MF-1197 - Add MQTT adapter tests (#1622)

* MF-1197 - add mqtt tests Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - add test cases Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - refactor tests Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - Fix test names.Add const Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - Add mocks. Add publish test Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - Add buffer to logger Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - Add redis mock.Change logger error Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - Add new test cases Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - Fix session fields Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - Fix bad logs. Fix tests Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - Add new test case.Fix names. Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - Fix test name Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - Refactoring tests Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - Wrap errors Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - Wrap errors. Fix logs level Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - Wrap errors. Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - Fix var names Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-888 - Add clientID err check.Refactor tests Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - Fix info and err names Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - Remove redundant log and channel parts check Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - Revert channel parts check Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - Add authorize test case Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - Remove unused var Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - Change var name Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 -Add missing test case.Change var name Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 -Add err case. Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 -Change var name Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - Use logMsg for all logs Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - Use logs instead of errors Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - Use redis mock Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - Return interface in constructor Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - Add missing test cases. Create consts Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - Add global vars Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - Refactor code Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - Remove unused var Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - Remove unnecessary var Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - Use created session client Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - Refactor vars Signed-off-by: zzokki81 <zoran.rebic@outlook.com> * MF-1197 - Separate constant Signed-off-by: zzokki81 <zoran.rebic@outlook.com> Signed-off-by: zzokki81 <zoran.rebic@outlook.com>
2025-04-24 13:48:49 +08:00 · 2022-11-21 14:40:19 +01:00 · 2022-11-21 14:40:19 +01:00 · 933b5dedce
commit 933b5dedce
parent 677f3c70b0
6 changed files with 530 additions and 39 deletions
--- a/mqtt/handler.go
+++ b/mqtt/handler.go
@ -5,6 +5,7 @@ package mqtt

 import (
 	"context"
+	"fmt"
 	"net/url"
 	"regexp"
 	"strings"
@ -22,15 +23,32 @@ var _ session.Handler = (*handler)(nil)

 const protocol = "mqtt"

+const (
+	LogInfoSubscribed                  = "subscribed with client_id %s to topics %s"
+	LogInfoUnsubscribed                = "unsubscribed client_id %s from topics %s"
+	LogInfoConnected                   = "connected with client_id %s"
+	LogInfoDisconnected                = "disconnected client_id %s and username %s"
+	LogInfoPublished                   = "published with client_id %s to the topic %s"
+	LogErrFailedConnect                = "failed to connect: "
+	LogErrFailedSubscribe              = "failed to subscribe: "
+	LogErrFailedUnsubscribe            = "failed to unsubscribe: "
+	LogErrFailedPublish                = "failed to publish: "
+	LogErrFailedDisconnect             = "failed to disconnect: "
+	LogErrFailedPublishDisconnectEvent = "failed to publish disconnect event: "
+	logErrFailedParseSubtopic          = "failed to parse subtopic: "
+	LogErrFailedPublishConnectEvent    = "failed to publish connect event: "
+	LogErrFailedPublishToMsgBroker     = "failed to publish to mainflux message broker: "
+)
+
 var (
-	channelRegExp        = regexp.MustCompile(`^\/?channels\/([\w\-]+)\/messages(\/[^?]*)?(\?.*)?$`)
-	errMalformedTopic    = errors.New("malformed topic")
-	errMalformedData     = errors.New("malformed request data")
-	errMalformedSubtopic = errors.New("malformed subtopic")
-	errNilClient         = errors.New("using nil client")
-	errInvalidConnect    = errors.New("CONNECT request with invalid username or client ID")
-	errNilTopicPub       = errors.New("PUBLISH to nil topic")
-	errNilTopicSub       = errors.New("SUB to nil topic")
+	channelRegExp           = regexp.MustCompile(`^\/?channels\/([\w\-]+)\/messages(\/[^?]*)?(\?.*)?$`)
+	ErrMalformedSubtopic    = errors.New("malformed subtopic")
+	ErrClientNotInitialized = errors.New("client is not initialized")
+	ErrMalformedTopic       = errors.New("malformed topic")
+	ErrMissingClientID      = errors.New("client_id not found")
+	ErrMissingTopicPub      = errors.New("failed to publish due to missing topic")
+	ErrMissingTopicSub      = errors.New("failed to subscribe due to missing topic")
+	ErrAuthentication       = errors.New("failed to perform authentication over the entity")
 )

