = null,
+      ...mockAgentOpts
+    } = opts
+
+    super(mockAgentOpts)
+
+    validateSnapshotMode(mode)
+
+    // Validate snapshotPath is provided when required
+    if ((mode === 'playback' || mode === 'update') && !snapshotPath) {
+      throw new InvalidArgumentError(`snapshotPath is required when mode is '${mode}'`)
+    }
+
+    this[kSnapshotMode] = mode
+    this[kSnapshotPath] = snapshotPath
+
+    this[kSnapshotRecorder] = new SnapshotRecorder({
+      snapshotPath: this[kSnapshotPath],
+      mode: this[kSnapshotMode],
+      maxSnapshots: opts.maxSnapshots,
+      autoFlush: opts.autoFlush,
+      flushInterval: opts.flushInterval,
+      matchHeaders: opts.matchHeaders,
+      ignoreHeaders: opts.ignoreHeaders,
+      excludeHeaders: opts.excludeHeaders,
+      matchBody: opts.matchBody,
+      matchQuery: opts.matchQuery,
+      caseSensitive: opts.caseSensitive,
+      shouldRecord: opts.shouldRecord,
+      shouldPlayback: opts.shouldPlayback,
+      excludeUrls: opts.excludeUrls
+    })
+    this[kSnapshotLoaded] = false
+
+    // For recording/update mode, we need a real agent to make actual requests
+    // For playback mode, we need a real agent if there are excluded URLs
+    if (this[kSnapshotMode] === 'record' || this[kSnapshotMode] === 'update' ||
+        (this[kSnapshotMode] === 'playback' && opts.excludeUrls && opts.excludeUrls.length > 0)) {
+      this[kRealAgent] = new Agent(opts)
+    }
+
+    // Auto-load snapshots in playback/update mode
+    if ((this[kSnapshotMode] === 'playback' || this[kSnapshotMode] === 'update') && this[kSnapshotPath]) {
+      this.loadSnapshots().catch(() => {
+        // Ignore load errors - file might not exist yet
+      })
+    }
+  }
+
+  dispatch (opts, handler) {
+    handler = WrapHandler.wrap(handler)
+    const mode = this[kSnapshotMode]
+
+    // Check if URL should be excluded (pass through without mocking/recording)
+    if (this[kSnapshotRecorder].isUrlExcluded(opts)) {
+      // Real agent is guaranteed by constructor when excludeUrls is configured
+      return this[kRealAgent].dispatch(opts, handler)
+    }
+
+    if (mode === 'playback' || mode === 'update') {
+      // Ensure snapshots are loaded
+      if (!this[kSnapshotLoaded]) {
+        // Need to load asynchronously, delegate to async version
+        return this.#asyncDispatch(opts, handler)
+      }
+
+      // Try to find existing snapshot (synchronous)
+      const snapshot = this[kSnapshotRecorder].findSnapshot(opts)
+
+      if (snapshot) {
+        // Use recorded response (synchronous)
+        return this.#replaySnapshot(snapshot, handler)
+      } else if (mode === 'update') {
+        // Make real request and record it (async required)
+        return this.#recordAndReplay(opts, handler)
+      } else {
+        // Playback mode but no snapshot found
+        const error = new UndiciError(`No snapshot found for ${opts.method || 'GET'} ${opts.path}`)
+        if (handler.onError) {
+          handler.onError(error)
+          return
+        }
+        throw error
+      }
+    } else if (mode === 'record') {
+      // Record mode - make real request and save response (async required)
+      return this.#recordAndReplay(opts, handler)
+    }
+  }
+
+  /**
+   * Async version of dispatch for when we need to load snapshots first
+   */
+  async #asyncDispatch (opts, handler) {
+    await this.loadSnapshots()
+    return this.dispatch(opts, handler)
+  }
+
+  /**
+   * Records a real request and replays the response
+   */
+  #recordAndReplay (opts, handler) {
+    const responseData = {
+      statusCode: null,
+      headers: {},
+      trailers: {},
+      body: []
+    }
+
+    const self = this // Capture 'this' context for use within nested handler callbacks
+
+    const recordingHandler = {
+      onRequestStart (controller, context) {
+        return handler.onRequestStart(controller, { ...context, history: this.history })
+      },
+
+      onRequestUpgrade (controller, statusCode, headers, socket) {
+        return handler.onRequestUpgrade(controller, statusCode, headers, socket)
+      },
+
+      onResponseStart (controller, statusCode, headers, statusMessage) {
+        responseData.statusCode = statusCode
+        responseData.headers = headers
+        return handler.onResponseStart(controller, statusCode, headers, statusMessage)
+      },
+
+      onResponseData (controller, chunk) {
+        responseData.body.push(chunk)
+        return handler.onResponseData(controller, chunk)
+      },
+
+      onResponseEnd (controller, trailers) {
+        responseData.trailers = trailers
+
+        // Record the interaction using captured 'self' context (fire and forget)
+        const responseBody = Buffer.concat(responseData.body)
+        self[kSnapshotRecorder].record(opts, {
+          statusCode: responseData.statusCode,
+          headers: responseData.headers,
+          body: responseBody,
+          trailers: responseData.trailers
+        })
+          .then(() => handler.onResponseEnd(controller, trailers))
+          .catch((error) => handler.onResponseError(controller, error))
+      }
+    }
+
+    // Use composed agent if available (includes interceptors), otherwise use real agent
+    const agent = this[kRealAgent]
+    return agent.dispatch(opts, recordingHandler)
+  }
+
+  /**
+   * Replays a recorded response
+   *
+   * @param {Object} snapshot - The recorded snapshot to replay.
