abstract_client.ts

/**
 * Testing dependencies
 */
import { assert } from 'chai'
import sinon from 'sinon'
import fs from 'fs'
import levelStore from 'mqtt-level-store'
import Store from '../src/lib/store'
import serverBuilder from './server_helpers_for_client_tests'
import handlePubrel from '../src/lib/handlers/pubrel'
import handle from '../src/lib/handlers/index'
import handlePublish from '../src/lib/handlers/publish'
import mqtt, {
	IClientOptions,
	IClientPublishOptions,
	IClientSubscribeOptions,
	ISubscriptionMap,
	ISubscriptionRequest,
} from '../src'
import { IPublishPacket, IPubrelPacket, ISubackPacket, QoS } from 'mqtt-packet'
import { DoneCallback, ErrorWithReasonCode } from 'src/lib/shared'
import { fail } from 'assert'
import { describe, it, beforeEach, afterEach } from 'node:test'

/**
 * These tests try to be consistent with names for servers (brokers) and clients,
 * but it can be confusing. To make it easier, here is a handy translation
 * chart:
 *
 * name           | meaning
 * ---------------|--------
 * client         | The MQTT.js client object being tested. A new instance is created for each test (by calling the `connect` function.)
 * server         | A mock broker that you can control. The same server instance is used for all tests, so only use this if you plan to clean up when you're done.
 * serverBuilder  | A factory that can make mock test servers (MQTT brokers). Useful if you need to do things that you can't (or don't want to) clean up after your test is done.
 * server2        | The name used for mock brokers that are created for an individual test and then destroyed.
 * serverClient   | An socket on the mock broker. This gets created when your client connects and gets collected when you're done with it.
 *
 * Also worth noting:
 *
 * `serverClient.disconnect()` does not disconnect that socket. Instead, it sends an MQTT disconnect packet.
 * If you want to disconnect the socket from the broker side, you probably want to use `serverClient.destroy()`
 * or `serverClient.stream.destroy()`.
 *
 */

export default function abstractTest(server, config, ports) {
	const version = config.protocolVersion || 4

	function connect(opts?: IClientOptions | string) {
		if (typeof opts === 'string') {
			opts = { host: opts }
		}
		opts = { ...config, ...opts } as IClientOptions
		return mqtt.connect(opts)
	}

	describe('closing', () => {
		it('should emit close if stream closes', function _test(t, done) {
			const client = connect()

			client.once('connect', () => {
				client.stream.end()
			})
			client.once('close', () => {
				client.end((err) => done(err))
			})
		})

		it('should mark the client as disconnected', function _test(t, done) {
			const client = connect()

			client.once('close', () => {
				client.end((err) => {
					if (!client.connected) {
						done(err)
					} else {
						done(new Error('Not marked as disconnected'))
					}
				})
				assert.isFalse(client.connected)
			})
			client.once('connect', () => {
				client.stream.end()
			})
		})

		it('should stop ping timer if stream closes', function _test(t, done) {
			const client = connect()

			client.once('close', () => {
				assert.notExists(client.pingTimer)
				client.end(true, (err) => done(err))
			})

			client.once('connect', () => {
				assert.exists(client.pingTimer)
				client.stream.end()
			})
		})

		it('should emit close after end called', function _test(t, done) {
			const client = connect()

			client.once('close', () => {
				done()
			})

			client.once('connect', () => {
				client.end()
			})
		})

		it('should emit end after end called and client must be disconnected', function _test(t, done) {
			const client = connect()

			client.once('end', () => {
				if (client.disconnected) {
					return done()
				}
				done(new Error('client must be disconnected'))
			})

			client.once('connect', () => {
				client.end()
			})
		})

		it('should pass store close error to end callback but not to end listeners (incomingStore)', function _test(t, done) {
			const store = new Store()
			const client = connect({ incomingStore: store })

			store.close = (cb) => {
				cb(new Error('test'))
			}
			client.once('end', (...args) => {
				if (args.length === 0) {
					return
				}
				throw new Error('no argument should be passed to event')
			})

			client.once('connect', () => {
				client.end((testError) => {
					if (testError && testError.message === 'test') {
						return done()
					}
					throw new Error('bad argument passed to callback')
				})
			})
		})

		it('should pass store close error to end callback but not to end listeners (outgoingStore)', function _test(t, done) {
			const store = new Store()
			const client = connect({ outgoingStore: store })

			store.close = (cb) => {
				cb(new Error('test'))
			}
			client.once('end', (...args) => {
				if (args.length === 0) {
					return
				}
				throw new Error('no argument should be passed to event')
			})

			client.once('connect', () => {
				client.end((testError) => {
					if (testError && testError.message === 'test') {
						return done()
					}
					throw new Error('bad argument passed to callback')
				})
			})
		})

		it('should return `this` if end called twice', function _test(t, done) {
			const client = connect()

			client.once('connect', () => {
				client.end()
				const value = client.end()
				if (value === client) {
					done()
				} else {
					done(new Error('Not returning client.'))
				}
			})
		})

		it('should emit end only on first client end', function _test(t, done) {
			const client = connect()

			client.once('end', () => {
				const timeout = setTimeout(() => done(), 200)
				client.once('end', () => {
					clearTimeout(timeout)
					done(new Error('end was emitted twice'))
				})
				client.end()
			})

			client.once('connect', () => {
				client.end()
			})
		})

		it('should stop ping timer after end called', function _test(t, done) {
			const client = connect()

			client.once('connect', () => {
				assert.exists(client.pingTimer)
				client.end((err) => {
					assert.notExists(client.pingTimer)
					done(err)
				})
			})
		})

		it('should be able to end even on a failed connection', function _test(t, done) {
			const client = connect({ host: 'this_hostname_should_not_exist' })

			const timeout = setTimeout(() => {
				done(new Error('Failed to end a disconnected client'))
			}, 500)

			setTimeout(() => {
				client.end((err) => {
					clearTimeout(timeout)
					done(err)
				})
			}, 200)
		})

		it('should emit end even on a failed connection', function _test(t, done) {
			const client = connect({ host: 'this_hostname_should_not_exist' })

			const timeout = setTimeout(() => {
				done(new Error('Disconnected client has failed to emit end'))
			}, 500)

			client.once('end', () => {
				clearTimeout(timeout)
				done()
			})

			// after 200ms manually invoke client.end
			setTimeout(() => {
				client.end.call(client)
			}, 200)
		})

		it.skip('should emit end only once for a reconnecting client', function _test(t, done) {
			// I want to fix this test, but it will take signficant work, so I am marking it as a skipping test right now.
			// Reason for it is that there are overlaps in the reconnectTimer and connectTimer. In the PR for this code
			// there will be gists showing the difference between a successful test here and a failed test. For now we
			// will add the retries syntax because of the flakiness.
			const client = connect({
				host: 'this_hostname_should_not_exist',
				connectTimeout: 10,
				reconnectPeriod: 20,
			})
			setTimeout(() => done(), 1000)
			const endCallback = () => {
				assert.strictEqual(
					spy.callCount,
					1,
					'end was emitted more than once for reconnecting client',
				)
			}

			const spy = sinon.spy(endCallback)
			client.on('end', spy)
			setTimeout(() => {
				client.end.call(client)
			}, 300)
		})
	})

	describe('connecting', () => {
		it('should connect to the broker', function _test(t, done) {
			const client = connect()
			client.on('error', done)

			server.once('client', () => {
				client.end((err) => done(err))
			})
		})

		it('should send a default client id', function _test(t, done) {
			const client = connect()
			client.on('error', done)

			server.once('client', (serverClient) => {
				serverClient.once('connect', (packet) => {
					assert.include(packet.clientId, 'mqttjs')
					client.end((err) => done(err))
				})
			})
		})

		it('should send be clean by default', function _test(t, done) {
			const client = connect()
			client.on('error', done)

			server.once('client', (serverClient) => {
				serverClient.once('connect', (packet) => {
					assert.strictEqual(packet.clean, true)
					done()
				})
			})
		})

		it('should connect with the given client id', function _test(t, done) {
			const client = connect({ clientId: 'testclient' })
			client.on('error', (err) => {
				throw err
			})

			server.once('client', (serverClient) => {
				serverClient.once('connect', (packet) => {
					assert.include(packet.clientId, 'testclient')
					client.end((err) => done(err))
				})
			})
		})

		it('should connect with the client id and unclean state', function _test(t, done) {
			const client = connect({ clientId: 'testclient', clean: false })
			client.on('error', (err) => {
				throw err
			})

			server.once('client', (serverClient) => {
				serverClient.once('connect', (packet) => {
					assert.include(packet.clientId, 'testclient')
					assert.isFalse(packet.clean)
					client.end(false, (err) => done(err))
				})
			})
		})

		it('should require a clientId with clean=false', function _test(t, done) {
			try {
				const client = connect({ clean: false })
				client.on('error', (err) => {
					done(err)
				})
			} catch (err) {
				assert.strictEqual(
					err.message,
					'Missing clientId for unclean clients',
				)
				done()
			}
		})

		it('should default to localhost', function _test(t, done) {
			const client = connect({ clientId: 'testclient' })
			client.on('error', (err) => {
				throw err
			})

			server.once('client', (serverClient) => {
				serverClient.once('connect', (packet) => {
					assert.include(packet.clientId, 'testclient')
					done()
				})
			})
		})

		it('should emit connect', function _test(t, done) {
			const client = connect()
			client.once('connect', (packet: mqtt.IConnackPacket) => {
				assert.equal(packet.cmd, 'connack')
				client.end(true, (err) => done(err))
			})
			client.once('error', done)
		})

		it('should provide connack packet with connect event', function _test(t, done) {
			const connack =
				version === 5
					? { reasonCode: 0, sessionPresent: undefined }
					: { returnCode: 0, sessionPresent: undefined }
			server.once('client', (serverClient) => {
				connack.sessionPresent = true
				serverClient.connack(connack)
				server.once('client', (serverClient2) => {
					connack.sessionPresent = false
					serverClient2.connack(connack)
				})
			})

			const client = connect()
			client.once('connect', (packet) => {
				assert.strictEqual(packet.sessionPresent, true)
				client.once('connect', (packet2) => {
					assert.strictEqual(packet2.sessionPresent, false)
					client.end((err) => done(err))
				})
			})
		})

		it('should mark the client as connected', function _test(t, done) {
			const client = connect()
			client.once('connect', () => {
				assert.isTrue(client.connected)
				client.end((err) => done(err))
			})
		})

		it('should emit error on invalid clientId', function _test(t, done) {
			const client = connect({ clientId: 'invalid' })
			client.once('connect', () => {
				done(new Error('Should not emit connect'))
			})
			client.once('error', (error: ErrorWithReasonCode) => {
				const value = version === 5 ? 128 : 2
				assert.strictEqual(error.code, value) // code for clientID identifer rejected
				client.end((err) => done(err))
			})
		})

		it('should emit error event if the socket refuses the connection', function _test(t, done) {
			// fake a port
			const client = connect({ port: 4557 })

			client.on('error', (e: any) => {
				assert.equal(e.code, 'ECONNREFUSED')
				client.end((err) => done(err))
			})
		})

		it('should have different client ids', function _test(t, done) {
			// bug identified in this test: the client.end callback is invoked twice, once when the `end`
			// method completes closing the stores and invokes the callback, and another time when the
			// stream is closed. When the stream is closed, for some reason the closeStores method is called
			// a second time.
			const client1 = connect()
			const client2 = connect()

			assert.notStrictEqual(
				client1.options.clientId,
				client2.options.clientId,
			)
			client1.end(true, () => {
				client2.end(true, () => {
					done()
				})
			})
		})
	})

