Adding upstream version 5.28.2+dfsg1+~cs23.11.12.3.upstream/5.28.2+dfsg1+_cs23.11.12.3upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

9 files changed, 955 insertions, 0 deletions

diff --git a/lib/mock/mock-agent.js b/lib/mock/mock-agent.js
new file mode 100644
index 0000000..828e8af
--- /dev/null
+++ b/lib/mock/mock-agent.js
@@ -0,0 +1,171 @@
+'use strict'
+
+const { kClients } = require('../core/symbols')
+const Agent = require('../agent')
+const {
+  kAgent,
+  kMockAgentSet,
+  kMockAgentGet,
+  kDispatches,
+  kIsMockActive,
+  kNetConnect,
+  kGetNetConnect,
+  kOptions,
+  kFactory
+} = require('./mock-symbols')
+const MockClient = require('./mock-client')
+const MockPool = require('./mock-pool')
+const { matchValue, buildMockOptions } = require('./mock-utils')
+const { InvalidArgumentError, UndiciError } = require('../core/errors')
+const Dispatcher = require('../dispatcher')
+const Pluralizer = require('./pluralizer')
+const PendingInterceptorsFormatter = require('./pending-interceptors-formatter')
+
+class FakeWeakRef {
+  constructor (value) {
+    this.value = value
+  }
+
+  deref () {
+    return this.value
+  }
+}
+
+class MockAgent extends Dispatcher {
+  constructor (opts) {
+    super(opts)
+
+    this[kNetConnect] = true
+    this[kIsMockActive] = true
+
+    // Instantiate Agent and encapsulate
+    if ((opts && opts.agent && typeof opts.agent.dispatch !== 'function')) {
+      throw new InvalidArgumentError('Argument opts.agent must implement Agent')
+    }
+    const agent = opts && opts.agent ? opts.agent : new Agent(opts)
+    this[kAgent] = agent
+
+    this[kClients] = agent[kClients]
+    this[kOptions] = buildMockOptions(opts)
+  }
+
+  get (origin) {
+    let dispatcher = this[kMockAgentGet](origin)
+
+    if (!dispatcher) {
+      dispatcher = this[kFactory](origin)
+      this[kMockAgentSet](origin, dispatcher)
+    }
+    return dispatcher
+  }
+
+  dispatch (opts, handler) {
+    // Call MockAgent.get to perform additional setup before dispatching as normal
+    this.get(opts.origin)
+    return this[kAgent].dispatch(opts, handler)
+  }
+
+  async close () {
+    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
+  }
+
+  // This is required to bypass issues caused by using global symbols - see:
+  // https://github.com/nodejs/undici/issues/1447
+  get isMockActive () {
+    return this[kIsMockActive]
+  }
+
+  [kMockAgentSet] (origin, dispatcher) {
+    this[kClients].set(origin, new FakeWeakRef(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 ref = this[kClients].get(origin)
+    if (ref) {
+      return ref.deref()
+    }
+
+    // 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, nonExplicitRef] of Array.from(this[kClients])) {
+      const nonExplicitDispatcher = nonExplicitRef.deref()
+      if (nonExplicitDispatcher && typeof keyMatcher !== 'string' && matchValue(keyMatcher, origin)) {
+        const dispatcher = this[kFactory](origin)
+        this[kMockAgentSet](origin, dispatcher)
+        dispatcher[kDispatches] = nonExplicitDispatcher[kDispatches]
+        return dispatcher
+      }
+    }
+  }
+
+  [kGetNetConnect] () {
+    return this[kNetConnect]
+  }
+
+  pendingInterceptors () {
+    const mockAgentClients = this[kClients]
+
+    return Array.from(mockAgentClients.entries())
+      .flatMap(([origin, scope]) => scope.deref()[kDispatches].map(dispatch => ({ ...dispatch, origin })))
+      .filter(({ pending }) => pending)
+  }
+
+  assertNoPendingInterceptors ({ pendingInterceptorsFormatter = new PendingInterceptorsFormatter() } = {}) {