+   * @param {Object} handler - The handler to call with the response data.
+   * @returns {void}
+   */
+  #replaySnapshot (snapshot, handler) {
+    try {
+      const { response } = snapshot
+
+      const controller = {
+        pause () { },
+        resume () { },
+        abort (reason) {
+          this.aborted = true
+          this.reason = reason
+        },
+
+        aborted: false,
+        paused: false
+      }
+
+      handler.onRequestStart(controller)
+
+      handler.onResponseStart(controller, response.statusCode, response.headers)
+
+      // Body is always stored as base64 string
+      const body = Buffer.from(response.body, 'base64')
+      handler.onResponseData(controller, body)
+
+      handler.onResponseEnd(controller, response.trailers)
+    } catch (error) {
+      handler.onError?.(error)
+    }
+  }
+
+  /**
+   * Loads snapshots from file
+   *
+   * @param {string} [filePath] - Optional file path to load snapshots from.
+   * @returns {Promise<void>} - Resolves when snapshots are loaded.
+   */
+  async loadSnapshots (filePath) {
+    await this[kSnapshotRecorder].loadSnapshots(filePath || this[kSnapshotPath])
+    this[kSnapshotLoaded] = true
+
+    // In playback mode, set up MockAgent interceptors for all snapshots
+    if (this[kSnapshotMode] === 'playback') {
+      this.#setupMockInterceptors()
+    }
+  }
+
+  /**
+   * Saves snapshots to file
+   *
+   * @param {string} [filePath] - Optional file path to save snapshots to.
+   * @returns {Promise<void>} - Resolves when snapshots are saved.
+   */
+  async saveSnapshots (filePath) {
+    return this[kSnapshotRecorder].saveSnapshots(filePath || this[kSnapshotPath])
+  }
+
+  /**
+   * Sets up MockAgent interceptors based on recorded snapshots.
+   *
+   * This method creates MockAgent interceptors for each recorded snapshot,
+   * allowing the SnapshotAgent to fall back to MockAgent's standard intercept
+   * mechanism in playback mode. Each interceptor is configured to persist
+   * (remain active for multiple requests) and responds with the recorded
+   * response data.
+   *
+   * Called automatically when loading snapshots in playback mode.
+   *
+   * @returns {void}
+   */
+  #setupMockInterceptors () {
+    for (const snapshot of this[kSnapshotRecorder].getSnapshots()) {
+      const { request, responses, response } = snapshot
+      const url = new URL(request.url)
+
+      const mockPool = this.get(url.origin)
+
+      // Handle both new format (responses array) and legacy format (response object)
+      const responseData = responses ? responses[0] : response
+      if (!responseData) continue
+
+      mockPool.intercept({
+        path: url.pathname + url.search,
+        method: request.method,
+        headers: request.headers,
+        body: request.body
+      }).reply(responseData.statusCode, responseData.body, {
+        headers: responseData.headers,
+        trailers: responseData.trailers
+      }).persist()
+    }
+  }
+
+  /**
+   * Gets the snapshot recorder
+   * @return {SnapshotRecorder} - The snapshot recorder instance
+   */
+  getRecorder () {
+    return this[kSnapshotRecorder]
+  }
+
+  /**
+   * Gets the current mode
+   * @return {import('./snapshot-utils').SnapshotMode} - The current snapshot mode
+   */
+  getMode () {
+    return this[kSnapshotMode]
+  }
+
+  /**
+   * Clears all snapshots
+   * @returns {void}
+   */
+  clearSnapshots () {
+    this[kSnapshotRecorder].clear()
+  }
+
+  /**
+   * Resets call counts for all snapshots (useful for test cleanup)
+   * @returns {void}
+   */
+  resetCallCounts () {
+    this[kSnapshotRecorder].resetCallCounts()
+  }
+
+  /**
+   * Deletes a specific snapshot by request options
+   * @param {import('./snapshot-recorder').SnapshotRequestOptions} requestOpts - Request options to identify the snapshot
+   * @return {Promise<boolean>} - Returns true if the snapshot was deleted, false if not found
+   */
+  deleteSnapshot (requestOpts) {
+    return this[kSnapshotRecorder].deleteSnapshot(requestOpts)
+  }
+
+  /**
+   * Gets information about a specific snapshot
+   * @returns {import('./snapshot-recorder').SnapshotInfo|null} - Snapshot information or null if not found
+   */
+  getSnapshotInfo (requestOpts) {
+    return this[kSnapshotRecorder].getSnapshotInfo(requestOpts)
+  }
+
+  /**
+   * Replaces all snapshots with new data (full replacement)
+   * @param {Array<{hash: string; snapshot: import('./snapshot-recorder').SnapshotEntryshotEntry}>|Record<string, import('./snapshot-recorder').SnapshotEntry>} snapshotData - New snapshot data to replace existing snapshots
+   * @returns {void}
+   */
+  replaceSnapshots (snapshotData) {
+    this[kSnapshotRecorder].replaceSnapshots(snapshotData)
+  }
+
+  /**
+   * Closes the agent, saving snapshots and cleaning up resources.