	describe('handling offline states', () => {
		it('should emit offline event once when the client transitions from connected states to disconnected ones', function _test(t, done) {
			const client = connect({ reconnectPeriod: 20 })

			client.on('connect', () => {
				client.stream.end()
			})

			client.on('offline', () => {
				client.end(true, done)
			})
		})

		it('should emit offline event once when the client (at first) can NOT connect to servers', function _test(t, done) {
			// fake a port
			const client = connect({ reconnectPeriod: 20, port: 4557 })

			client.on('error', () => {})

			client.on('offline', () => {
				client.end(true, done)
			})
		})
	})

	describe('topic validations when subscribing', () => {
		it('should be ok for well-formated topics', function _test(t, done) {
			const client = connect()
			client.subscribe(
				[
					'+',
					'+/event',
					'event/+',
					'#',
					'event/#',
					'system/event/+',
					'system/+/event',
					'system/registry/event/#',
					'system/+/event/#',
					'system/registry/event/new_device',
					'system/+/+/new_device',
				],
				(err) => {
					client.end(() => {
						if (err) {
							return done(err)
						}
						done()
					})
				},
			)
		})

		it('should return an error (via callbacks) for topic #/event', function _test(t, done) {
			const client = connect()
			client.subscribe(['#/event', 'event#', 'event+'], (err) => {
				client.end(false, () => {
					if (err) {
						return done()
					}
					done(new Error('Validations do NOT work'))
				})
			})
		})

		it('should return an empty array for duplicate subs', function _test(t, done) {
			const client = connect()
			client.subscribe('event', (err, granted1) => {
				if (err) {
					return done(err)
				}
				client.subscribe('event', (err2, granted2) => {
					if (err2) {
						return done(err2)
					}
					assert.isArray(granted2)
					assert.isEmpty(granted2)
					done()
				})
			})
		})

		it('should return an error (via callbacks) for topic #/event', function _test(t, done) {
			const client = connect()
			client.subscribe('#/event', (err) => {
				client.end(() => {
					if (err) {
						return done()
					}
					done(new Error('Validations do NOT work'))
				})
			})
		})

		it('should return an error (via callbacks) for topic event#', function _test(t, done) {
			const client = connect()
			client.subscribe('event#', (err) => {
				client.end(() => {
					if (err) {
						return done()
					}
					done(new Error('Validations do NOT work'))
				})
			})
		})

		it('should return an error (via callbacks) for topic system/#/event', function _test(t, done) {
			const client = connect()
			client.subscribe('system/#/event', (err) => {
				client.end(() => {
					if (err) {
						return done()
					}
					done(new Error('Validations do NOT work'))
				})
			})
		})

		it('should return an error (via callbacks) for empty topic list', function _test(t, done) {
			const client = connect()
			client.subscribe([], (subErr) => {
				client.end((endErr) => {
					if (subErr) {
						return done(endErr)
					}
					done(new Error('Validations do NOT work'))
				})
			})
		})

		it('should return an error (via callbacks) for topic system/+/#/event', function _test(t, done) {
			const client = connect()
			client.subscribe('system/+/#/event', (subErr) => {
				client.end(true, (endErr) => {
					if (subErr) {
						return done(endErr)
					}
					done(new Error('Validations do NOT work'))
				})
			})
		})
	})

	describe('offline messages', () => {
		it('should queue message until connected', function _test(t, done) {
			const client = connect()

			client.publish('test', 'test')
			client.subscribe('test')
			client.unsubscribe('test')
			assert.strictEqual(client.queue.length, 3)

			client.once('connect', () => {
				assert.strictEqual(client.queue.length, 0)
				setTimeout(() => {
					client.end(true, done)
				}, 10)
			})
		})

		it('should not queue qos 0 messages if queueQoSZero is false', function _test(t, done) {
			const client = connect({ queueQoSZero: false })

			client.publish('test', 'test', { qos: 0 })
			assert.strictEqual(client.queue.length, 0)
			client.on('connect', () => {
				setTimeout(() => {
					client.end(true, done)
				}, 10)
			})
		})

		it('should queue qos != 0 messages', function _test(t, done) {
			const client = connect({ queueQoSZero: false })

			client.publish('test', 'test', { qos: 1 })
			client.publish('test', 'test', { qos: 2 })
			client.subscribe('test')
			client.unsubscribe('test')
			assert.strictEqual(client.queue.length, 2)
			client.on('connect', () => {
				setTimeout(() => {
					client.end(true, done)
				}, 10)
			})
		})

		it('should not interrupt messages', function _test(t, done) {
			let client = null
			let publishCount = 0
			const incomingStore = new mqtt.Store({ clean: false })
			const outgoingStore = new mqtt.Store({ clean: false })
			const server2 = serverBuilder(config.protocol, (serverClient) => {
				serverClient.on('connect', () => {
					const connack =
						version === 5 ? { reasonCode: 0 } : { returnCode: 0 }
					serverClient.connack(connack)
				})
				serverClient.on('publish', (packet) => {
					if (packet.qos !== 0) {
						serverClient.puback({ messageId: packet.messageId })
					}
					switch (publishCount++) {
						case 0:
							assert.strictEqual(
								packet.payload.toString(),
								'payload1',
							)
							break
						case 1:
							assert.strictEqual(
								packet.payload.toString(),
								'payload2',
							)
							break
						case 2:
							assert.strictEqual(
								packet.payload.toString(),
								'payload3',
							)
							break
						case 3:
							assert.strictEqual(
								packet.payload.toString(),
								'payload4',
							)
							client.end((err1) => {
								server2.close((err2) => done(err1 || err2))
							})
					}
				})
			})

			server2.listen(ports.PORTAND50, () => {
				client = connect({
					port: ports.PORTAND50,
					host: 'localhost',
					clean: false,
					clientId: 'cid1',
					reconnectPeriod: 0,
					incomingStore,
					outgoingStore,
					queueQoSZero: true,
				})
				client.on('packetreceive', (packet) => {
					if (packet.cmd === 'connack') {
						setImmediate(() => {
							client.publish('test', 'payload3', { qos: 1 })
							client.publish('test', 'payload4', { qos: 0 })
						})
					}
				})
				client.publish('test', 'payload1', { qos: 2 })
				client.publish('test', 'payload2', { qos: 2 })
			})
		})

		it('should not overtake the messages stored in the level-db-store', function _test(t, done) {
			const storePath = fs.mkdtempSync('test-store_')
			const store = levelStore(storePath)
			let client = null
			const incomingStore = store.incoming
			const outgoingStore = store.outgoing
			let publishCount = 0

			const server2 = serverBuilder(config.protocol, (serverClient) => {
				serverClient.on('connect', () => {
					const connack =
						version === 5 ? { reasonCode: 0 } : { returnCode: 0 }
					serverClient.connack(connack)
				})
				serverClient.on('publish', (packet) => {
					if (packet.qos !== 0) {
						serverClient.puback({ messageId: packet.messageId })
					}

					switch (publishCount++) {
						case 0:
							assert.strictEqual(
								packet.payload.toString(),
								'payload1',
							)
							break
						case 1:
							assert.strictEqual(
								packet.payload.toString(),
								'payload2',
							)
							break
						case 2:
							assert.strictEqual(
								packet.payload.toString(),
								'payload3',
							)

							server2.close((err) => {
								fs.rmSync(storePath, { recursive: true })
								done(err)
							})
							break
					}
				})
			})

			const clientOptions = {
				port: ports.PORTAND72,
				host: 'localhost',
				clean: false,
				clientId: 'cid1',
				reconnectPeriod: 0,
				incomingStore,
				outgoingStore,
				queueQoSZero: true,
			}

			server2.listen(ports.PORTAND72, () => {
				client = connect(clientOptions)

				client.once('close', () => {
					client.once('connect', () => {
						client.publish('test', 'payload2', { qos: 1 })
						client.publish('test', 'payload3', { qos: 1 }, () => {
							client.end(false)
						})
					})
					// reconecting
					client.reconnect(clientOptions)
				})

				// publish and close
				client.once('connect', () => {
					client.publish('test', 'payload1', {
						qos: 1,
						cbStorePut() {
							client.end(true)
						},
					})
				})
			})
		})

		it('should call cb if an outgoing QoS 0 message is not sent', function _test(t, done) {
			const client = connect({ queueQoSZero: false })
			let called = false

			client.publish('test', 'test', { qos: 0 }, () => {
				called = true
			})

			client.on('connect', () => {
				assert.isTrue(called)
				setTimeout(() => {
					client.end(true, done)
				}, 10)
			})
		})

		it('should delay ending up until all inflight messages are delivered', function _test(t, done) {
			const client = connect()
			let subscribeCalled = false

			client.on('connect', () => {
				client.subscribe('test', () => {
					subscribeCalled = true
				})
				client.publish('test', 'test', () => {
					client.end(false, () => {
						assert.strictEqual(subscribeCalled, true)
						done()
					})
				})
			})
		})

		it('wait QoS 1 publish messages', function _test(t, done) {
			const client = connect()
			let messageReceived = false

			client.on('connect', () => {
				client.subscribe('test')
				client.publish('test', 'test', { qos: 1 }, () => {
					client.end(false, () => {
						assert.strictEqual(messageReceived, true)
						done()
					})
				})
				client.on('message', () => {
					messageReceived = true
				})
			})

			server.once('client', (serverClient) => {
				serverClient.on('subscribe', () => {
					serverClient.on('publish', (packet) => {
						serverClient.publish(packet)
					})
				})
			})
		})

		it('does not wait acks when force-closing', function _test(t, done) {
			// non-running broker
			const client = connect('mqtt://localhost:8993')
			client.publish('test', 'test', { qos: 1 })
			client.end(true, done)
		})

		it('should call cb if store.put fails', function _test(t, done) {
			const store = new Store()
			store.put = (packet, cb) => {
				process.nextTick(cb, new Error('oops there is an error'))
				return store
			}
			const client = connect({
				incomingStore: store,
				outgoingStore: store,
			})
			client.publish('test', 'test', { qos: 2 }, (err) => {
				if (err) {
					client.end(true, done)
				}
			})
		})
	})

	describe('publishing', () => {
		it('should publish a message (offline)', function _test(t, done) {
			const client = connect()
			const payload = 'test'
			const topic = 'test'
			// don't wait on connect to send publish
			client.publish(topic, payload)

			server.on('client', onClient)

			function onClient(serverClient) {
				serverClient.once('connect', () => {
					server.removeListener('client', onClient)
				})

				serverClient.once('publish', (packet) => {
					assert.strictEqual(packet.topic, topic)
					assert.strictEqual(packet.payload.toString(), payload)
					assert.strictEqual(packet.qos, 0)
					assert.strictEqual(packet.retain, false)
					client.end(true, done)
				})
			}
		})

		it('should publish a message (online)', function _test(t, done) {
			const client = connect()
			const payload = 'test'
			const topic = 'test'
			// block on connect before sending publish
			client.on('connect', () => {
				client.publish(topic, payload)
			})

			server.on('client', onClient)

			function onClient(serverClient) {
				serverClient.once('connect', () => {
					server.removeListener('client', onClient)
				})

				serverClient.once('publish', (packet) => {
					assert.strictEqual(packet.topic, topic)
					assert.strictEqual(packet.payload.toString(), payload)
					assert.strictEqual(packet.qos, 0)
					assert.strictEqual(packet.retain, false)
					client.end(true, done)
				})
			}
		})

		it('should publish a message (retain, offline)', function _test(t, done) {
			const client = connect({ queueQoSZero: true })
			const payload = 'test'
			const topic = 'test'
			let called = false

			client.publish(topic, payload, { retain: true }, () => {
				called = true
			})