+    const pending = this.pendingInterceptors()
+
+    if (pending.length === 0) {
+      return
+    }
+
+    const pluralizer = new Pluralizer('interceptor', 'interceptors').pluralize(pending.length)
+
+    throw new UndiciError(`
+${pluralizer.count} ${pluralizer.noun} ${pluralizer.is} pending:
+
+${pendingInterceptorsFormatter.format(pending)}
+`.trim())
+  }
+}
+
+module.exports = MockAgent
diff --git a/lib/mock/mock-client.js b/lib/mock/mock-client.js
new file mode 100644
index 0000000..5f31215
--- /dev/null
+++ b/lib/mock/mock-client.js
@@ -0,0 +1,59 @@
+'use strict'
+
+const { promisify } = require('util')
+const Client = require('../client')
+const { buildMockDispatch } = require('./mock-utils')
+const {
+  kDispatches,
+  kMockAgent,
+  kClose,
+  kOriginalClose,
+  kOrigin,
+  kOriginalDispatch,
+  kConnected
+} = 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) {
+    super(origin, opts)
+
+    if (!opts || !opts.agent || typeof opts.agent.dispatch !== 'function') {
+      throw new InvalidArgumentError('Argument opts.agent must implement Agent')
+    }
+
+    this[kMockAgent] = opts.agent
+    this[kOrigin] = origin
+    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, this[kDispatches])
+  }
+
+  async [kClose] () {
+    await promisify(this[kOriginalClose])()
+    this[kConnected] = 0
+    this[kMockAgent][Symbols.kClients].delete(this[kOrigin])
+  }
+}
+
+module.exports = MockClient
diff --git a/lib/mock/mock-errors.js b/lib/mock/mock-errors.js
new file mode 100644
index 0000000..5442c0e
--- /dev/null
+++ b/lib/mock/mock-errors.js
@@ -0,0 +1,17 @@
+'use strict'
+
+const { UndiciError } = require('../core/errors')
+
+class MockNotMatchedError extends UndiciError {
+  constructor (message) {
+    super(message)
+    Error.captureStackTrace(this, MockNotMatchedError)
+    this.name = 'MockNotMatchedError'
+    this.message = message || 'The request does not match any registered mock dispatches'
+    this.code = 'UND_MOCK_ERR_MOCK_NOT_MATCHED'
+  }
+}
+
+module.exports = {
+  MockNotMatchedError
+}
diff --git a/lib/mock/mock-interceptor.js b/lib/mock/mock-interceptor.js
new file mode 100644
index 0000000..781e477
--- /dev/null
+++ b/lib/mock/mock-interceptor.js
@@ -0,0 +1,206 @@
+'use strict'
+
+const { getResponseData, buildKey, addMockDispatch } = require('./mock-utils')
+const {
+  kDispatches,
+  kDispatchKey,
+  kDefaultHeaders,
+  kDefaultTrailers,
+  kContentLength,
+  kMockDispatch
+} = require('./mock-symbols')
+const { InvalidArgumentError } = require('../core/errors')
+const { buildURL } = 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 = buildURL(opts.path, opts.query)
+      } else {
+        // Matches https://github.com/nodejs/undici/blob/main/lib/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[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 (statusCode, data, responseOptions) {
+    if (typeof statusCode === 'undefined') {
+      throw new InvalidArgumentError('statusCode must be defined')
+    }
+    if (typeof data === 'undefined') {
+      throw new InvalidArgumentError('data must be defined')
+    }
+    if (typeof responseOptions !== 'object') {
+      throw new InvalidArgumentError('responseOptions must be an object')
+    }
+  }
+
+  /**
+   * Mock an undici request with a defined reply.
+   */
+  reply (replyData) {
+    // Values of reply aren't available right now as they
+    // can only be available when the reply callback is invoked.