+   *
+   * @returns {Promise<void>}
+   */
+  async close () {
+    await this[kSnapshotRecorder].close()
+    await this[kRealAgent]?.close()
+    await super.close()
+  }
+}
+
+module.exports = SnapshotAgent
diff --git a/vanilla/node_modules/undici/lib/mock/snapshot-recorder.js b/vanilla/node_modules/undici/lib/mock/snapshot-recorder.js
new file mode 100644
index 0000000..b5d07fa
--- /dev/null
+++ b/vanilla/node_modules/undici/lib/mock/snapshot-recorder.js
@@ -0,0 +1,588 @@
+'use strict'
+
+const { writeFile, readFile, mkdir } = require('node:fs/promises')
+const { dirname, resolve } = require('node:path')
+const { setTimeout, clearTimeout } = require('node:timers')
+const { InvalidArgumentError, UndiciError } = require('../core/errors')
+const { hashId, isUrlExcludedFactory, normalizeHeaders, createHeaderFilters } = require('./snapshot-utils')
+
+/**
+ * @typedef {Object} SnapshotRequestOptions
+ * @property {string} method - HTTP method (e.g. 'GET', 'POST', etc.)
+ * @property {string} path - Request path
+ * @property {string} origin - Request origin (base URL)
+ * @property {import('./snapshot-utils').Headers|import('./snapshot-utils').UndiciHeaders} headers - Request headers
+ * @property {import('./snapshot-utils').NormalizedHeaders} _normalizedHeaders - Request headers as a lowercase object
+ * @property {string|Buffer} [body] - Request body (optional)
+ */
+
+/**
+ * @typedef {Object} SnapshotEntryRequest
+ * @property {string} method - HTTP method (e.g. 'GET', 'POST', etc.)
+ * @property {string} url - Full URL of the request
+ * @property {import('./snapshot-utils').NormalizedHeaders} headers - Normalized headers as a lowercase object
+ * @property {string|Buffer} [body] - Request body (optional)
+ */
+
+/**
+ * @typedef {Object} SnapshotEntryResponse
+ * @property {number} statusCode - HTTP status code of the response
+ * @property {import('./snapshot-utils').NormalizedHeaders} headers - Normalized response headers as a lowercase object
+ * @property {string} body - Response body as a base64url encoded string
+ * @property {Object} [trailers] - Optional response trailers
+ */
+
+/**
+ * @typedef {Object} SnapshotEntry
+ * @property {SnapshotEntryRequest} request - The request object
+ * @property {Array<SnapshotEntryResponse>} responses - Array of response objects
+ * @property {number} callCount - Number of times this snapshot has been called
+ * @property {string} timestamp - ISO timestamp of when the snapshot was created
+ */
+
+/**
+ * @typedef {Object} SnapshotRecorderMatchOptions
+ * @property {Array<string>} [matchHeaders=[]] - Headers to match (empty array means match all headers)
+ * @property {Array<string>} [ignoreHeaders=[]] - Headers to ignore for matching
+ * @property {Array<string>} [excludeHeaders=[]] - Headers to exclude from matching
+ * @property {boolean} [matchBody=true] - Whether to match request body
+ * @property {boolean} [matchQuery=true] - Whether to match query properties
+ * @property {boolean} [caseSensitive=false] - Whether header matching is case-sensitive
+ */
+
+/**
+ * @typedef {Object} SnapshotRecorderOptions
+ * @property {string} [snapshotPath] - Path to save/load snapshots
+ * @property {import('./snapshot-utils').SnapshotMode} [mode='record'] - Mode: 'record' or 'playback'
+ * @property {number} [maxSnapshots=Infinity] - Maximum number of snapshots to keep
+ * @property {boolean} [autoFlush=false] - Whether to automatically flush snapshots to disk
+ * @property {number} [flushInterval=30000] - Auto-flush interval in milliseconds (default: 30 seconds)
+ * @property {Array<string|RegExp>} [excludeUrls=[]] - URLs to exclude from recording
+ * @property {function} [shouldRecord=null] - Function to filter requests for recording
+ * @property {function} [shouldPlayback=null] - Function to filter requests
+ */
+
+/**
+ * @typedef {Object} SnapshotFormattedRequest
+ * @property {string} method - HTTP method (e.g. 'GET', 'POST', etc.)