			server.once('client', (serverClient) => {
				serverClient.once('publish', (packet) => {
					assert.strictEqual(packet.topic, topic)
					assert.strictEqual(packet.payload.toString(), payload)
					assert.strictEqual(packet.qos, 0)
					assert.strictEqual(packet.retain, true)
					assert.strictEqual(called, true)
					client.end(true, done)
				})
			})
		})

		it('should emit a packetsend event', function _test(t, done) {
			const client = connect()
			const payload = 'test_payload'
			const topic = 'testTopic'

			client.on('packetsend', (packet) => {
				if (packet.cmd === 'publish') {
					assert.strictEqual(packet.topic, topic)
					assert.strictEqual(packet.payload.toString(), payload)
					assert.strictEqual(packet.qos, 0)
					assert.strictEqual(packet.retain, false)
					client.end(true, done)
				} else {
					done(new Error('packet.cmd was not publish!'))
				}
			})

			client.publish(topic, payload)
		})

		it('should accept options', function _test(t, done) {
			const client = connect()
			const payload = 'test'
			const topic = 'test'
			const opts: IClientPublishOptions = {
				retain: true,
				qos: 1,
			}
			let received = false

			client.once('connect', () => {
				client.publish(topic, payload, opts, (err) => {
					assert(received)
					client.end(() => {
						done(err)
					})
				})
			})

			server.once('client', (serverClient) => {
				serverClient.once('publish', (packet) => {
					assert.strictEqual(packet.topic, topic)
					assert.strictEqual(packet.payload.toString(), payload)
					assert.strictEqual(packet.qos, opts.qos, 'incorrect qos')
					assert.strictEqual(
						packet.retain,
						opts.retain,
						'incorrect ret',
					)
					assert.strictEqual(packet.dup, false, 'incorrect dup')
					received = true
				})
			})
		})

		it('should publish with the default options for an empty parameter', function _test(t, done) {
			const client = connect()
			const payload = 'test'
			const topic = 'test'
			const defaultOpts = { qos: 0, retain: false, dup: false }

			client.once('connect', () => {
				client.publish(topic, payload, {})
			})

			server.once('client', (serverClient) => {
				serverClient.once('publish', (packet) => {
					assert.strictEqual(packet.topic, topic)
					assert.strictEqual(packet.payload.toString(), payload)
					assert.strictEqual(
						packet.qos,
						defaultOpts.qos,
						'incorrect qos',
					)
					assert.strictEqual(
						packet.retain,
						defaultOpts.retain,
						'incorrect ret',
					)
					assert.strictEqual(
						packet.dup,
						defaultOpts.dup,
						'incorrect dup',
					)
					client.end(true, done)
				})
			})
		})

		it('should mark a message as duplicate when "dup" option is set', function _test(t, done) {
			const client = connect()
			const payload = 'duplicated-test'
			const topic = 'test'
			const opts: IClientPublishOptions = {
				retain: true,
				qos: 1,
				dup: true,
			}
			let received = false

			client.once('connect', () => {
				client.publish(topic, payload, opts, (err) => {
					assert(received)
					client.end(() => {
						done(err)
					})
				})
			})

			server.once('client', (serverClient) => {
				serverClient.once('publish', (packet) => {
					assert.strictEqual(packet.topic, topic)
					assert.strictEqual(packet.payload.toString(), payload)
					assert.strictEqual(packet.qos, opts.qos, 'incorrect qos')
					assert.strictEqual(
						packet.retain,
						opts.retain,
						'incorrect ret',
					)
					assert.strictEqual(packet.dup, opts.dup, 'incorrect dup')
					received = true
				})
			})
		})

		it('should fire a callback (qos 0)', function _test(t, done) {
			const client = connect()

			client.once('connect', () => {
				// callback args can be typed
				client.publish('a', 'b', (_, packet?: mqtt.Packet) => {
					assert.isUndefined(packet)
					client.end((err) => done(err))
				})
			})
		})

		it('should fire a callback (qos 1)', function _test(t, done) {
			const client = connect()
			const opts: IClientPublishOptions = { qos: 1 }

			client.once('connect', () => {
				client.publish('a', 'b', opts, (_, packet?: mqtt.Packet) => {
					assert.exists(packet)
					client.end((err) => done(err))
				})
			})
		})

		it('should fire a callback (qos 1) on error', function _test(t, done) {
			// 145 = Packet Identifier in use
			const pubackReasonCode = 145
			const pubOpts = { qos: 1 }
			let client = null

			const server2 = serverBuilder(config.protocol, (serverClient) => {
				serverClient.on('connect', () => {
					const connack =
						version === 5 ? { reasonCode: 0 } : { returnCode: 0 }
					serverClient.connack(connack)
				})
				serverClient.on('publish', (packet) => {
					if (packet.qos === 1) {
						if (version === 5) {
							serverClient.puback({
								messageId: packet.messageId,
								reasonCode: pubackReasonCode,
							})
						} else {
							serverClient.puback({ messageId: packet.messageId })
						}
					}
				})
			})

			server2.listen(ports.PORTAND72, () => {
				client = connect({
					port: ports.PORTAND72,
					host: 'localhost',
					clean: true,
					clientId: 'cid1',
					reconnectPeriod: 0,
				})

				client.once('connect', () => {
					client.publish(
						'a',
						'b',
						pubOpts,
						(err, packet?: mqtt.Packet) => {
							assert.exists(packet)
							if (version === 5) {
								assert.strictEqual(err.code, pubackReasonCode)
							} else {
								assert.ifError(err)
							}
							setImmediate(() => {
								client.end(() => {
									server2.close(done)
								})
							})
						},
					)
				})
			})
		})

		it('should fire a callback (qos 2)', function _test(t, done) {
			const client = connect()
			const opts: IClientPublishOptions = { qos: 2 }

			client.once('connect', () => {
				client.publish('a', 'b', opts, (_, packet?: mqtt.Packet) => {
					assert.exists(packet)
					client.end((err) => done(err))
				})
			})
		})

		it('should fire a callback (qos 2) on error', function _test(t, done) {
			// 145 = Packet Identifier in use
			const pubrecReasonCode = 145
			const pubOpts = { qos: 2 }
			let client = null

			const server2 = serverBuilder(config.protocol, (serverClient) => {
				serverClient.on('connect', () => {
					const connack =
						version === 5 ? { reasonCode: 0 } : { returnCode: 0 }
					serverClient.connack(connack)
				})
				serverClient.on('publish', (packet) => {
					if (packet.qos === 2) {
						if (version === 5) {
							serverClient.pubrec({
								messageId: packet.messageId,
								reasonCode: pubrecReasonCode,
							})
						} else {
							serverClient.pubrec({ messageId: packet.messageId })
						}
					}
				})
				serverClient.on('pubrel', (packet) => {
					if (!serverClient.writable) return false
					serverClient.pubcomp(packet)
				})
			})

			server2.listen(ports.PORTAND103, () => {
				client = connect({
					port: ports.PORTAND103,
					host: 'localhost',
					clean: true,
					clientId: 'cid1',
					reconnectPeriod: 0,
				})

				client.once('connect', () => {
					client.publish(
						'a',
						'b',
						pubOpts,
						(err, packet?: mqtt.Packet) => {
							assert.exists(packet)
							if (version === 5) {
								assert.strictEqual(err.code, pubrecReasonCode)
							} else {
								assert.ifError(err)
							}
							setImmediate(() => {
								client.end(true, () => {
									server2.close(done)
								})
							})
						},
					)
				})
			})
		})

		it('should support UTF-8 characters in topic', function _test(t, done) {
			const client = connect()

			client.once('connect', () => {
				client.publish('中国', 'hello', () => {
					client.end((err) => done(err))
				})
			})
		})

		it('should support UTF-8 characters in payload', function _test(t, done) {
			const client = connect()

			client.once('connect', () => {
				client.publish('hello', '中国', () => {
					client.end((err) => done(err))
				})
			})
		})

		it('should publish 10 QoS 2 and receive them', function _test(t, done) {
			const client = connect()
			let countSent = 0
			let countReceived = 0

			function publishNext() {
				client.publish('test', 'test', { qos: 2 }, (err) => {
					assert.ifError(err)
					countSent++
				})
			}

			client.on('connect', () => {
				client.subscribe('test', (err) => {
					assert.ifError(err)
					publishNext()
				})
			})

			client.on('message', () => {
				countReceived++
				if (countSent >= 10 && countReceived >= 10) {
					client.end(done)
				} else {
					publishNext()
				}
			})

			server.once('client', (serverClient) => {
				serverClient.on('offline', () => {
					client.end()
					done('error went offline... didnt see this happen')
				})

				serverClient.on('subscribe', () => {
					serverClient.on('publish', (packet) => {
						serverClient.publish(packet)
					})
				})
			})
		})

		function testQosHandleMessage(qos, done) {
			const client = connect()

			let messageEventCount = 0
			let handleMessageCount = 0

			client.handleMessage = (packet, callback) => {
				setTimeout(() => {
					handleMessageCount++
					// next message event should not emit until handleMessage completes
					assert.strictEqual(handleMessageCount, messageEventCount)
					if (handleMessageCount === 10) {
						setTimeout(() => {
							client.end(true, done)
						})
					}
					callback()
				}, 100)
			}

			client.on('message', (topic, message, packet) => {
				messageEventCount++
			})

			client.on('connect', () => {
				client.subscribe('test')
			})

			server.once('client', (serverClient) => {
				serverClient.on('offline', () => {
					client.end(true, () => {
						done('error went offline... didnt see this happen')
					})
				})

				serverClient.on('subscribe', () => {
					for (let i = 0; i < 10; i++) {
						serverClient.publish({
							messageId: i,
							topic: 'test',
							payload: `test${i}`,
							qos,
						})
					}
				})
			})
		}

		const qosTests = [0, 1, 2]
		qosTests.forEach((qos) => {
			it(`should publish 10 QoS ${qos}and receive them only when \`handleMessage\` finishes`, function _test(t, done) {
				testQosHandleMessage(qos, done)
			})
		})

		it('should not send a `puback` if the execution of `handleMessage` fails for messages with QoS `1`', function _test(t, done) {
			const client = connect()

			client.handleMessage = (packet, callback) => {
				callback(new Error('Error thrown by the application'))
			}

			const sendSpy = sinon.spy()

			client['_sendPacket'] = sendSpy

			handlePublish(
				client,
				{
					cmd: 'publish',
					messageId: Math.floor(65535 * Math.random()),
					topic: 'test',
					payload: 'test',
					qos: 1,
					dup: false,
					retain: false,
				},
				(err) => {
					assert.exists(err)
				},
			)

			assert.strictEqual(sendSpy.callCount, 0)
			client.end()
			client.on('connect', () => {
				done()
			})
		})

		it(
			'should silently ignore errors thrown by `handleMessage` and return when no callback is passed ' +
				'into `handlePublish` method',
			function _test(t, done) {
				const client = connect()

				client.handleMessage = (packet, callback) => {
					callback(new Error('Error thrown by the application'))
				}

				try {
					handlePublish(client, {
						cmd: 'publish',
						messageId: Math.floor(65535 * Math.random()),
						topic: 'test',
						payload: 'test',
						qos: 1,
						dup: false,
						retain: false,
					})
					client.end(true, done)
				} catch (err) {
					client.end(true, () => {
						done(err)
					})
				}
			},
		)

		it('should handle error with async incoming store in QoS 1 `handlePublish` method', function _test(t, done) {
			class AsyncStore extends Store {
				put(packet, cb) {
					process.nextTick(() => {
						cb(null, 'Error')
					})