 // Event implements events.Event interface
@ -56,7 +74,11 @@ func NewHandler(publishers []messaging.Publisher, es redis.EventStore,
 // prior forwarding to the MQTT broker
 func (h *handler) AuthConnect(c *session.Client) error {
 	if c == nil {
-		return errInvalidConnect
+		return ErrClientNotInitialized
+	}
+
+	if c.ID == "" {
+		return ErrMissingClientID
 	}

 	thid, err := h.auth.Identify(context.Background(), string(c.Password))
@ -69,7 +91,7 @@ func (h *handler) AuthConnect(c *session.Client) error {
 	}

 	if err := h.es.Connect(c.Username); err != nil {
-		h.logger.Warn("Failed to publish connect event: " + err.Error())
+		h.logger.Error(LogErrFailedPublishConnectEvent + err.Error())
 	}

 	return nil
@ -79,10 +101,10 @@ func (h *handler) AuthConnect(c *session.Client) error {
 // prior forwarding to the MQTT broker
 func (h *handler) AuthPublish(c *session.Client, topic *string, payload *[]byte) error {
 	if c == nil {
-		return errNilClient
+		return ErrClientNotInitialized
 	}
 	if topic == nil {
-		return errNilTopicPub
+		return ErrMissingTopicPub
 	}

 	return h.authAccess(c.Username, *topic)
@ -92,10 +114,10 @@ func (h *handler) AuthPublish(c *session.Client, topic *string, payload *[]byte)
 // prior forwarding to the MQTT broker
 func (h *handler) AuthSubscribe(c *session.Client, topics *[]string) error {
 	if c == nil {
-		return errNilClient
+		return ErrClientNotInitialized
 	}
 	if topics == nil || *topics == nil {
-		return errNilTopicSub
+		return ErrMissingTopicSub
 	}

 	for _, v := range *topics {
@ -111,25 +133,25 @@ func (h *handler) AuthSubscribe(c *session.Client, topics *[]string) error {
 // Connect - after client successfully connected
 func (h *handler) Connect(c *session.Client) {
 	if c == nil {
-		h.logger.Error("Nil client connect")
+		h.logger.Error(LogErrFailedConnect + (ErrClientNotInitialized).Error())
 		return
 	}
-	h.logger.Info("Connect - client with ID: " + c.ID)
+	h.logger.Info(fmt.Sprintf(LogInfoConnected, c.ID))
 }

 // Publish - after client successfully published
 func (h *handler) Publish(c *session.Client, topic *string, payload *[]byte) {
 	if c == nil {
-		h.logger.Error("Nil client publish")
+		h.logger.Error(LogErrFailedPublish + ErrClientNotInitialized.Error())
 		return
 	}
-	h.logger.Info("Publish - client ID " + c.ID + " to the topic: " + *topic)
+	h.logger.Info(fmt.Sprintf(LogInfoPublished, c.ID, *topic))
 	// Topics are in the format:
 	// channels/<channel_id>/messages/<subtopic>/.../ct/<content_type>

 	channelParts := channelRegExp.FindStringSubmatch(*topic)
-	if len(channelParts) < 1 {
-		h.logger.Info("Error in mqtt publish %s" + errMalformedData.Error())
+	if len(channelParts) < 2 {
+		h.logger.Error(LogErrFailedPublish + (ErrMalformedTopic).Error())
 		return
 	}

@ -138,7 +160,7 @@ func (h *handler) Publish(c *session.Client, topic *string, payload *[]byte) {

 	subtopic, err := parseSubtopic(subtopic)
 	if err != nil {
-		h.logger.Info("Error parsing subtopic: " + err.Error())
+		h.logger.Error(logErrFailedParseSubtopic + err.Error())
 		return
 	}