+ * @property {string} url - Full URL of the request (with query parameters if matchQuery is true)
+ * @property {import('./snapshot-utils').NormalizedHeaders} headers - Normalized headers as a lowercase object
+ * @property {string} body - Request body (optional, only if matchBody is true)
+ */
+
+/**
+ * @typedef {Object} SnapshotInfo
+ * @property {string} hash - Hash key for the snapshot
+ * @property {SnapshotEntryRequest} request - The request object
+ * @property {number} responseCount - Number of responses recorded for this request
+ * @property {number} callCount - Number of times this snapshot has been called
+ * @property {string} timestamp - ISO timestamp of when the snapshot was created
+ */
+
+/**
+ * Formats a request for consistent snapshot storage
+ * Caches normalized headers to avoid repeated processing
+ *
+ * @param {SnapshotRequestOptions} opts - Request options
+ * @param {import('./snapshot-utils').HeaderFilters} headerFilters - Cached header sets for performance
+ * @param {SnapshotRecorderMatchOptions} [matchOptions] - Matching options for headers and body
+ * @returns {SnapshotFormattedRequest} - Formatted request object
+ */
+function formatRequestKey (opts, headerFilters, matchOptions = {}) {
+  const url = new URL(opts.path, opts.origin)
+
+  // Cache normalized headers if not already done
+  const normalized = opts._normalizedHeaders || normalizeHeaders(opts.headers)
+  if (!opts._normalizedHeaders) {
+    opts._normalizedHeaders = normalized
+  }
+
+  return {
+    method: opts.method || 'GET',
+    url: matchOptions.matchQuery !== false ? url.toString() : `${url.origin}${url.pathname}`,
+    headers: filterHeadersForMatching(normalized, headerFilters, matchOptions),
+    body: matchOptions.matchBody !== false && opts.body ? String(opts.body) : ''
+  }
+}
+
+/**
+ * Filters headers based on matching configuration
+ *
+ * @param {import('./snapshot-utils').Headers} headers - Headers to filter
+ * @param {import('./snapshot-utils').HeaderFilters} headerFilters - Cached sets for ignore, exclude, and match headers
+ * @param {SnapshotRecorderMatchOptions} [matchOptions] - Matching options for headers
+ */
+function filterHeadersForMatching (headers, headerFilters, matchOptions = {}) {
+  if (!headers || typeof headers !== 'object') return {}
+
+  const {
+    caseSensitive = false
+  } = matchOptions
+
+  const filtered = {}
+  const { ignore, exclude, match } = headerFilters
+
+  for (const [key, value] of Object.entries(headers)) {
+    const headerKey = caseSensitive ? key : key.toLowerCase()
+
+    // Skip if in exclude list (for security)
+    if (exclude.has(headerKey)) continue
+
+    // Skip if in ignore list (for matching)
+    if (ignore.has(headerKey)) continue
+
+    // If matchHeaders is specified, only include those headers
+    if (match.size !== 0) {
+      if (!match.has(headerKey)) continue
+    }
+
+    filtered[headerKey] = value
+  }
+
+  return filtered
+}
+
+/**
+ * Filters headers for storage (only excludes sensitive headers)
+ *
+ * @param {import('./snapshot-utils').Headers} headers - Headers to filter
+ * @param {import('./snapshot-utils').HeaderFilters} headerFilters - Cached sets for ignore, exclude, and match headers
+ * @param {SnapshotRecorderMatchOptions} [matchOptions] - Matching options for headers
+ */
+function filterHeadersForStorage (headers, headerFilters, matchOptions = {}) {
+  if (!headers || typeof headers !== 'object') return {}
+
+  const {
+    caseSensitive = false
+  } = matchOptions
+
+  const filtered = {}
+  const { exclude: excludeSet } = headerFilters
+
+  for (const [key, value] of Object.entries(headers)) {
+    const headerKey = caseSensitive ? key : key.toLowerCase()
+
+    // Skip if in exclude list (for security)
+    if (excludeSet.has(headerKey)) continue
+
+    filtered[headerKey] = value
+  }
+
+  return filtered
+}
+
+/**
+ * Creates a hash key for request matching
+ * Properly orders headers to avoid conflicts and uses crypto hashing when available
+ *
+ * @param {SnapshotFormattedRequest} formattedRequest - Request object
+ * @returns {string} - Base64url encoded hash of the request
+ */
+function createRequestHash (formattedRequest) {
+  const parts = [
+    formattedRequest.method,
+    formattedRequest.url
+  ]
+
+  // Process headers in a deterministic way to avoid conflicts
+  if (formattedRequest.headers && typeof formattedRequest.headers === 'object') {