					return this
				}

				close(cb) {
					cb()
				}
			}

			const store = new AsyncStore()
			const client = connect({ incomingStore: store })

			handlePublish(
				client,
				{
					cmd: 'publish',
					messageId: 1,
					topic: 'test',
					payload: 'test',
					qos: 1,
					dup: false,
					retain: false,
				},
				() => {
					client.end((err) => done(err))
				},
			)
		})

		it('should handle error with async incoming store in QoS 2 `handlePublish` method', function _test(t, done) {
			class AsyncStore extends Store {
				put(packet, cb) {
					process.nextTick(() => {
						cb(null, 'Error')
					})

					return this
				}

				del(packet, cb) {
					process.nextTick(() => {
						cb(new Error('Error'))
					})

					return this
				}

				get(packet, cb) {
					process.nextTick(() => {
						cb(null, { cmd: 'publish' })
					})
					return this
				}

				close(cb) {
					cb()
				}
			}

			const store = new AsyncStore()
			const client = connect({ incomingStore: store })

			handlePublish(
				client,
				{
					cmd: 'publish',
					dup: false,
					retain: false,
					messageId: 1,
					topic: 'test',
					payload: 'test',
					qos: 2,
				},
				() => {
					client.end((err) => done(err))
				},
			)
		})

		it('should handle error with async incoming store in QoS 2 `handlePubrel` method', function _test(t, done) {
			class AsyncStore extends Store {
				put(packet, cb) {
					process.nextTick(() => {
						cb(null, 'Error')
					})

					return this
				}

				del(packet, cb) {
					process.nextTick(() => {
						cb(new Error('Error'))
					})

					return this
				}

				get(packet, cb) {
					process.nextTick(() => {
						cb(null, { cmd: 'publish' })
					})

					return this
				}

				close(cb) {
					cb()
				}
			}

			const store = new AsyncStore()
			const client = connect({ incomingStore: store })

			handlePubrel(
				client,
				{
					cmd: 'pubrel',
					messageId: 1,
					// qos: 2,
				},
				() => {
					client.end(true, (err) => done(err))
				},
			)
		})

		it('should handle success with async incoming store in QoS 2 `handlePubrel` method', function _test(t, done) {
			let delComplete = false
			class AsyncStore extends Store {
				put(packet, cb) {
					process.nextTick(() => {
						cb(null, 'Error')
					})

					return this
				}

				del(packet, cb) {
					process.nextTick(() => {
						delComplete = true
						cb(null)
					})

					return this
				}

				get(packet, cb) {
					process.nextTick(() => {
						cb(null, { cmd: 'publish' })
					})
					return this
				}

				close(cb) {
					cb()
				}
			}

			const store = new AsyncStore()
			const client = connect({ incomingStore: store })

			handlePubrel(
				client,
				{
					cmd: 'pubrel',
					messageId: 1,
					// qos: 2,
				},
				() => {
					assert.isTrue(delComplete)
					client.end(true, done)
				},
			)
		})

		it('should not send a `pubcomp` if the execution of `handleMessage` fails for messages with QoS `2`', function _test(t, done) {
			const store = new Store()
			const client = connect({ incomingStore: store })

			const messageId = Math.floor(65535 * Math.random())
			const topic = 'testTopic'
			const payload = 'testPayload'
			const qos = 2

			client.handleMessage = (packet, callback) => {
				callback(new Error('Error thrown by the application'))
			}

			client.once('connect', () => {
				client.subscribe(topic, { qos: 2 })

				store.put(
					{
						messageId,
						topic,
						payload,
						qos,
						cmd: 'publish',
						dup: false,
						retain: false,
					},
					() => {
						const spy = sinon.spy()
						// cleans up the client
						client['_sendPacket'] = spy
						handlePubrel(
							client,
							{ cmd: 'pubrel', messageId },
							(err) => {
								assert.exists(err)
								assert.strictEqual(spy.callCount, 0)
								client.end(true, done)
							},
						)
					},
				)
			})
		})

		it(
			'should silently ignore errors thrown by `handleMessage` and return when no callback is passed ' +
				'into `handlePubrel` method',
			function _test(t, done) {
				const store = new Store()
				const client = connect({ incomingStore: store })

				const messageId = Math.floor(65535 * Math.random())
				const topic = 'test'
				const payload = 'test'
				const qos = 2

				client.handleMessage = (packet, callback) => {
					callback(new Error('Error thrown by the application'))
				}

				client.once('connect', () => {
					client.subscribe(topic, { qos: 2 })

					store.put(
						{
							messageId,
							topic,
							payload,
							qos,
							cmd: 'publish',
							dup: false,
							retain: false,
						},
						() => {
							try {
								handlePubrel(client, {
									cmd: 'pubrel',
									messageId,
								})
								client.end(true, done)
							} catch (err) {
								client.end(true, () => {
									done(err)
								})
							}
						},
					)
				})
			},
		)

		it('should keep message order', function _test(t, done) {
			let publishCount = 0
			let reconnect = false
			let client: mqtt.MqttClient
			const incomingStore = new Store({ clean: false })
			const outgoingStore = new Store({ clean: false })
			const server2 = serverBuilder(config.protocol, (serverClient) => {
				// errors are not interesting for this test
				// but they might happen on some platforms
				serverClient.on('error', () => {})

				serverClient.on('connect', (packet) => {
					const connack =
						version === 5 ? { reasonCode: 0 } : { returnCode: 0 }
					serverClient.connack(connack)
				})
				serverClient.on('publish', (packet) => {
					serverClient.puback({ messageId: packet.messageId })
					if (reconnect) {
						switch (publishCount++) {
							case 0:
								assert.strictEqual(
									packet.payload.toString(),
									'payload1',
								)
								break
							case 1:
								assert.strictEqual(
									packet.payload.toString(),
									'payload2',
								)
								break
							case 2:
								assert.strictEqual(
									packet.payload.toString(),
									'payload3',
								)
								client.end((err1) => {
									server2.close((err2) => done(err1 || err2))
								})
								break
						}
					}
				})
			})

			server2.listen(ports.PORTAND50, () => {
				client = connect({
					port: ports.PORTAND50,
					host: 'localhost',
					clean: false,
					clientId: 'cid1',
					reconnectPeriod: 0,
					incomingStore,
					outgoingStore,
				})

				client.on('connect', () => {
					if (!reconnect) {
						client.publish('topic', 'payload1', { qos: 1 })
						client.publish('topic', 'payload2', { qos: 1 })
						client.end(true)
					} else {
						client.publish('topic', 'payload3', { qos: 1 })
					}
				})
				client.on('close', () => {
					if (!reconnect) {
						client.reconnect({
							// clean: false, TODO: should we handle this?
							incomingStore,
							outgoingStore,
						})
						reconnect = true
					}
				})
			})
		})

		function testCallbackStorePutByQoS(
			qos: number,
			clean: boolean,
			expected: string[],
			done: DoneCallback,
		) {
			const client = connect({
				clean,
				clientId: 'testId',
			})

			const callbacks = []

			function cbStorePut() {
				callbacks.push('storeput')
			}

			client.on('connect', () => {
				client.publish(
					'test',
					'test',
					{ qos: qos as QoS, cbStorePut },
					(err) => {
						if (err) done(err)
						callbacks.push('publish')
						assert.deepEqual(callbacks, expected)
						client.end(true, done)
					},
				)
			})
		}

		const callbackStorePutByQoSParameters = [
			{ args: [0, true], expected: ['publish'] },
			{ args: [0, false], expected: ['publish'] },
			{ args: [1, true], expected: ['storeput', 'publish'] },
			{ args: [1, false], expected: ['storeput', 'publish'] },
			{ args: [2, true], expected: ['storeput', 'publish'] },
			{ args: [2, false], expected: ['storeput', 'publish'] },
		]

		callbackStorePutByQoSParameters.forEach((test) => {
			if (test.args[0] === 0) {
				// QoS 0
				it(`should not call cbStorePut when publishing message with QoS \`${test.args[0]}\` and clean \`${test.args[1]}\``, function _test(t, done) {
					testCallbackStorePutByQoS(
						test.args[0] as number,
						test.args[1] as boolean,
						test.expected,
						done,
					)
				})
			} else {
				// QoS 1 and 2
				it(`should call cbStorePut before publish completes when publishing message with QoS \`${test.args[0]}\` and clean \`${test.args[1]}\``, function _test(t, done) {
					testCallbackStorePutByQoS(
						test.args[0] as number,
						test.args[1] as boolean,
						test.expected,
						done,
					)
				})
			}
		})
	})

	describe('unsubscribing', () => {
		it('should send an unsubscribe packet (offline)', function _test(t, done) {
			const client = connect()
			let received = false

			client.unsubscribe('test', (err) => {
				assert.ifError(err)
				assert(received)
				client.end(done)
			})

			server.once('client', (serverClient) => {
				serverClient.once('unsubscribe', (packet) => {
					assert.include(packet.unsubscriptions, 'test')
					received = true
				})
			})
		})

		it('should send an unsubscribe packet', function _test(t, done) {
			const client = connect()
			const topic = 'topic'
			let received = false

			client.once('connect', () => {
				client.unsubscribe(topic, (err) => {
					assert.ifError(err)
					assert(received)
					client.end(done)
				})
			})

			server.once('client', (serverClient) => {
				serverClient.once('unsubscribe', (packet) => {
					assert.include(packet.unsubscriptions, topic)
					received = true
				})
			})
		})

		it('should emit a packetsend event', function _test(t, done) {
			const client = connect()
			const testTopic = 'testTopic'

			client.once('connect', () => {
				client.subscribe(testTopic)
			})

			client.on('packetsend', (packet) => {
				if (packet.cmd === 'subscribe') {
					client.end(true, done)
				}
			})
		})

		it('should emit a packetreceive event', function _test(t, done) {
			const client = connect()
			const testTopic = 'testTopic'

			client.once('connect', () => {
				client.subscribe(testTopic)
			})

			client.on('packetreceive', (packet) => {
				if (packet.cmd === 'suback') {
					client.end(true, done)
				}
			})
		})

		it('should accept an array of unsubs', function _test(t, done) {
			const client = connect()
			const topics = ['topic1', 'topic2']
			let received = false

			client.once('connect', () => {
				client.unsubscribe(topics, (err) => {
					assert.ifError(err)
					assert(received)
					client.end(done)
				})
			})

			server.once('client', (serverClient) => {
				serverClient.once('unsubscribe', (packet) => {
					assert.deepStrictEqual(packet.unsubscriptions, topics)
					received = true
				})
			})
		})

		it('should fire a callback on unsuback', function _test(t, done) {
			const client = connect()
			const topic = 'topic'

			client.once('connect', () => {
				// callback args can be typed
				client.unsubscribe(topic, (_, packet?: mqtt.Packet) => {
					assert.isUndefined(packet)
					client.end(true, done)
				})
			})

			server.once('client', (serverClient) => {
				serverClient.once('unsubscribe', (packet) => {
					serverClient.unsuback(packet)
				})
			})
		})

		it('should unsubscribe from a chinese topic', function _test(t, done) {
			const client = connect()
			const topic = '中国'

			client.once('connect', () => {
				client.unsubscribe(topic, () => {
					client.end((err) => {
						done(err)
					})
				})
			})

			server.once('client', (serverClient) => {
				serverClient.once('unsubscribe', (packet) => {
					assert.include(packet.unsubscriptions, topic)
				})
			})
		})
	})

	describe('keepalive', () => {
		let clock: sinon.SinonFakeTimers

		// eslint-disable-next-line
		beforeEach(() => {
			clock = sinon.useFakeTimers()
		})

		afterEach(() => {
			clock.restore()
		})