+    if (typeof replyData === '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 = replyData(opts)
+
+        // Check if it is in the right format
+        if (typeof resolvedData !== 'object') {
+          throw new InvalidArgumentError('reply options callback must return an object')
+        }
+
+        const { statusCode, data = '', responseOptions = {} } = resolvedData
+        this.validateReplyParameters(statusCode, data, responseOptions)
+        // Since the values can be obtained immediately we return them
+        // from this higher order function that will be resolved later.
+        return {
+          ...this.createMockScopeDispatchData(statusCode, data, responseOptions)
+        }
+      }
+
+      // 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)
+      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 [statusCode, data = '', responseOptions = {}] = [...arguments]
+    this.validateReplyParameters(statusCode, data, responseOptions)
+
+    // Send in-already provided data like usual
+    const dispatchData = this.createMockScopeDispatchData(statusCode, data, responseOptions)
+    const newMockDispatch = addMockDispatch(this[kDispatches], this[kDispatchKey], dispatchData)
+    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 })
+    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/lib/mock/mock-pool.js b/lib/mock/mock-pool.js
new file mode 100644
index 0000000..0a3a7cd
--- /dev/null
+++ b/lib/mock/mock-pool.js
@@ -0,0 +1,59 @@
+'use strict'
+
+const { promisify } = require('util')
+const Pool = require('../pool')
+const { buildMockDispatch } = require('./mock-utils')
+const {
+  kDispatches,
+  kMockAgent,
+  kClose,
+  kOriginalClose,
+  kOrigin,
+  kOriginalDispatch,
+  kConnected
+} = 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) {
+    super(origin, opts)
+
+    if (!opts || !opts.agent || typeof opts.agent.dispatch !== 'function') {
+      throw new InvalidArgumentError('Argument opts.agent must implement Agent')
+    }
+
+    this[kMockAgent] = opts.agent
+    this[kOrigin] = origin
+    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, this[kDispatches])
+  }
+
+  async [kClose] () {
+    await promisify(this[kOriginalClose])()
+    this[kConnected] = 0
+    this[kMockAgent][Symbols.kClients].delete(this[kOrigin])
+  }
+}
+
+module.exports = MockPool
diff --git a/lib/mock/mock-symbols.js b/lib/mock/mock-symbols.js
new file mode 100644
index 0000000..8c4cbb6
--- /dev/null
+++ b/lib/mock/mock-symbols.js
@@ -0,0 +1,23 @@
+'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'),
+  kOrigin: Symbol('origin'),
+  kIsMockActive: Symbol('is mock active'),
+  kNetConnect: Symbol('net connect'),
+  kGetNetConnect: Symbol('get net connect'),
+  kConnected: Symbol('connected')
+}
diff --git a/lib/mock/mock-utils.js b/lib/mock/mock-utils.js
new file mode 100644
index 0000000..42ea185
--- /dev/null
+++ b/lib/mock/mock-utils.js
@@ -0,0 +1,351 @@
+'use strict'
+
+const { MockNotMatchedError } = require('./mock-errors')
+const {
+  kDispatches,
+  kMockAgent,
+  kOriginalDispatch,
+  kOrigin,
+  kGetNetConnect
+} = require('./mock-symbols')
+const { buildURL, nop } = require('../core/util')
+const { STATUS_CODES } = require('http')
+const {
+  types: {
+    isPromise
+  }
+} = require('util')
+
+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 safeUrl (path) {
+  if (typeof path !== 'string') {
+    return path
+  }
+
+  const pathSegments = path.split('?')