+    const headerKeys = Object.keys(formattedRequest.headers).sort()
+    for (const key of headerKeys) {
+      const values = Array.isArray(formattedRequest.headers[key])
+        ? formattedRequest.headers[key]
+        : [formattedRequest.headers[key]]
+
+      // Add header name
+      parts.push(key)
+
+      // Add all values for this header, sorted for consistency
+      for (const value of values.sort()) {
+        parts.push(String(value))
+      }
+    }
+  }
+
+  // Add body
+  parts.push(formattedRequest.body)
+
+  const content = parts.join('|')
+
+  return hashId(content)
+}
+
+class SnapshotRecorder {
+  /** @type {NodeJS.Timeout | null} */
+  #flushTimeout
+
+  /** @type {import('./snapshot-utils').IsUrlExcluded} */
+  #isUrlExcluded
+
+  /** @type {Map<string, SnapshotEntry>} */
+  #snapshots = new Map()
+
+  /** @type {string|undefined} */
+  #snapshotPath
+
+  /** @type {number} */
+  #maxSnapshots = Infinity
+
+  /** @type {boolean} */
+  #autoFlush = false
+
+  /** @type {import('./snapshot-utils').HeaderFilters} */
+  #headerFilters
+
+  /**
+   * Creates a new SnapshotRecorder instance
+   * @param {SnapshotRecorderOptions&SnapshotRecorderMatchOptions} [options={}] - Configuration options for the recorder
+   */
+  constructor (options = {}) {
+    this.#snapshotPath = options.snapshotPath
+    this.#maxSnapshots = options.maxSnapshots || Infinity
+    this.#autoFlush = options.autoFlush || false
+    this.flushInterval = options.flushInterval || 30000 // 30 seconds default
+    this._flushTimer = null
+
+    // Matching configuration
+    /** @type {Required<SnapshotRecorderMatchOptions>} */
+    this.matchOptions = {
+      matchHeaders: options.matchHeaders || [], // empty means match all headers
+      ignoreHeaders: options.ignoreHeaders || [],
+      excludeHeaders: options.excludeHeaders || [],
+      matchBody: options.matchBody !== false, // default: true
+      matchQuery: options.matchQuery !== false, // default: true
+      caseSensitive: options.caseSensitive || false
+    }
+
+    // Cache processed header sets to avoid recreating them on every request
+    this.#headerFilters = createHeaderFilters(this.matchOptions)
+
+    // Request filtering callbacks
+    this.shouldRecord = options.shouldRecord || (() => true) // function(requestOpts) -> boolean
+    this.shouldPlayback = options.shouldPlayback || (() => true) // function(requestOpts) -> boolean
+
+    // URL pattern filtering
+    this.#isUrlExcluded = isUrlExcludedFactory(options.excludeUrls) // Array of regex patterns or strings
+
+    // Start auto-flush timer if enabled
+    if (this.#autoFlush && this.#snapshotPath) {
+      this.#startAutoFlush()
+    }
+  }
+
+  /**
+   * Records a request-response interaction
+   * @param {SnapshotRequestOptions} requestOpts - Request options
+   * @param {SnapshotEntryResponse} response - Response data to record
+   * @return {Promise<void>} - Resolves when the recording is complete
+   */
+  async record (requestOpts, response) {
+    // Check if recording should be filtered out
+    if (!this.shouldRecord(requestOpts)) {
+      return // Skip recording
+    }
+
+    // Check URL exclusion patterns
+    if (this.isUrlExcluded(requestOpts)) {
+      return // Skip recording
+    }
+
+    const request = formatRequestKey(requestOpts, this.#headerFilters, this.matchOptions)
+    const hash = createRequestHash(request)
+
+    // Extract response data - always store body as base64
+    const normalizedHeaders = normalizeHeaders(response.headers)
+
+    /** @type {SnapshotEntryResponse} */
+    const responseData = {
+      statusCode: response.statusCode,
+      headers: filterHeadersForStorage(normalizedHeaders, this.#headerFilters, this.matchOptions),
+      body: Buffer.isBuffer(response.body)
+        ? response.body.toString('base64')
+        : Buffer.from(String(response.body || '')).toString('base64'),
+      trailers: response.trailers
+    }
+
+    // Remove oldest snapshot if we exceed maxSnapshots limit
+    if (this.#snapshots.size >= this.#maxSnapshots && !this.#snapshots.has(hash)) {
+      const oldestKey = this.#snapshots.keys().next().value
+      this.#snapshots.delete(oldestKey)
+    }
+
+    // Support sequential responses - if snapshot exists, add to responses array
+    const existingSnapshot = this.#snapshots.get(hash)
+    if (existingSnapshot && existingSnapshot.responses) {
+      existingSnapshot.responses.push(responseData)