		it('should checkPing at keepalive interval', function _test(t, done) {
			const interval = 3
			const client = connect({ keepalive: interval })

			const spy = sinon.spy()
			client['_checkPing'] = spy

			client.once('connect', () => {
				clock.tick(interval * 1000)
				assert.strictEqual(spy.callCount, 1)

				clock.tick(interval * 1000)
				assert.strictEqual(spy.callCount, 2)

				clock.tick(interval * 1000)
				assert.strictEqual(spy.callCount, 3)

				client.end(true, done)
			})
		})

		it('should not checkPing if publishing at a higher rate than keepalive', function _test(t, done) {
			const intervalMs = 3000
			const client = connect({ keepalive: intervalMs / 1000 })

			const spy = sinon.spy()
			client['_checkPing'] = spy

			client.once('connect', () => {
				client.publish('foo', 'bar')
				clock.tick(intervalMs - 1)
				client.publish('foo', 'bar')
				clock.tick(2)

				assert.strictEqual(spy.callCount, 0)
				client.end(true, done)
			})
		})

		it('should checkPing if publishing at a higher rate than keepalive and reschedulePings===false', function _test(t, done) {
			const intervalMs = 3000
			const client = connect({
				keepalive: intervalMs / 1000,
				reschedulePings: false,
			})

			const spy = sinon.spy()
			client['_checkPing'] = spy

			client.once('connect', () => {
				client.publish('foo', 'bar')
				clock.tick(intervalMs - 1)
				client.publish('foo', 'bar')
				clock.tick(2)

				assert.strictEqual(spy.callCount, 1)
				client.end(true, done)
			})
		})
	})

	describe('pinging', () => {
		it('should set a ping timer', function _test(t, done) {
			const client = connect({ keepalive: 3 })
			client.once('connect', () => {
				assert.exists(client.pingTimer)
				client.end(true, done)
			})
		})

		it('should not set a ping timer keepalive=0', function _test(t, done) {
			const client = connect({ keepalive: 0 })
			client.on('connect', () => {
				assert.notExists(client.pingTimer)
				client.end(true, done)
			})
		})

		it(
			'should reconnect if pingresp is not sent',
			{
				timeout: 4000,
			},
			function _test(t, done) {
				const client = connect({ keepalive: 1, reconnectPeriod: 100 })

				// Fake no pingresp being send by stubbing the _handlePingresp function
				client.on('packetreceive', (packet) => {
					if (packet.cmd === 'pingresp') {
						setImmediate(() => {
							client.pingResp = false
						})
					}
				})

				client.once('connect', () => {
					client.once('connect', () => {
						client.end(true, done)
					})
				})
			},
		)

		it('should not reconnect if pingresp is successful', function _test(t, done) {
			const client = connect({ keepalive: 100 })
			client.once('close', () => {
				done(new Error('Client closed connection'))
			})
			setTimeout(() => {
				client.removeAllListeners('close')
				client.end(true, done)
			}, 1000)
		})

		it('should defer the next ping when sending a control packet', function _test(t, done) {
			const client = connect({ keepalive: 1 })

			client.once('connect', () => {
				const spy = sinon.spy()
				client['_checkPing'] = spy

				client.publish('foo', 'bar')
				setTimeout(() => {
					assert.strictEqual(spy.callCount, 0)
					client.publish('foo', 'bar')

					setTimeout(() => {
						assert.strictEqual(spy.callCount, 0)
						client.publish('foo', 'bar')

						setTimeout(() => {
							assert.strictEqual(spy.callCount, 0)
							done()
						}, 75)
					}, 75)
				}, 75)
			})
		})
	})

	describe('subscribing', () => {
		it('should send a subscribe message (offline)', function _test(t, done) {
			const client = connect()

			client.subscribe('test')

			server.once('client', (serverClient) => {
				serverClient.once('subscribe', () => {
					done()
				})
			})
		})

		it('should send a subscribe message', function _test(t, done) {
			const client = connect()
			const topic = 'test'

			client.once('connect', () => {
				client.subscribe(topic)
			})

			server.once('client', (serverClient) => {
				serverClient.once('subscribe', (packet) => {
					const result: ISubscriptionRequest = {
						topic,
						qos: 0,
					}
					if (version === 5) {
						result.nl = false
						result.rap = false
						result.rh = 0
					}
					assert.include(packet.subscriptions[0], result)
					done()
				})
			})
		})

		it('should emit a packetsend event', function _test(t, done) {
			const client = connect()
			const testTopic = 'testTopic'

			client.once('connect', () => {
				client.subscribe(testTopic)
			})

			client.on('packetsend', (packet) => {
				if (packet.cmd === 'subscribe') {
					done()
				}
			})
		})

		it('should emit a packetreceive event', function _test(t, done) {
			const client = connect()
			const testTopic = 'testTopic'

			client.once('connect', () => {
				client.subscribe(testTopic)
			})

			client.on('packetreceive', (packet) => {
				if (packet.cmd === 'suback') {
					done()
				}
			})
		})

		it('should accept an array of subscriptions', function _test(t, done) {
			const client = connect()
			const subs = ['test1', 'test2']

			client.once('connect', () => {
				client.subscribe(subs)
			})

			server.once('client', (serverClient) => {
				serverClient.once('subscribe', (packet) => {
					// i.e. [{topic: 'a', qos: 0}, {topic: 'b', qos: 0}]
					const expected = subs.map((i) => {
						const result: ISubscriptionRequest = {
							topic: i,
							qos: 0,
						}
						if (version === 5) {
							result.nl = false
							result.rap = false
							result.rh = 0
						}
						return result
					})

					assert.deepStrictEqual(packet.subscriptions, expected)
					client.end(done)
				})
			})
		})

		it('should accept a hash of subscriptions', function _test(t, done) {
			const client = connect()
			const topics: ISubscriptionMap = {
				test1: { qos: 0 },
				test2: { qos: 1 },
			}

			client.once('connect', () => {
				client.subscribe(topics)
			})

			server.once('client', (serverClient) => {
				serverClient.once('subscribe', (packet) => {
					const expected = []

					for (const k in topics) {
						if (Object.prototype.hasOwnProperty.call(topics, k)) {
							const result: ISubscriptionRequest = {
								topic: k,
								qos: topics[k].qos,
							}
							if (version === 5) {
								result.nl = false
								result.rap = false
								result.rh = 0
							}
							expected.push(result)
						}
					}

					assert.deepStrictEqual(packet.subscriptions, expected)
					client.end(done)
				})
			})
		})

		it('should accept an options parameter', function _test(t, done) {
			const client = connect()
			const topic = 'test'
			const opts: IClientSubscribeOptions = { qos: 1 }

			client.once('connect', () => {
				client.subscribe(topic, opts)
			})

			server.once('client', (serverClient) => {
				serverClient.once('subscribe', (packet) => {
					const expected: ISubscriptionRequest[] = [
						{
							topic,
							qos: 1,
						},
					]

					if (version === 5) {
						expected[0].nl = false
						expected[0].rap = false
						expected[0].rh = 0
					}

					assert.deepStrictEqual(packet.subscriptions, expected)
					done()
				})
			})
		})

		it('should subscribe with the default options for an empty options parameter', function _test(t, done) {
			const client = connect()
			const topic = 'test'
			const defaultOpts = { qos: 0 }

			client.once('connect', () => {
				client.subscribe(topic, {})
			})

			server.once('client', (serverClient) => {
				serverClient.once('subscribe', (packet) => {
					const result: ISubscriptionRequest = {
						topic,
						qos: defaultOpts.qos as QoS,
					}
					if (version === 5) {
						result.nl = false
						result.rap = false
						result.rh = 0
					}

					assert.include(packet.subscriptions[0], result)
					client.end((err) => done(err))
				})
			})
		})

		it('should fire a callback on suback', function _test(t, done) {
			const client = connect()
			const topic = 'test'

			client.once('connect', () => {
				client.subscribe(topic, { qos: 2 }, (err, granted) => {
					if (err) {
						done(err)
					} else {
						assert.exists(granted, 'granted not given')
						const expectedResult: ISubscriptionRequest = {
							topic: 'test',
							qos: 2,
						}
						if (version === 5) {
							expectedResult.nl = false
							expectedResult.rap = false
							expectedResult.rh = 0
							expectedResult.properties = undefined
						}
						assert.include(granted[0], expectedResult)
						client.end((err2) => done(err2))
					}
				})
			})
		})

		it('should fire a callback with error if disconnected (options provided)', function _test(t, done) {
			const client = connect()
			const topic = 'test'
			client.once('connect', () => {
				client.end(true, () => {
					client.subscribe(topic, { qos: 2 }, (err, granted) => {
						assert.notExists(granted, 'granted given')
						assert.exists(err, 'no error given')
						done()
					})
				})
			})
		})

		it('should fire a callback with error if disconnected (options not provided)', function _test(t, done) {
			const client = connect()
			const topic = 'test'

			client.once('connect', () => {
				client.end(true, () => {
					client.subscribe(topic, (err, granted) => {
						assert.notExists(granted, 'granted given')
						assert.exists(err, 'no error given')
						done()
					})
				})
			})
		})

		it('should subscribe with a chinese topic', function _test(t, done) {
			const client = connect()
			const topic = '中国'

			client.once('connect', () => {
				client.subscribe(topic)
			})

			server.once('client', (serverClient) => {
				serverClient.once('subscribe', (packet) => {
					const result: ISubscriptionRequest = {
						topic,
						qos: 0,
					}
					if (version === 5) {
						result.nl = false
						result.rap = false
						result.rh = 0
					}
					assert.include(packet.subscriptions[0], result)
					client.end(done)
				})
			})
		})
	})

	describe('receiving messages', () => {
		it('should fire the message event', function _test(t, done) {
			const client = connect()
			const testPacket = {
				topic: 'test',
				payload: 'message',
				retain: true,
				qos: 1,
				messageId: 5,
			}

			//
			client.subscribe(testPacket.topic)
			client.once(
				'message',
				(topic, message, packet: mqtt.IPublishPacket) => {
					assert.strictEqual(topic, testPacket.topic)
					assert.strictEqual(message.toString(), testPacket.payload)
					assert.strictEqual(packet.cmd, 'publish')
					client.end(true, done)
				},
			)

			server.once('client', (serverClient) => {
				serverClient.on('subscribe', () => {
					serverClient.publish(testPacket)
				})
			})
		})

		it('should emit a packetreceive event', function _test(t, done) {
			const client = connect()
			const testPacket = {
				topic: 'test',
				payload: 'message',
				retain: true,
				qos: 1,
				messageId: 5,
			}

			client.subscribe(testPacket.topic)
			client.on('packetreceive', (packet: mqtt.Packet) => {
				if (packet.cmd === 'publish') {
					assert.strictEqual(packet.qos, 1)
					assert.strictEqual(packet.topic, testPacket.topic)
					assert.strictEqual(
						packet.payload.toString(),
						testPacket.payload,
					)
					assert.strictEqual(packet.retain, true)
					client.end(true, done)
				}
			})

			server.once('client', (serverClient) => {
				serverClient.on('subscribe', () => {
					serverClient.publish(testPacket)
				})
			})
		})

		it('should support binary data', function _test(t, done) {
			const client = connect({ encoding: 'binary' })
			const testPacket = {
				topic: 'test',
				payload: 'message',
				retain: true,
				qos: 1,
				messageId: 5,
			}

			client.subscribe(testPacket.topic)
			client.once('message', (topic, message, packet) => {
				assert.strictEqual(topic, testPacket.topic)
				assert.instanceOf(message, Buffer)
				assert.strictEqual(message.toString(), testPacket.payload)
				assert.strictEqual(packet.cmd, 'publish')
				client.end(true, done)
			})