+
+  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 (typeof data === 'object') {
+    return JSON.stringify(data)
+  } else {
+    return data.toString()
+  }
+}
+
+function getMockDispatch (mockDispatches, key) {
+  const basePath = key.query ? buildURL(key.path, key.query) : key.path
+  const resolvedPath = typeof basePath === 'string' ? safeUrl(basePath) : basePath
+
+  // Match path
+  let matchedMockDispatches = mockDispatches.filter(({ consumed }) => !consumed).filter(({ path }) => 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}'`)
+  }
+
+  // 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 '${key.body}'`)
+  }
+
+  // Match headers
+  matchedMockDispatches = matchedMockDispatches.filter((mockDispatch) => matchHeaders(mockDispatch, key.headers))
+  if (matchedMockDispatches.length === 0) {
+    throw new MockNotMatchedError(`Mock dispatch not matched for headers '${typeof key.headers === 'object' ? JSON.stringify(key.headers) : key.headers}'`)
+  }
+
+  return matchedMockDispatches[0]
+}
+
+function addMockDispatch (mockDispatches, key, data) {
+  const baseData = { timesInvoked: 0, times: 1, persist: false, consumed: false }
+  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)
+  }
+}
+
+function buildKey (opts) {
+  const { path, method, body, headers, query } = opts
+  return {
+    path,
+    method,
+    body,
+    headers,
+    query
+  }
+}
+
+function generateKeyValues (data) {
+  return Object.entries(data).reduce((keyValuePairs, [key, value]) => [
+    ...keyValuePairs,
+    Buffer.from(`${key}`),
+    Array.isArray(value) ? value.map(x => Buffer.from(`${x}`)) : Buffer.from(`${value}`)
+  ], [])
+}
+
+/**
+ * @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
+  }
+
+  // Handle the request with a delay if necessary
+  if (typeof delay === 'number' && delay > 0) {
+    setTimeout(() => {
+      handleReply(this[kDispatches])
+    }, delay)
+  } else {
+    handleReply(this[kDispatches])
+  }
+
+  function handleReply (mockDispatches, _data = data) {
+    // 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.
+      body.then((newData) => handleReply(mockDispatches, newData))
+      return
+    }
+
+    const responseData = getResponseData(body)
+    const responseHeaders = generateKeyValues(headers)
+    const responseTrailers = generateKeyValues(trailers)
+
+    handler.abort = nop
+    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 instanceof MockNotMatchedError) {
+          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 buildMockOptions (opts) {
+  if (opts) {
+    const { agent, ...mockOptions } = opts
+    return mockOptions
+  }
+}
+
+module.exports = {
+  getResponseData,
+  getMockDispatch,
+  addMockDispatch,
+  deleteMockDispatch,
+  buildKey,
+  generateKeyValues,
+  matchValue,
+  getResponse,
+  getStatusText,
+  mockDispatch,
+  buildMockDispatch,
+  checkNetConnect,
+  buildMockOptions,
+  getHeaderByName
+}
diff --git a/lib/mock/pending-interceptors-formatter.js b/lib/mock/pending-interceptors-formatter.js
new file mode 100644
index 0000000..1bc7539
--- /dev/null
+++ b/lib/mock/pending-interceptors-formatter.js
@@ -0,0 +1,40 @@
+'use strict'
+
+const { Transform } = require('stream')
+const { Console } = require('console')
+
+/**
+ * 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 ? '✅' : '❌',
+        Invocations: timesInvoked,
+        Remaining: persist ? Infinity : times - timesInvoked
+      }))
+
+    this.logger.table(withPrettyHeaders)
+    return this.transform.read().toString()
+  }
+}
diff --git a/lib/mock/pluralizer.js b/lib/mock/pluralizer.js
new file mode 100644
index 0000000..47f150b
--- /dev/null
+++ b/lib/mock/pluralizer.js
@@ -0,0 +1,29 @@
+'use strict'
+
+const singulars = {
+  pronoun: 'it',
+  is: 'is',
+  was: 'was',
+  this: 'this'
+}
+
+const plurals = {
+  pronoun: 'they',
+  is: 'are',
+  was: 'were',
+  this: 'these'
+}
+
+module.exports = class Pluralizer {
+  constructor (singular, plural) {
+    this.singular = singular
+    this.plural = plural
+  }
+
+  pluralize (count) {
+    const one = count === 1
+    const keys = one ? singulars : plurals
+    const noun = one ? this.singular : this.plural
+    return { ...keys, count, noun }
+  }
+}