+      existingSnapshot.timestamp = new Date().toISOString()
+    } else {
+      this.#snapshots.set(hash, {
+        request,
+        responses: [responseData], // Always store as array for consistency
+        callCount: 0,
+        timestamp: new Date().toISOString()
+      })
+    }
+
+    // Auto-flush if enabled
+    if (this.#autoFlush && this.#snapshotPath) {
+      this.#scheduleFlush()
+    }
+  }
+
+  /**
+   * Checks if a URL should be excluded from recording/playback
+   * @param {SnapshotRequestOptions} requestOpts - Request options to check
+   * @returns {boolean} - True if URL is excluded
+   */
+  isUrlExcluded (requestOpts) {
+    const url = new URL(requestOpts.path, requestOpts.origin).toString()
+    return this.#isUrlExcluded(url)
+  }
+
+  /**
+   * Finds a matching snapshot for the given request
+   * Returns the appropriate response based on call count for sequential responses
+   *
+   * @param {SnapshotRequestOptions} requestOpts - Request options to match
+   * @returns {SnapshotEntry&Record<'response', SnapshotEntryResponse>|undefined} - Matching snapshot response or undefined if not found
+   */
+  findSnapshot (requestOpts) {
+    // Check if playback should be filtered out
+    if (!this.shouldPlayback(requestOpts)) {
+      return undefined // Skip playback
+    }
+
+    // Check URL exclusion patterns
+    if (this.isUrlExcluded(requestOpts)) {
+      return undefined // Skip playback
+    }
+
+    const request = formatRequestKey(requestOpts, this.#headerFilters, this.matchOptions)
+    const hash = createRequestHash(request)
+    const snapshot = this.#snapshots.get(hash)
+
+    if (!snapshot) return undefined
+
+    // Handle sequential responses
+    const currentCallCount = snapshot.callCount || 0
+    const responseIndex = Math.min(currentCallCount, snapshot.responses.length - 1)
+    snapshot.callCount = currentCallCount + 1
+
+    return {
+      ...snapshot,
+      response: snapshot.responses[responseIndex]
+    }
+  }
+
+  /**
+   * Loads snapshots from file
+   * @param {string} [filePath] - Optional file path to load snapshots from
+   * @return {Promise<void>} - Resolves when snapshots are loaded
+   */
+  async loadSnapshots (filePath) {
+    const path = filePath || this.#snapshotPath
+    if (!path) {
+      throw new InvalidArgumentError('Snapshot path is required')
+    }
+
+    try {
+      const data = await readFile(resolve(path), 'utf8')
+      const parsed = JSON.parse(data)
+
+      // Convert array format back to Map
+      if (Array.isArray(parsed)) {
+        this.#snapshots.clear()
+        for (const { hash, snapshot } of parsed) {
+          this.#snapshots.set(hash, snapshot)
+        }
+      } else {
+        // Legacy object format
+        this.#snapshots = new Map(Object.entries(parsed))
+      }
+    } catch (error) {
+      if (error.code === 'ENOENT') {
+        // File doesn't exist yet - that's ok for recording mode
+        this.#snapshots.clear()
+      } else {
+        throw new UndiciError(`Failed to load snapshots from ${path}`, { cause: error })
+      }
+    }
+  }
+
+  /**
+   * Saves snapshots to file
+   *
+   * @param {string} [filePath] - Optional file path to save snapshots
+   * @returns {Promise<void>} - Resolves when snapshots are saved
+   */
+  async saveSnapshots (filePath) {
+    const path = filePath || this.#snapshotPath
+    if (!path) {
+      throw new InvalidArgumentError('Snapshot path is required')
+    }
+
+    const resolvedPath = resolve(path)
+
+    // Ensure directory exists
+    await mkdir(dirname(resolvedPath), { recursive: true })
+
+    // Convert Map to serializable format
+    const data = Array.from(this.#snapshots.entries()).map(([hash, snapshot]) => ({
+      hash,
+      snapshot
+    }))
+
+    await writeFile(resolvedPath, JSON.stringify(data, null, 2), { flush: true })
+  }
+
+  /**
+   * Clears all recorded snapshots
+   * @returns {void}
+   */
+  clear () {
+    this.#snapshots.clear()
+  }
+
+  /**
+   * Gets all recorded snapshots
+   * @return {Array<SnapshotEntry>} - Array of all recorded snapshots
+   */
+  getSnapshots () {
+    return Array.from(this.#snapshots.values())
+  }
+
+  /**
+   * Gets snapshot count
+   * @return {number} - Number of recorded snapshots
+   */
+  size () {
+    return this.#snapshots.size
+  }
+
+  /**
+   * Resets call counts for all snapshots (useful for test cleanup)