			server.once('client', (serverClient) => {
				serverClient.on('subscribe', () => {
					serverClient.publish(testPacket)
				})
			})
		})

		it('should emit a message event (qos=2)', function _test(t, done) {
			const client = connect()
			const testPacket = {
				topic: 'test',
				payload: 'message',
				retain: true,
				qos: 2,
				messageId: 5,
			}

			server.testPublish = testPacket

			client.subscribe(testPacket.topic)
			client.once('message', (topic, message, packet) => {
				assert.strictEqual(topic, testPacket.topic)
				assert.strictEqual(message.toString(), testPacket.payload)
				assert.strictEqual(packet.messageId, testPacket.messageId)
				assert.strictEqual(packet.qos, testPacket.qos)
				client.end(true, done)
			})

			server.once('client', (serverClient) => {
				serverClient.on('subscribe', () => {
					serverClient.publish(testPacket)
				})
			})
		})

		it('should emit a message event (qos=2) - repeated publish', function _test(t, done) {
			const client = connect()
			const testPacket = {
				topic: 'test',
				payload: 'message',
				retain: true,
				qos: 2,
				messageId: 5,
			}

			server.testPublish = testPacket

			const messageHandler = (topic, message, packet) => {
				assert.strictEqual(topic, testPacket.topic)
				assert.strictEqual(message.toString(), testPacket.payload)
				assert.strictEqual(packet.messageId, testPacket.messageId)
				assert.strictEqual(packet.qos, testPacket.qos)

				assert.strictEqual(spiedMessageHandler.callCount, 1)
				client.end(true, done)
			}

			const spiedMessageHandler = sinon.spy(messageHandler)

			client.subscribe(testPacket.topic)
			client.on('message', spiedMessageHandler)

			server.once('client', (serverClient) => {
				serverClient.on('subscribe', () => {
					serverClient.publish(testPacket)
					// twice, should be ignored
					serverClient.publish(testPacket)
				})
			})
		})

		it('should support a chinese topic', function _test(t, done) {
			const client = connect({ encoding: 'binary' })
			const testPacket = {
				topic: '国',
				payload: 'message',
				retain: true,
				qos: 1,
				messageId: 5,
			}

			client.subscribe(testPacket.topic)
			client.once('message', (topic, message, packet) => {
				assert.strictEqual(topic, testPacket.topic)
				assert.instanceOf(message, Buffer)
				assert.strictEqual(message.toString(), testPacket.payload)
				assert.strictEqual(packet.messageId, testPacket.messageId)
				assert.strictEqual(packet.qos, testPacket.qos)
				client.end(true, done)
			})

			server.once('client', (serverClient) => {
				serverClient.on('subscribe', () => {
					serverClient.publish(testPacket)
				})
			})
		})
	})

	describe('qos handling', () => {
		it('should follow qos 0 semantics (trivial)', function _test(t, done) {
			const client = connect()
			const testTopic = 'test'
			const testMessage = 'message'

			client.once('connect', () => {
				client.subscribe(testTopic, { qos: 0 }, () => {
					client.end(true, done)
				})
			})

			server.once('client', (serverClient) => {
				serverClient.once('subscribe', () => {
					serverClient.publish({
						topic: testTopic,
						payload: testMessage,
						qos: 0,
						retain: false,
					})
				})
			})
		})

		it('should follow qos 1 semantics', function _test(t, done) {
			const client = connect()
			const testTopic = 'test'
			const testMessage = 'message'
			const mid = 50

			client.once('connect', () => {
				client.subscribe(testTopic, { qos: 1 })
			})

			server.once('client', (serverClient) => {
				serverClient.once('subscribe', () => {
					serverClient.publish({
						topic: testTopic,
						payload: testMessage,
						messageId: mid,
						qos: 1,
					})
				})

				serverClient.once('puback', (packet) => {
					assert.strictEqual(packet.messageId, mid)
					client.end(done)
				})
			})
		})

		it('should follow qos 2 semantics', function _test(t, done) {
			const client = connect()
			const testTopic = 'test'
			const testMessage = 'message'
			const mid = 253
			let publishReceived = 0
			let pubrecReceived = 0
			let pubrelReceived = 0

			client.once('connect', () => {
				client.subscribe(testTopic, { qos: 2 })
			})

			client.on('packetreceive', (packet) => {
				switch (packet.cmd) {
					case 'connack':
					case 'suback':
						// expected, but not specifically part of QOS 2 semantics
						break
					case 'publish':
						assert.strictEqual(
							pubrecReceived,
							0,
							'server received pubrec before client sent',
						)
						assert.strictEqual(
							pubrelReceived,
							0,
							'server received pubrec before client sent',
						)
						publishReceived += 1
						break
					case 'pubrel':
						assert.strictEqual(
							publishReceived,
							1,
							'only 1 publish must be received before a pubrel',
						)
						assert.strictEqual(
							pubrecReceived,
							1,
							'invalid number of PUBREC messages (not only 1)',
						)
						pubrelReceived += 1
						break
					default:
						fail()
				}
			})

			server.once('client', (serverClient) => {
				serverClient.once('subscribe', () => {
					serverClient.publish({
						topic: testTopic,
						payload: testMessage,
						qos: 2,
						messageId: mid,
					})
				})

				serverClient.on('pubrec', () => {
					assert.strictEqual(
						publishReceived,
						1,
						'invalid number of PUBLISH messages received',
					)
					assert.strictEqual(
						pubrecReceived,
						0,
						'invalid number of PUBREC messages recevied',
					)
					pubrecReceived += 1
				})

				serverClient.once('pubcomp', () => {
					client.removeAllListeners()
					serverClient.removeAllListeners()
					assert.strictEqual(
						publishReceived,
						1,
						'invalid number of PUBLISH messages',
					)
					assert.strictEqual(
						pubrecReceived,
						1,
						'invalid number of PUBREC messages',
					)
					assert.strictEqual(
						pubrelReceived,
						1,
						'invalid nubmer of PUBREL messages',
					)
					client.end(true, done)
				})
			})
		})

		it('should should empty the incoming store after a qos 2 handshake is completed', function _test(t, done) {
			const client = connect()
			const testTopic = 'test'
			const testMessage = 'message'
			const mid = 253

			client.once('connect', () => {
				client.subscribe(testTopic, { qos: 2 })
			})

			client.on('packetreceive', (packet) => {
				if (packet.cmd === 'pubrel') {
					assert.strictEqual(
						client.incomingStore['_inflights'].size,
						1,
					)
				}
			})

			server.once('client', (serverClient) => {
				serverClient.once('subscribe', () => {
					serverClient.publish({
						topic: testTopic,
						payload: testMessage,
						qos: 2,
						messageId: mid,
					})
				})

				serverClient.once('pubcomp', () => {
					assert.strictEqual(
						client.incomingStore['_inflights'].size,
						0,
					)
					client.removeAllListeners()
					client.end(true, done)
				})
			})
		})

		function testMultiplePubrel(shouldSendPubcompFail, done) {
			const client = connect()
			const testTopic = 'test'
			const testMessage = 'message'
			const mid = 253
			let pubcompCount = 0
			let pubrelCount = 0
			let handleMessageCount = 0
			let emitMessageCount = 0
			const origSendPacket = client['_sendPacket']
			let shouldSendFail

			client.handleMessage = (packet, callback) => {
				handleMessageCount++
				callback()
			}

			client.on('message', () => {
				emitMessageCount++
			})

			client['_sendPacket'] = (packet, sendDone) => {
				shouldSendFail =
					packet.cmd === 'pubcomp' && shouldSendPubcompFail
				if (sendDone) {
					sendDone(
						shouldSendFail
							? new Error('testing pubcomp failure')
							: undefined,
					)
				}

				// send the mocked response
				switch (packet.cmd) {
					case 'subscribe': {
						const suback: ISubackPacket = {
							cmd: 'suback',
							messageId: packet.messageId,
							granted: [2],
						}
						handle(client, suback, (err) => {
							assert.isNotOk(err)
						})
						break
					}
					case 'pubrec':
					case 'pubcomp': {
						// for both pubrec and pubcomp, reply with pubrel, simulating the server not receiving the pubcomp
						if (packet.cmd === 'pubcomp') {
							pubcompCount++
							if (pubcompCount === 2) {
								// end the test once the client has gone through two rounds of replying to pubrel messages
								assert.strictEqual(pubrelCount, 2)
								assert.strictEqual(handleMessageCount, 1)
								assert.strictEqual(emitMessageCount, 1)
								client['_sendPacket'] = origSendPacket
								client.end(true, done)
								break
							}
						}

						// simulate the pubrel message, either in response to pubrec or to mock pubcomp failing to be received
						const pubrel: IPubrelPacket = {
							cmd: 'pubrel',
							messageId: mid,
						}
						pubrelCount++
						handle(client, pubrel, (err) => {
							if (shouldSendFail) {
								assert.exists(err)
								assert.instanceOf(err, Error)
							} else {
								assert.notExists(err)
							}
						})
						break
					}
				}
			}

			client.once('connect', () => {
				client.subscribe(testTopic, { qos: 2 })
				const publish: IPublishPacket = {
					cmd: 'publish',
					topic: testTopic,
					payload: testMessage,
					qos: 2,
					messageId: mid,
					dup: false,
					retain: false,
				}
				handle(client, publish, (err) => {
					assert.notExists(err)
				})
			})
		}

		it('handle qos 2 messages exactly once when multiple pubrel received', function _test(t, done) {
			testMultiplePubrel(false, done)
		})

		it('handle qos 2 messages exactly once when multiple pubrel received and sending pubcomp fails on client', function _test(t, done) {
			testMultiplePubrel(true, done)
		})
	})

	describe('auto reconnect', () => {
		it('should mark the client disconnecting if #end called', function _test(t, done) {
			const client = connect()

			client.end(true, (err) => {
				assert.isTrue(client.disconnecting)
				done(err)
			})
		})

		it('should reconnect after stream disconnect', function _test(t, done) {
			const client = connect()

			let tryReconnect = true

			client.on('connect', () => {
				if (tryReconnect) {
					client.stream.end()
					tryReconnect = false
				} else {
					client.end(true, done)
				}
			})
		})

		it("should emit 'reconnect' when reconnecting", function _test(t, done) {
			const client = connect()
			let tryReconnect = true
			let reconnectEvent = false

			client.on('reconnect', () => {
				reconnectEvent = true
			})

			client.on('connect', () => {
				if (tryReconnect) {
					client.stream.end()
					tryReconnect = false
				} else {
					assert.isTrue(reconnectEvent)
					client.end(true, done)
				}
			})
		})

		it("should emit 'offline' after going offline", function _test(t, done) {
			const client = connect()

			let tryReconnect = true
			let offlineEvent = false

			client.on('offline', () => {
				offlineEvent = true
			})

			client.on('connect', () => {
				if (tryReconnect) {
					client.stream.end()
					tryReconnect = false
				} else {
					assert.isTrue(offlineEvent)
					client.end(true, done)
				}
			})
		})

		it('should not reconnect if it was ended by the user', function _test(t, done) {
			const client = connect()

			client.on('connect', () => {
				client.end()
				done() // it will raise an exception if called two times
			})
		})

		it('should setup a reconnect timer on disconnect', function _test(t, done) {
			const client = connect()

			client.once('connect', () => {
				assert.notExists(client['reconnectTimer'])
				client.stream.end()
			})

			client.once('close', () => {
				assert.exists(client['reconnectTimer'])
				client.end(true, done)
			})
		})