@ -153,7 +175,7 @@ func (h *handler) Publish(c *session.Client, topic *string, payload *[]byte) {

 	for _, pub := range h.publishers {
 		if err := pub.Publish(msg.Channel, msg); err != nil {
-			h.logger.Info("Error publishing to Mainflux " + err.Error())
+			h.logger.Error(LogErrFailedPublishToMsgBroker + err.Error())
 		}
 	}
 }
@ -161,30 +183,30 @@ func (h *handler) Publish(c *session.Client, topic *string, payload *[]byte) {
 // Subscribe - after client successfully subscribed
 func (h *handler) Subscribe(c *session.Client, topics *[]string) {
 	if c == nil {
-		h.logger.Error("Nil client subscribe")
+		h.logger.Error(LogErrFailedSubscribe + (ErrClientNotInitialized).Error())
 		return
 	}
-	h.logger.Info("Subscribe - client ID: " + c.ID + ", to topics: " + strings.Join(*topics, ","))
+	h.logger.Info(fmt.Sprintf(LogInfoSubscribed, c.ID, strings.Join(*topics, ",")))
 }

 // Unsubscribe - after client unsubscribed
 func (h *handler) Unsubscribe(c *session.Client, topics *[]string) {
 	if c == nil {
-		h.logger.Error("Nil client unsubscribe")
+		h.logger.Error(LogErrFailedUnsubscribe + (ErrClientNotInitialized).Error())
 		return
 	}
-	h.logger.Info("Unsubscribe - client ID: " + c.ID + ", form topics: " + strings.Join(*topics, ","))
+	h.logger.Info(fmt.Sprintf(LogInfoUnsubscribed, c.ID, strings.Join(*topics, ",")))
 }

 // Disconnect - connection with broker or client lost
 func (h *handler) Disconnect(c *session.Client) {
 	if c == nil {
-		h.logger.Error("Nil client disconnect")
+		h.logger.Error(LogErrFailedDisconnect + (ErrClientNotInitialized).Error())
 		return
 	}
-	h.logger.Info("Disconnect - Client with ID: " + c.ID + " and username " + c.Username + " disconnected")
+	h.logger.Error(fmt.Sprintf(LogInfoDisconnected, c.ID, c.Username))
 	if err := h.es.Disconnect(c.Username); err != nil {
-		h.logger.Warn("Failed to publish disconnect event: " + err.Error())
+		h.logger.Error(LogErrFailedPublishDisconnectEvent + err.Error())
 	}
 }

@ -192,13 +214,12 @@ func (h *handler) authAccess(username string, topic string) error {
 	// Topics are in the format:
 	// channels/<channel_id>/messages/<subtopic>/.../ct/<content_type>
 	if !channelRegExp.Match([]byte(topic)) {
-		h.logger.Info("Malformed topic: " + topic)
-		return errMalformedTopic
+		return ErrMalformedTopic
 	}

 	channelParts := channelRegExp.FindStringSubmatch(topic)
 	if len(channelParts) < 1 {
-		return errMalformedData
+		return ErrMalformedTopic
 	}

 	chanID := channelParts[1]
@ -212,7 +233,7 @@ func parseSubtopic(subtopic string) (string, error) {

 	subtopic, err := url.QueryUnescape(subtopic)
 	if err != nil {
-		return "", errMalformedSubtopic
+		return "", ErrMalformedSubtopic
 	}
 	subtopic = strings.Replace(subtopic, "/", ".", -1)