+   * @returns {void}
+   */
+  resetCallCounts () {
+    for (const snapshot of this.#snapshots.values()) {
+      snapshot.callCount = 0
+    }
+  }
+
+  /**
+   * Deletes a specific snapshot by request options
+   * @param {SnapshotRequestOptions} requestOpts - Request options to match
+   * @returns {boolean} - True if snapshot was deleted, false if not found
+   */
+  deleteSnapshot (requestOpts) {
+    const request = formatRequestKey(requestOpts, this.#headerFilters, this.matchOptions)
+    const hash = createRequestHash(request)
+    return this.#snapshots.delete(hash)
+  }
+
+  /**
+   * Gets information about a specific snapshot
+   * @param {SnapshotRequestOptions} requestOpts - Request options to match
+   * @returns {SnapshotInfo|null} - Snapshot information or null if not found
+   */
+  getSnapshotInfo (requestOpts) {
+    const request = formatRequestKey(requestOpts, this.#headerFilters, this.matchOptions)
+    const hash = createRequestHash(request)
+    const snapshot = this.#snapshots.get(hash)
+
+    if (!snapshot) return null
+
+    return {
+      hash,
+      request: snapshot.request,
+      responseCount: snapshot.responses ? snapshot.responses.length : (snapshot.response ? 1 : 0), // .response for legacy snapshots
+      callCount: snapshot.callCount || 0,
+      timestamp: snapshot.timestamp
+    }
+  }
+
+  /**
+   * Replaces all snapshots with new data (full replacement)
+   * @param {Array<{hash: string; snapshot: SnapshotEntry}>|Record<string, SnapshotEntry>} snapshotData - New snapshot data to replace existing ones
+   * @returns {void}
+   */
+  replaceSnapshots (snapshotData) {
+    this.#snapshots.clear()
+
+    if (Array.isArray(snapshotData)) {
+      for (const { hash, snapshot } of snapshotData) {
+        this.#snapshots.set(hash, snapshot)
+      }
+    } else if (snapshotData && typeof snapshotData === 'object') {
+      // Legacy object format
+      this.#snapshots = new Map(Object.entries(snapshotData))
+    }
+  }
+
+  /**
+   * Starts the auto-flush timer
+   * @returns {void}
+   */
+  #startAutoFlush () {
+    return this.#scheduleFlush()
+  }
+
+  /**
+   * Stops the auto-flush timer
+   * @returns {void}
+   */
+  #stopAutoFlush () {
+    if (this.#flushTimeout) {
+      clearTimeout(this.#flushTimeout)
+      // Ensure any pending flush is completed
+      this.saveSnapshots().catch(() => {
+      // Ignore flush errors
+      })
+      this.#flushTimeout = null
+    }
+  }
+
+  /**
+   * Schedules a flush (debounced to avoid excessive writes)
+   */
+  #scheduleFlush () {
+    this.#flushTimeout = setTimeout(() => {
+      this.saveSnapshots().catch(() => {
+        // Ignore flush errors
+      })
+      if (this.#autoFlush) {
+        this.#flushTimeout?.refresh()
+      } else {
+        this.#flushTimeout = null
+      }
+    }, 1000) // 1 second debounce
+  }
+
+  /**
+   * Cleanup method to stop timers
+   * @returns {void}
+   */
+  destroy () {
+    this.#stopAutoFlush()
+    if (this.#flushTimeout) {
+      clearTimeout(this.#flushTimeout)
+      this.#flushTimeout = null
+    }
+  }
+
+  /**
+   * Async close method that saves all recordings and performs cleanup
+   * @returns {Promise<void>}
+   */
+  async close () {
+    // Save any pending recordings if we have a snapshot path
+    if (this.#snapshotPath && this.#snapshots.size !== 0) {
+      await this.saveSnapshots()
+    }
+
+    // Perform cleanup
+    this.destroy()
+  }
+}
+
+module.exports = { SnapshotRecorder, formatRequestKey, createRequestHash, filterHeadersForMatching, filterHeadersForStorage, createHeaderFilters }
diff --git a/vanilla/node_modules/undici/lib/mock/snapshot-utils.js b/vanilla/node_modules/undici/lib/mock/snapshot-utils.js
new file mode 100644
index 0000000..a14b69c
--- /dev/null
+++ b/vanilla/node_modules/undici/lib/mock/snapshot-utils.js
@@ -0,0 +1,158 @@
+'use strict'
+
+const { InvalidArgumentError } = require('../core/errors')
+const { runtimeFeatures } = require('../util/runtime-features.js')
+
+/**
+ * @typedef {Object} HeaderFilters
+ * @property {Set<string>} ignore - Set of headers to ignore for matching
+ * @property {Set<string>} exclude - Set of headers to exclude from matching
+ * @property {Set<string>} match - Set of headers to match (empty means match
+ */
+
+/**
+ * Creates cached header sets for performance
+ *
+ * @param {import('./snapshot-recorder').SnapshotRecorderMatchOptions} matchOptions - Matching options for headers