		const reconnectPeriodTests = [
			{ period: 200 },
			{ period: 2000 },
			{ period: 4000 },
		]
		reconnectPeriodTests.forEach((test) => {
			it(
				`should allow specification of a reconnect period (${test.period}ms)`,
				{
					timeout: 10000,
				},
				function _test(t, done) {
					let end
					const reconnectSlushTime = 200
					const client = connect({ reconnectPeriod: test.period })
					let reconnect = false
					const start = Date.now()

					client.on('connect', () => {
						if (!reconnect) {
							client.stream.end()
							reconnect = true
						} else {
							end = Date.now()
							client.end(() => {
								const reconnectPeriodDuringTest = end - start
								if (
									reconnectPeriodDuringTest >=
										test.period - reconnectSlushTime &&
									reconnectPeriodDuringTest <=
										test.period + reconnectSlushTime
								) {
									// give the connection a 200 ms slush window
									done()
								} else {
									done(
										new Error(
											`Strange reconnect period: ${reconnectPeriodDuringTest}`,
										),
									)
								}
							})
						}
					})
				},
			)
		})

		it('should always cleanup successfully on reconnection', function _test(t, done) {
			const client = connect({
				host: 'this_hostname_should_not_exist',
				connectTimeout: 0,
				reconnectPeriod: 1,
			})
			// bind client.end so that when it is called it is automatically passed in the done callback
			setTimeout(() => {
				client.end.call(client, done)
			}, 50)
		})

		it('should emit connack timeout error', function _test(t, done) {
			const client = connect({
				connectTimeout: 0,
				reconnectPeriod: 5000,
			})

			client.on('error', (err) => {
				assert.equal(err.message, 'connack timeout')
				client.end(true, done)
			})
		})

		it(
			'should resend in-flight QoS 1 publish messages from the client',
			{
				timeout: 4000,
			},
			function _test(t, done) {
				const client = connect({ reconnectPeriod: 200 })
				let serverPublished = false
				let clientCalledBack = false

				server.once('client', (serverClient) => {
					serverClient.on('connect', () => {
						setImmediate(() => {
							serverClient.stream.destroy()
						})
					})

					server.once('client', (serverClientNew) => {
						serverClientNew.on('publish', () => {
							serverPublished = true
							check()
						})
					})
				})

				client.publish('hello', 'world', { qos: 1 }, () => {
					clientCalledBack = true
					check()
				})

				function check() {
					if (serverPublished && clientCalledBack) {
						client.end(true, done)
					}
				}
			},
		)

		it('should not resend in-flight publish messages if disconnecting', function _test(t, done) {
			const client = connect({ reconnectPeriod: 200 })
			let serverPublished = false
			let clientCalledBack = false
			server.once('client', (serverClient) => {
				serverClient.on('connect', () => {
					setImmediate(() => {
						serverClient.stream.destroy()
						client.end(true, (err) => {
							assert.isFalse(serverPublished)
							assert.isFalse(clientCalledBack)
							done(err)
						})
					})
				})
				server.once('client', (serverClientNew) => {
					serverClientNew.on('publish', () => {
						serverPublished = true
					})
				})
			})
			client.publish('hello', 'world', { qos: 1 }, () => {
				clientCalledBack = true
			})
		})

		it('should resend in-flight QoS 2 publish messages from the client', function _test(t, done) {
			const client = connect({ reconnectPeriod: 200 })
			let serverPublished = false
			let clientCalledBack = false

			server.once('client', (serverClient) => {
				// ignore errors
				serverClient.on('error', () => {})
				serverClient.on('publish', () => {
					setImmediate(() => {
						serverClient.stream.destroy()
					})
				})

				server.once('client', (serverClientNew) => {
					serverClientNew.on('pubrel', () => {
						serverPublished = true
						check()
					})
				})
			})

			client.publish('hello', 'world', { qos: 2 }, () => {
				clientCalledBack = true
				check()
			})

			function check() {
				if (serverPublished && clientCalledBack) {
					client.end(true, done)
				}
			}
		})

		it('should not resend in-flight QoS 1 removed publish messages from the client', function _test(t, done) {
			const client = connect({ reconnectPeriod: 200 })
			let clientCalledBack = false

			server.once('client', (serverClient) => {
				serverClient.on('connect', () => {
					setImmediate(() => {
						serverClient.stream.destroy()
					})
				})

				server.once('client', (serverClientNew) => {
					serverClientNew.on('publish', () => {
						fail()
						done()
					})
				})
			})

			client.publish('hello', 'world', { qos: 1 }, (err) => {
				clientCalledBack = true
				assert.exists(err, 'error should exist')
				assert.strictEqual(
					err.message,
					'Message removed',
					'error message is incorrect',
				)
			})
			assert.strictEqual(Object.keys(client.outgoing).length, 1)
			assert.strictEqual(client['outgoingStore']['_inflights'].size, 1)
			client.removeOutgoingMessage(client.getLastMessageId())
			assert.strictEqual(Object.keys(client.outgoing).length, 0)
			assert.strictEqual(client['outgoingStore']['_inflights'].size, 0)
			assert.isTrue(clientCalledBack)
			client.end(true, (err) => {
				done(err)
			})
		})

		it('should not resend in-flight QoS 2 removed publish messages from the client', function _test(t, done) {
			const client = connect({ reconnectPeriod: 200 })
			let clientCalledBack = false

			server.once('client', (serverClient) => {
				serverClient.on('connect', () => {
					setImmediate(() => {
						serverClient.stream.destroy()
					})
				})

				server.once('client', (serverClientNew) => {
					serverClientNew.on('publish', () => {
						fail()
						done()
					})
				})
			})

			client.publish('hello', 'world', { qos: 2 }, (err) => {
				clientCalledBack = true
				assert.strictEqual(err.message, 'Message removed')
			})
			assert.strictEqual(Object.keys(client.outgoing).length, 1)
			assert.strictEqual(client['outgoingStore']['_inflights'].size, 1)
			client.removeOutgoingMessage(client.getLastMessageId())
			assert.strictEqual(Object.keys(client.outgoing).length, 0)
			assert.strictEqual(client['outgoingStore']['_inflights'].size, 0)
			assert.isTrue(clientCalledBack)
			client.end(true, done)
		})

		it('should resubscribe when reconnecting', function _test(t, done) {
			const client = connect({ reconnectPeriod: 100 })
			let tryReconnect = true
			let reconnectEvent = false

			client.on('reconnect', () => {
				reconnectEvent = true
			})

			client.on('connect', () => {
				if (tryReconnect) {
					client.subscribe('hello', () => {
						client.stream.end()

						server.once('client', (serverClient) => {
							serverClient.on('subscribe', () => {
								client.end(done)
							})
						})
					})

					tryReconnect = false
				} else {
					assert.isTrue(reconnectEvent)
				}
			})
		})

		it('should resubscribe when clean=false and sessionPresent=false', function _test(t, done) {
			const client = connect({
				clientId: 'test',
				reconnectPeriod: 100,
				clean: false,
				protocolVersion: 4,
			})
			let tryReconnect = true
			let reconnectEvent = false

			client.on('reconnect', () => {
				reconnectEvent = true
			})

			client.on('connect', () => {
				if (tryReconnect) {
					client.subscribe('hello', () => {
						client.stream.end()

						server.once('client', (serverClient) => {
							serverClient.on('subscribe', () => {
								client.end(done)
							})
						})
					})

					tryReconnect = false
				} else {
					assert.isTrue(reconnectEvent)
				}
			})
		})

		it('should not resubscribe when reconnecting if resubscribe is disabled', function _test(t, done) {
			const client = connect({ reconnectPeriod: 100, resubscribe: false })
			let tryReconnect = true
			let reconnectEvent = false

			client.on('reconnect', () => {
				reconnectEvent = true
			})

			client.on('connect', () => {
				if (tryReconnect) {
					client.subscribe('hello', () => {
						client.stream.end()

						server.once('client', (serverClient) => {
							serverClient.on('subscribe', () => {
								fail()
							})
						})
					})

					tryReconnect = false
				} else {
					assert.isTrue(reconnectEvent)
					assert.strictEqual(
						Object.keys(client['_resubscribeTopics']).length,
						0,
					)
					client.end(true, done)
				}
			})
		})

		it('should not resubscribe when reconnecting if suback is error', function _test(t, done) {
			let tryReconnect = true
			let reconnectEvent = false
			const server2 = serverBuilder(config.protocol, (serverClient) => {
				serverClient.on('connect', (packet) => {
					const connack =
						version === 5 ? { reasonCode: 0 } : { returnCode: 0 }
					serverClient.connack(connack)
				})
				serverClient.on('subscribe', (packet) => {
					serverClient.suback({
						messageId: packet.messageId,
						granted: packet.subscriptions.map((e) => e.qos | 0x80),
					})
					serverClient.pubrel({
						messageId: Math.floor(Math.random() * 9000) + 1000,
					})
				})
			})

			server2.listen(ports.PORTAND49, () => {
				const client = connect({
					port: ports.PORTAND49,
					host: 'localhost',
					reconnectPeriod: 100,
				})

				client.on('reconnect', () => {
					reconnectEvent = true
				})

				client.on('connect', () => {
					if (tryReconnect) {
						client.subscribe('hello', () => {
							client.stream.end()

							server.once('client', (serverClient) => {
								serverClient.on('subscribe', () => {
									fail()
								})
							})
						})
						tryReconnect = false
					} else {
						assert.isTrue(reconnectEvent)
						assert.strictEqual(
							Object.keys(client['_resubscribeTopics']).length,
							0,
						)
						client.end(true, (err1) => {
							server2.close((err2) => done(err1 || err2))
						})
					}
				})
			})
		})

		it('should preserved incomingStore after disconnecting if clean is false', function _test(t, done) {
			let reconnect = false
			let client: mqtt.MqttClient
			const incomingStore = new mqtt.Store({ clean: false })
			const outgoingStore = new mqtt.Store({ clean: false })
			const server2 = serverBuilder(config.protocol, (serverClient) => {
				serverClient.on('connect', (packet) => {
					const connack =
						version === 5 ? { reasonCode: 0 } : { returnCode: 0 }
					serverClient.connack(connack)
					if (reconnect) {
						serverClient.pubrel({ messageId: 1 })
					}
				})
				serverClient.on('subscribe', (packet) => {
					serverClient.suback({
						messageId: packet.messageId,
						granted: packet.subscriptions.map((e) => e.qos),
					})
					serverClient.publish({
						topic: 'topic',
						payload: 'payload',
						qos: 2,
						messageId: 1,
						retain: false,
					})
				})
				serverClient.on('pubrec', (packet) => {
					client.end(false, () => {
						client.reconnect({
							incomingStore,
							outgoingStore,
						})
					})
				})
				serverClient.on('pubcomp', (packet) => {
					client.end(true, (err1) => {
						server2.close((err2) => done(err1 || err2))
					})
				})
			})

			server2.listen(ports.PORTAND50, () => {
				client = connect({
					port: ports.PORTAND50,
					host: 'localhost',
					clean: false,
					clientId: 'cid1',
					reconnectPeriod: 0,
					incomingStore,
					outgoingStore,
				})

				client.on('connect', () => {
					if (!reconnect) {
						client.subscribe('test', { qos: 2 }, () => {})
						reconnect = true
					}
				})
				client.on('message', (topic, message) => {
					assert.strictEqual(topic, 'topic')
					assert.strictEqual(message.toString(), 'payload')
				})
			})
		})

		it('should clear outgoing if close from server', function _test(t, done) {
			let reconnect = false
			let client: mqtt.MqttClient
			const server2 = serverBuilder(config.protocol, (serverClient) => {
				serverClient.on('connect', (packet) => {
					const connack =
						version === 5 ? { reasonCode: 0 } : { returnCode: 0 }
					serverClient.connack(connack)
				})
				serverClient.on('subscribe', (packet) => {
					if (reconnect) {
						serverClient.suback({
							messageId: packet.messageId,
							granted: packet.subscriptions.map((e) => e.qos),
						})
					} else {
						serverClient.destroy()
					}
				})
			})