@ -224,7 +245,7 @@ func parseSubtopic(subtopic string) (string, error) {
 		}

 		if len(elem) > 1 && (strings.Contains(elem, "*") || strings.Contains(elem, ">")) {
-			return "", errMalformedSubtopic
+			return "", ErrMalformedSubtopic
 		}

 		filteredElems = append(filteredElems, elem)
--- a/mqtt/handler_test.go
+++ b/mqtt/handler_test.go
@ -0,0 +1,396 @@
+package mqtt_test
+
+import (
+	"bytes"
+	"fmt"
+	"log"
+	"testing"
+
+	"github.com/mainflux/mainflux/logger"
+	"github.com/mainflux/mainflux/mqtt"
+	"github.com/mainflux/mainflux/mqtt/mocks"
+	"github.com/mainflux/mainflux/pkg/errors"
+	"github.com/mainflux/mainflux/pkg/messaging"
+	"github.com/mainflux/mproxy/pkg/session"
+	"github.com/stretchr/testify/assert"
+)
+
+const (
+	thingID               = "513d02d2-16c1-4f23-98be-9e12f8fee898"
+	chanID                = "123e4567-e89b-12d3-a456-000000000001"
+	invalidID             = "invalidID"
+	clientID              = "clientID"
+	password              = "password"
+	subtopic              = "testSubtopic"
+	invalidChannelIDTopic = "channels/**/messages"
+)
+
+var (
+	topicMsg            = "channels/%s/messages"
+	topic               = fmt.Sprintf(topicMsg, chanID)
+	invalidTopic        = "invalidTopic"
+	payload             = []byte("[{'n':'test-name', 'v': 1.2}]")
+	topics              = []string{topic}
+	invalidTopics       = []string{invalidTopic}
+	invalidChanIDTopics = []string{fmt.Sprintf(topicMsg, invalidTopic)}
+	//Test log messages for cases the handler does not provide a return value.
+	logBuffer     = bytes.Buffer{}
+	sessionClient = session.Client{
+		ID:       clientID,
+		Username: thingID,
+		Password: []byte(password),
+	}
+	invalidThingSessionClient = session.Client{
+		ID:       clientID,
+		Username: invalidID,
+		Password: []byte(password),
+	}
+)
+
+func TestAuthConnect(t *testing.T) {
+	handler := newHandler()
+
+	cases := []struct {
+		desc    string
+		err     error
+		session *session.Client
+	}{
+		{
+			desc:    "connect without active session",
+			err:     mqtt.ErrClientNotInitialized,
+			session: nil,
+		},
+		{
+			desc: "connect without clientID",
+			err:  mqtt.ErrMissingClientID,
+			session: &session.Client{
+				ID:       "",
+				Username: thingID,
+				Password: []byte(password),
+			},
+		},
+		{
+			desc: "connect with invalid password",
+			err:  errors.ErrAuthentication,
+			session: &session.Client{
+				ID:       clientID,
+				Username: thingID,
+				Password: []byte(""),
+			},
+		},
+		{
+			desc:    "connect with valid password and invalid username",
+			err:     errors.ErrAuthentication,
+			session: &invalidThingSessionClient,
+		},
+		{
+			desc:    "connect with valid username and password",
+			err:     nil,
+			session: &sessionClient,
+		},
+	}
+
+	for _, tc := range cases {
+		err := handler.AuthConnect(tc.session)
+		assert.True(t, errors.Contains(err, tc.err), fmt.Sprintf("%s: expected %s got %s\n", tc.desc, tc.err, err))
+	}
+}
+
+func TestAuthPublish(t *testing.T) {
+	handler := newHandler()
+
+	cases := []struct {
+		desc    string
+		client  *session.Client
+		err     error
+		topic   *string
+		payload []byte
+	}{
+		{
+			desc:    "publish with inactive client",
+			client:  nil,
+			err:     mqtt.ErrClientNotInitialized,
+			topic:   &topic,
+			payload: payload,
+		},
+		{
+			desc:    "publish without topic",
+			client:  &sessionClient,
+			err:     mqtt.ErrMissingTopicPub,
+			topic:   nil,
+			payload: payload,
+		},
+		{
+			desc:    "publish with malformed topic",
+			client:  &sessionClient,
+			err:     mqtt.ErrMalformedTopic,
+			topic:   &invalidTopic,
+			payload: payload,
+		},
+		{
+			desc:    "publish successfully",
+			client:  &sessionClient,
+			err:     nil,
+			topic:   &topic,
+			payload: payload,
+		},
+	}
+
+	for _, tc := range cases {
+		err := handler.AuthPublish(tc.client, tc.topic, &tc.payload)
+		assert.True(t, errors.Contains(err, tc.err), fmt.Sprintf("%s: expected %s got %s\n", tc.desc, tc.err, err))