+ * @returns {HeaderFilters} - Cached sets for ignore, exclude, and match headers
+ */
+function createHeaderFilters (matchOptions = {}) {
+  const { ignoreHeaders = [], excludeHeaders = [], matchHeaders = [], caseSensitive = false } = matchOptions
+
+  return {
+    ignore: new Set(ignoreHeaders.map(header => caseSensitive ? header : header.toLowerCase())),
+    exclude: new Set(excludeHeaders.map(header => caseSensitive ? header : header.toLowerCase())),
+    match: new Set(matchHeaders.map(header => caseSensitive ? header : header.toLowerCase()))
+  }
+}
+
+const crypto = runtimeFeatures.has('crypto')
+  ? require('node:crypto')
+  : null
+
+/**
+ * @callback HashIdFunction
+ * @param {string} value - The value to hash
+ * @returns {string} - The base64url encoded hash of the value
+ */
+
+/**
+ * Generates a hash for a given value
+ * @type {HashIdFunction}
+ */
+const hashId = crypto?.hash
+  ? (value) => crypto.hash('sha256', value, 'base64url')
+  : (value) => Buffer.from(value).toString('base64url')
+
+/**
+ * @typedef {(url: string) => boolean} IsUrlExcluded Checks if a URL matches any of the exclude patterns
+ */
+
+/** @typedef {{[key: Lowercase<string>]: string}} NormalizedHeaders */
+/** @typedef {Array<string>} UndiciHeaders */
+/** @typedef {Record<string, string|string[]>} Headers */
+
+/**
+ * @param {*} headers
+ * @returns {headers is UndiciHeaders}
+ */
+function isUndiciHeaders (headers) {
+  return Array.isArray(headers) && (headers.length & 1) === 0
+}
+
+/**
+ * Factory function to create a URL exclusion checker
+ * @param {Array<string| RegExp>} [excludePatterns=[]] - Array of patterns to exclude
+ * @returns {IsUrlExcluded} - A function that checks if a URL matches any of the exclude patterns
+ */
+function isUrlExcludedFactory (excludePatterns = []) {
+  if (excludePatterns.length === 0) {
+    return () => false
+  }
+
+  return function isUrlExcluded (url) {
+    let urlLowerCased
+
+    for (const pattern of excludePatterns) {
+      if (typeof pattern === 'string') {
+        if (!urlLowerCased) {
+          // Convert URL to lowercase only once
+          urlLowerCased = url.toLowerCase()
+        }
+        // Simple string match (case-insensitive)
+        if (urlLowerCased.includes(pattern.toLowerCase())) {
+          return true
+        }
+      } else if (pattern instanceof RegExp) {
+        // Regex pattern match
+        if (pattern.test(url)) {
+          return true
+        }
+      }
+    }
+
+    return false
+  }
+}
+
+/**
+ * Normalizes headers for consistent comparison
+ *
+ * @param {Object|UndiciHeaders} headers - Headers to normalize
+ * @returns {NormalizedHeaders} - Normalized headers as a lowercase object
+ */
+function normalizeHeaders (headers) {
+  /** @type {NormalizedHeaders} */
+  const normalizedHeaders = {}
+
+  if (!headers) return normalizedHeaders
+
+  // Handle array format (undici internal format: [name, value, name, value, ...])
+  if (isUndiciHeaders(headers)) {
+    for (let i = 0; i < headers.length; i += 2) {
+      const key = headers[i]
+      const value = headers[i + 1]
+      if (key && value !== undefined) {
+        // Convert Buffers to strings if needed
+        const keyStr = Buffer.isBuffer(key) ? key.toString() : key
+        const valueStr = Buffer.isBuffer(value) ? value.toString() : value
+        normalizedHeaders[keyStr.toLowerCase()] = valueStr
+      }
+    }
+    return normalizedHeaders
+  }
+
+  // Handle object format
+  if (headers && typeof headers === 'object') {
+    for (const [key, value] of Object.entries(headers)) {
+      if (key && typeof key === 'string') {
+        normalizedHeaders[key.toLowerCase()] = Array.isArray(value) ? value.join(', ') : String(value)
+      }
+    }
+  }
+
+  return normalizedHeaders
+}
+
+const validSnapshotModes = /** @type {const} */ (['record', 'playback', 'update'])
+
+/** @typedef {typeof validSnapshotModes[number]} SnapshotMode */
+
+/**
+ * @param {*} mode - The snapshot mode to validate
+ * @returns {asserts mode is SnapshotMode}
+ */
+function validateSnapshotMode (mode) {
+  if (!validSnapshotModes.includes(mode)) {
+    throw new InvalidArgumentError(`Invalid snapshot mode: ${mode}. Must be one of: ${validSnapshotModes.join(', ')}`)
+  }
+}
+
+module.exports = {
+  createHeaderFilters,
+  hashId,
+  isUndiciHeaders,
+  normalizeHeaders,
+  isUrlExcludedFactory,
+  validateSnapshotMode
+}