			server2.listen(ports.PORTAND50, () => {
				client = connect({
					port: ports.PORTAND50,
					host: 'localhost',
					clean: true,
					clientId: 'cid1',
					keepalive: 1,
					reconnectPeriod: 0,
				})

				client.on('connect', () => {
					client.subscribe('test', { qos: 2 }, (e) => {
						if (!e) {
							client.end()
						}
					})
				})

				client.on('close', () => {
					if (reconnect) {
						server2.close((err) => done(err))
					} else {
						assert.strictEqual(
							Object.keys(client.outgoing).length,
							0,
						)
						reconnect = true
						client.reconnect()
					}
				})
			})
		})

		it('should resend in-flight QoS 1 publish messages from the client if clean is false', function _test(t, done) {
			let reconnect = false
			let client: mqtt.MqttClient
			const incomingStore = new mqtt.Store({ clean: false })
			const outgoingStore = new mqtt.Store({ clean: false })
			const server2 = serverBuilder(config.protocol, (serverClient) => {
				serverClient.on('connect', (packet) => {
					const connack =
						version === 5 ? { reasonCode: 0 } : { returnCode: 0 }
					serverClient.connack(connack)
				})
				serverClient.on('publish', (packet) => {
					if (reconnect) {
						client.end(true, (err1) => {
							server2.close((err2) => done(err1 || err2))
						})
					} else {
						client.end(true, () => {
							client.reconnect({
								incomingStore,
								outgoingStore,
							})
							reconnect = true
						})
					}
				})
			})

			server2.listen(ports.PORTAND50, () => {
				client = connect({
					port: ports.PORTAND50,
					host: 'localhost',
					clean: false,
					clientId: 'cid1',
					reconnectPeriod: 0,
					incomingStore,
					outgoingStore,
				})

				client.on('connect', () => {
					if (!reconnect) {
						client.publish('topic', 'payload', { qos: 1 })
					}
				})
				client.on('error', () => {})
			})
		})

		it('should resend in-flight QoS 2 publish messages from the client if clean is false', function _test(t, done) {
			let reconnect = false
			let client: mqtt.MqttClient
			const incomingStore = new mqtt.Store({ clean: false })
			const outgoingStore = new mqtt.Store({ clean: false })
			const server2 = serverBuilder(config.protocol, (serverClient) => {
				serverClient.on('connect', (packet) => {
					const connack =
						version === 5 ? { reasonCode: 0 } : { returnCode: 0 }
					serverClient.connack(connack)
				})
				serverClient.on('publish', (packet) => {
					if (reconnect) {
						client.end(true, (err1) => {
							server2.close((err2) => done(err1 || err2))
						})
					} else {
						client.end(true, () => {
							client.reconnect({
								incomingStore,
								outgoingStore,
							})
							reconnect = true
						})
					}
				})
			})

			server2.listen(ports.PORTAND50, () => {
				client = connect({
					port: ports.PORTAND50,
					host: 'localhost',
					clean: false,
					clientId: 'cid1',
					reconnectPeriod: 0,
					incomingStore,
					outgoingStore,
				})

				client.on('connect', () => {
					if (!reconnect) {
						client.publish('topic', 'payload', { qos: 2 })
					}
				})
				client.on('error', () => {})
			})
		})

		it('should resend in-flight QoS 2 pubrel messages from the client if clean is false', function _test(t, done) {
			let reconnect = false
			let client: mqtt.MqttClient
			const incomingStore = new mqtt.Store({ clean: false })
			const outgoingStore = new mqtt.Store({ clean: false })
			const server2 = serverBuilder(config.protocol, (serverClient) => {
				serverClient.on('connect', (packet) => {
					const connack =
						version === 5 ? { reasonCode: 0 } : { returnCode: 0 }
					serverClient.connack(connack)
				})
				serverClient.on('publish', (packet) => {
					if (!reconnect) {
						serverClient.pubrec({ messageId: packet.messageId })
					}
				})
				serverClient.on('pubrel', (packet) => {
					if (reconnect) {
						serverClient.pubcomp({ messageId: packet.messageId })
					} else {
						client.end(true, () => {
							client.reconnect({
								incomingStore,
								outgoingStore,
							})
							reconnect = true
						})
					}
				})
			})

			server2.listen(ports.PORTAND50, () => {
				client = connect({
					port: ports.PORTAND50,
					host: 'localhost',
					clean: false,
					clientId: 'cid1',
					reconnectPeriod: 0,
					incomingStore,
					outgoingStore,
				})

				client.on('connect', () => {
					if (!reconnect) {
						client.publish(
							'topic',
							'payload',
							{ qos: 2 },
							(err) => {
								assert(reconnect)
								assert.ifError(err)
								client.end(true, (err1) => {
									server2.close((err2) => done(err1 || err2))
								})
							},
						)
					}
				})
				client.on('error', () => {})
			})
		})

		it('should resend in-flight publish messages by published order', function _test(t, done) {
			let publishCount = 0
			let reconnect = false
			let disconnectOnce = true
			let client: mqtt.MqttClient
			const incomingStore = new mqtt.Store({ clean: false })
			const outgoingStore = new mqtt.Store({ clean: false })
			const server2 = serverBuilder(config.protocol, (serverClient) => {
				// errors are not interesting for this test
				// but they might happen on some platforms
				serverClient.on('error', () => {})

				serverClient.on('connect', (packet) => {
					const connack =
						version === 5 ? { reasonCode: 0 } : { returnCode: 0 }
					serverClient.connack(connack)
				})
				serverClient.on('publish', (packet) => {
					serverClient.puback({ messageId: packet.messageId })
					if (reconnect) {
						switch (publishCount++) {
							case 0:
								assert.strictEqual(
									packet.payload.toString(),
									'payload1',
								)
								break
							case 1:
								assert.strictEqual(
									packet.payload.toString(),
									'payload2',
								)
								break
							case 2:
								assert.strictEqual(
									packet.payload.toString(),
									'payload3',
								)
								client.end(true, (err1) => {
									server2.close((err2) => done(err1 || err2))
								})
								break
						}
					} else if (disconnectOnce) {
						client.end(true, () => {
							reconnect = true
							client.reconnect({
								incomingStore,
								outgoingStore,
							})
						})
						disconnectOnce = false
					}
				})
			})

			server2.listen(ports.PORTAND50, () => {
				client = connect({
					port: ports.PORTAND50,
					host: 'localhost',
					clean: false,
					clientId: 'cid1',
					reconnectPeriod: 0,
					incomingStore,
					outgoingStore,
				})

				client['nextId'] = 65535

				client.on('connect', () => {
					if (!reconnect) {
						client.publish('topic', 'payload1', { qos: 1 })
						client.publish('topic', 'payload2', { qos: 1 })
						client.publish('topic', 'payload3', { qos: 1 })
					}
				})
				client.on('error', () => {})
			})
		})

		it('should be able to pub/sub if reconnect() is called at close handler', function _test(t, done) {
			const client = connect({ reconnectPeriod: 0 })
			let tryReconnect = true
			let reconnectEvent = false

			client.on('close', () => {
				if (tryReconnect) {
					tryReconnect = false
					client.reconnect()
				} else {
					assert.isTrue(reconnectEvent)
					done()
				}
			})

			client.on('reconnect', () => {
				reconnectEvent = true
			})

			client.on('connect', () => {
				if (tryReconnect) {
					client.end()
				} else {
					client.subscribe('hello', () => {
						client.end()
					})
				}
			})
		})

		it('should be able to pub/sub if reconnect() is called at out of close handler', function _test(t, done) {
			const client = connect({ reconnectPeriod: 0 })
			let tryReconnect = true
			let reconnectEvent = false

			client.on('close', () => {
				if (tryReconnect) {
					tryReconnect = false
					setTimeout(() => {
						client.reconnect()
					}, 100)
				} else {
					assert.isTrue(reconnectEvent)
					done()
				}
			})

			client.on('reconnect', () => {
				reconnectEvent = true
			})

			client.on('connect', () => {
				if (tryReconnect) {
					client.end()
				} else {
					client.subscribe('hello', () => {
						client.end()
					})
				}
			})
		})

		describe('with alternate server client', () => {
			let cachedClientListeners
			const connack =
				version === 5 ? { reasonCode: 0 } : { returnCode: 0 }

			beforeEach(() => {
				cachedClientListeners = server.listeners('client')
				server.removeAllListeners('client')
			})

			afterEach(() => {
				server.removeAllListeners('client')
				cachedClientListeners.forEach((listener) => {
					server.on('client', listener)
				})
			})

			it('should resubscribe even if disconnect is before suback', function _test(t, done) {
				const client = connect({ reconnectPeriod: 100, ...config })
				let subscribeCount = 0
				let connectCount = 0

				server.on('client', (serverClient) => {
					serverClient.on('connect', () => {
						connectCount++
						serverClient.connack(connack)
					})

					serverClient.on('subscribe', () => {
						subscribeCount++

						// disconnect before sending the suback on the first subscribe
						if (subscribeCount === 1) {
							client.stream.end()
						}

						// after the second connection, confirm that the only two
						// subscribes have taken place, then cleanup and exit
						if (connectCount >= 2) {
							assert.strictEqual(subscribeCount, 2)
							client.end(true, done)
						}
					})
				})

				client.subscribe('hello')
			})

			it('should resubscribe exactly once', function _test(t, done) {
				const client = connect({ reconnectPeriod: 100, ...config })
				let subscribeCount = 0

				server.on('client', (serverClient) => {
					serverClient.on('connect', () => {
						serverClient.connack(connack)
					})

					serverClient.on('subscribe', () => {
						subscribeCount++

						// disconnect before sending the suback on the first subscribe
						if (subscribeCount === 1) {
							client.stream.end()
						}

						// after the second connection, only two subs
						// subscribes have taken place, then cleanup and exit
						if (subscribeCount === 2) {
							client.end(true, done)
						}
					})
				})

				client.subscribe('hello')
			})
		})
	})

	describe('message id to subscription topic mapping', () => {
		it('should not create a mapping if resubscribe is disabled', function _test(t, done) {
			const client = connect({ resubscribe: false })
			client.subscribe('test1')
			client.subscribe('test2')
			assert.strictEqual(Object.keys(client.messageIdToTopic).length, 0)
			client.end(true, done)
		})

		it('should create a mapping for each subscribe call', function _test(t, done) {
			const client = connect()
			client.subscribe('test1')
			assert.strictEqual(Object.keys(client.messageIdToTopic).length, 1)
			client.subscribe('test2')
			assert.strictEqual(Object.keys(client.messageIdToTopic).length, 2)

			client.subscribe(['test3', 'test4'])
			assert.strictEqual(Object.keys(client.messageIdToTopic).length, 3)
			client.subscribe(['test5', 'test6'])
			assert.strictEqual(Object.keys(client.messageIdToTopic).length, 4)

			client.end(true, done)
		})

		it('should remove the mapping after suback', function _test(t, done) {
			const client = connect()
			client.once('connect', () => {
				client.subscribe('test1', { qos: 2 }, () => {
					assert.strictEqual(
						Object.keys(client.messageIdToTopic).length,
						0,
					)

					client.subscribe(['test2', 'test3'], { qos: 2 }, () => {
						assert.strictEqual(
							Object.keys(client.messageIdToTopic).length,
							0,
						)
						client.end(done)
					})
				})
			})
		})
	})
}