+	}
+}
+
+func TestAuthSubscribe(t *testing.T) {
+	handler := newHandler()
+
+	cases := []struct {
+		desc   string
+		client *session.Client
+		err    error
+		topic  *[]string
+	}{
+		{
+			desc:   "subscribe without active session",
+			client: nil,
+			err:    mqtt.ErrClientNotInitialized,
+			topic:  &topics,
+		},
+		{
+			desc:   "subscribe without topics",
+			client: &sessionClient,
+			err:    mqtt.ErrMissingTopicSub,
+			topic:  nil,
+		},
+		{
+			desc:   "subscribe with invalid topics",
+			client: &sessionClient,
+			err:    mqtt.ErrMalformedTopic,
+			topic:  &invalidTopics,
+		},
+		{
+			desc:   "subscribe with invalid channel ID",
+			client: &sessionClient,
+			err:    mqtt.ErrAuthentication,
+			topic:  &invalidChanIDTopics,
+		},
+		{
+			desc:   "subscribe with invalid thing ID",
+			client: &invalidThingSessionClient,
+			err:    mqtt.ErrAuthentication,
+			topic:  &topics,
+		},
+		{
+			desc:   "subscribe with active session and valid topics",
+			client: &sessionClient,
+			err:    nil,
+			topic:  &topics,
+		},
+	}
+
+	for _, tc := range cases {
+		err := handler.AuthSubscribe(tc.client, tc.topic)
+		assert.True(t, errors.Contains(err, tc.err), fmt.Sprintf("%s: expected %s got %s\n", tc.desc, tc.err, err))
+	}
+}
+
+func TestConnect(t *testing.T) {
+	handler := newHandler()
+	logBuffer.Reset()
+
+	cases := []struct {
+		desc   string
+		client *session.Client
+		logMsg string
+	}{
+		{
+			desc:   "connect without active session",
+			client: nil,
+			logMsg: mqtt.LogErrFailedConnect + mqtt.ErrClientNotInitialized.Error(),
+		},
+		{
+			desc:   "connect with active session",
+			client: &sessionClient,
+			logMsg: fmt.Sprintf(mqtt.LogInfoConnected, clientID),
+		},
+	}
+
+	for _, tc := range cases {
+		handler.Connect(tc.client)
+		assert.Contains(t, logBuffer.String(), tc.logMsg)
+	}
+}
+
+func TestPublish(t *testing.T) {
+	handler := newHandler()
+	logBuffer.Reset()
+
+	malformedSubtopics := topic + "/" + subtopic + "%"
+	wrongCharSubtopics := topic + "/" + subtopic + ">"
+	validSubtopic := topic + "/" + subtopic
+
+	cases := []struct {
+		desc    string
+		client  *session.Client
+		topic   string
+		payload []byte
+		logMsg  string
+	}{
+		{
+			desc:    "publish without active session",
+			client:  nil,
+			topic:   topic,
+			payload: payload,
+			logMsg:  mqtt.ErrClientNotInitialized.Error(),
+		},
+		{
+			desc:    "publish with invalid topic",
+			client:  &sessionClient,
+			topic:   invalidTopic,
+			payload: payload,
+			logMsg:  fmt.Sprintf(mqtt.LogInfoPublished, clientID, invalidTopic),
+		},
+		{
+			desc:    "publish with invalid channel ID",
+			client:  &sessionClient,
+			topic:   invalidChannelIDTopic,
+			payload: payload,
+			logMsg:  mqtt.LogErrFailedPublish + mqtt.ErrMalformedTopic.Error(),
+		},
+		{
+			desc:    "publish with malformed subtopic",
+			client:  &sessionClient,
+			topic:   malformedSubtopics,
+			payload: payload,
+			logMsg:  mqtt.ErrMalformedSubtopic.Error(),
+		},
+		{
+			desc:    "publish with subtopic containing wrong character",
+			client:  &sessionClient,
+			topic:   wrongCharSubtopics,
+			payload: payload,
+			logMsg:  mqtt.ErrMalformedSubtopic.Error(),
+		},
+		{
+			desc:    "publish with subtopic",
+			client:  &sessionClient,
+			topic:   validSubtopic,
+			payload: payload,
+			logMsg:  subtopic,
+		},
+		{
+			desc:    "publish without subtopic",
+			client:  &sessionClient,
+			topic:   topic,
+			payload: payload,
+			logMsg:  "",
+		},
+	}
+
+	for _, tc := range cases {
+		handler.Publish(tc.client, &tc.topic, &tc.payload)
+		assert.Contains(t, logBuffer.String(), tc.logMsg)
+	}
+}
+
+func TestSubscribe(t *testing.T) {
+	handler := newHandler()
+	logBuffer.Reset()
+
+	cases := []struct {
+		desc   string
+		client *session.Client
+		topic  []string
+		logMsg string
+	}{
+		{
+			desc:   "subscribe without active session",
+			client: nil,
+			topic:  topics,
+			logMsg: mqtt.LogErrFailedSubscribe + mqtt.ErrClientNotInitialized.Error(),
+		},
+		{
+			desc:   "subscribe with valid session and topics",
+			client: &sessionClient,
+			topic:  topics,
+			logMsg: fmt.Sprintf(mqtt.LogInfoSubscribed, clientID, topics[0]),
+		},
+	}
+
+	for _, tc := range cases {
+		handler.Subscribe(tc.client, &tc.topic)
+		assert.Contains(t, logBuffer.String(), tc.logMsg)
+	}
+}
+
+func TestUnsubscribe(t *testing.T) {
+	handler := newHandler()
+	logBuffer.Reset()
+
+	cases := []struct {
+		desc   string
+		client *session.Client
+		topic  []string
+		logMsg string
+	}{
+		{
+			desc:   "unsubscribe without active session",
+			client: nil,
+			topic:  topics,
+			logMsg: mqtt.LogErrFailedUnsubscribe + mqtt.ErrClientNotInitialized.Error(),
+		},
+		{
+			desc:   "unsubscribe with valid session and topics",
+			client: &sessionClient,
+			topic:  topics,
+			logMsg: fmt.Sprintf(mqtt.LogInfoUnsubscribed, clientID, topics[0]),
+		},
+	}
+
+	for _, tc := range cases {
+		handler.Unsubscribe(tc.client, &tc.topic)
+		assert.Contains(t, logBuffer.String(), tc.logMsg)
+	}
+}
+
+func TestDisconnect(t *testing.T) {
+	handler := newHandler()
+	logBuffer.Reset()
+
+	cases := []struct {
+		desc   string
+		client *session.Client
+		topic  []string
+		logMsg string
+	}{
+		{
+			desc:   "disconnect without active session",
+			client: nil,
+			topic:  topics,
+			logMsg: mqtt.LogErrFailedDisconnect + mqtt.ErrClientNotInitialized.Error(),
+		},
+		{
+			desc:   "disconnect with valid session",
+			client: &sessionClient,
+			topic:  topics,
+			logMsg: fmt.Sprintf(mqtt.LogInfoDisconnected, clientID, thingID),
+		},
+	}
+
+	for _, tc := range cases {
+		handler.Disconnect(tc.client)
+		assert.Contains(t, logBuffer.String(), tc.logMsg)
+	}
+}
+
+func newHandler() session.Handler {
+	logger, err := logger.New(&logBuffer, "debug")
+	if err != nil {
+		log.Fatalf("failed to create logger: %s", err)
+	}
+
+	authClient := mocks.NewClient(map[string]string{password: thingID}, map[string]interface{}{chanID: thingID})
+	eventStore := mocks.NewEventStore()
+	return mqtt.NewHandler([]messaging.Publisher{mocks.NewPublisher()}, eventStore, logger, authClient)
+}
--- a/mqtt/mocks/auth.go
+++ b/mqtt/mocks/auth.go
@ -0,0 +1,32 @@
+package mocks
+
+import (
+	"context"
+	"github.com/mainflux/mainflux/pkg/auth"
+	"github.com/mainflux/mainflux/pkg/errors"
+)
+
+type MockClient struct {
+	key   map[string]string
+	conns map[string]interface{}
+}
+
+func NewClient(key map[string]string, conns map[string]interface{}) auth.Client {
+	return MockClient{key: key, conns: conns}
+}
+
+func (cli MockClient) Authorize(ctx context.Context, chanID, thingID string) error {
+	for k, v := range cli.conns {
+		if k == chanID && v == thingID {
+			return nil
+		}
+	}
+	return errors.ErrAuthentication
+}
+
+func (cli MockClient) Identify(ctx context.Context, thingKey string) (string, error) {
+	if id, ok := cli.key[thingKey]; ok {
+		return id, nil
+	}
+	return "", errors.ErrAuthentication
+}
--- a/mqtt/mocks/publisher.go
+++ b/mqtt/mocks/publisher.go
@ -0,0 +1,18 @@
+package mocks
+
+import "github.com/mainflux/mainflux/pkg/messaging"
+
+type MockPublisher struct{}
+
+// NewPublisher returns mock message publisher.
+func NewPublisher() messaging.Publisher {
+	return MockPublisher{}
+}
+
+func (pub MockPublisher) Publish(topic string, msg messaging.Message) error {
+	return nil
+}
+
+func (pub MockPublisher) Close() error {
+	return nil
+}
--- a/mqtt/mocks/redis.go
+++ b/mqtt/mocks/redis.go
@ -0,0 +1,19 @@
+package mocks
+
+import (
+	"github.com/mainflux/mainflux/mqtt/redis"
+)
+
+type MockEventStore struct{}
+
+func NewEventStore() redis.EventStore {
+	return MockEventStore{}
+}
+
+func (es MockEventStore) Connect(clientID string) error {
+	return nil
+}
+
+func (es MockEventStore) Disconnect(clientID string) error {
+	return nil
+}
--- a/mqtt/redis/streams.go
+++ b/mqtt/redis/streams.go
@ -16,8 +16,13 @@ const (
 	streamLen = 1000
 )

+type EventStore interface {
+	Connect(clientID string) error
+	Disconnect(clientID string) error
+}
+
 // EventStore is a struct used to store event streams in Redis
-type EventStore struct {
+type eventStore struct {
 	client   *redis.Client
 	instance string
 }
@ -25,13 +30,13 @@ type EventStore struct {
 // NewEventStore returns wrapper around mProxy service that sends
 // events to event store.
 func NewEventStore(client *redis.Client, instance string) EventStore {
-	return EventStore{
+	return eventStore{
 		client:   client,
 		instance: instance,
 	}
 }

-func (es EventStore) storeEvent(clientID, eventType string) error {
+func (es eventStore) storeEvent(clientID, eventType string) error {
 	timestamp := strconv.FormatInt(time.Now().Unix(), 10)

 	event := mqttEvent{
@ -55,11 +60,11 @@ func (es EventStore) storeEvent(clientID, eventType string) error {
 }

 // Connect issues event on MQTT CONNECT
-func (es EventStore) Connect(clientID string) error {
+func (es eventStore) Connect(clientID string) error {
 	return es.storeEvent(clientID, "connect")
 }

 // Disconnect issues event on MQTT CONNECT
-func (es EventStore) Disconnect(clientID string) error {
+func (es eventStore) Disconnect(clientID string) error {
 	return es.storeEvent(clientID, "disconnect")
 }