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Event stream updates (#1981)

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- auto and manual acking
- retry limits
This commit is contained in:
Dominic Wong 2020-09-02 13:28:54 +01:00 committed by GitHub
parent 84f52fd7ac
commit 6bdf33c4ee
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GPG Key ID: 4AEE18F83AFDEB23
8 changed files with 383 additions and 299 deletions
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9
.github/workflows/tests.yml vendored
View File

@ -7,7 +7,6 @@ jobs:
name: Test repo
runs-on: ubuntu-latest
steps:
- name: Set up Go 1.13
uses: actions/setup-go@v1
with:
@ -34,9 +33,13 @@ jobs:
kubectl apply -f runtime/kubernetes/test/test.yaml
sudo mkdir -p /var/run/secrets/kubernetes.io/serviceaccount
sudo chmod 777 /var/run/secrets/kubernetes.io/serviceaccount
wget -qO- https://binaries.cockroachdb.com/cockroach-v20.1.4.linux-amd64.tgz | tar xvz
wget -qO- https://binaries.cockroachdb.com/cockroach-v20.1.4.linux-amd64.tgz | tar -xvz
cockroach-v20.1.4.linux-amd64/cockroach start-single-node --insecure &
go test -tags kubernetes -v ./...
wget -q https://github.com/nats-io/nats-streaming-server/releases/download/v0.18.0/nats-streaming-server-v0.18.0-linux-amd64.zip
unzip ./nats-streaming-server-v0.18.0-linux-amd64.zip
export PATH=$PATH:./nats-streaming-server-v0.18.0-linux-amd64
nats-streaming-server &
go test -tags kubernetes,nats -v ./...
- name: Notify of test failure
if: failure()

24
events/events.go
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@ -26,6 +26,9 @@ type Store interface {
Write(event *Event, opts ...WriteOption) error
}
type AckFunc func() error
type NackFunc func() error
// Event is the object returned by the broker when you subscribe to a topic
type Event struct {
// ID to uniquely identify the event
@ -38,9 +41,30 @@ type Event struct {
Metadata map[string]string
// Payload contains the encoded message
Payload []byte
ackFunc AckFunc
nackFunc NackFunc
}
// Unmarshal the events message into an object
func (e *Event) Unmarshal(v interface{}) error {
return json.Unmarshal(e.Payload, v)
}
// Ack acknowledges successful processing of the event in ManualAck mode
func (e *Event) Ack() error {
return e.ackFunc()
}
func (e *Event) SetAckFunc(f AckFunc) {
e.ackFunc = f
}
// Nack negatively acknowledges processing of the event (i.e. failure) in ManualAck mode
func (e *Event) Nack() error {
return e.nackFunc()
}
func (e *Event) SetNackFunc(f NackFunc) {
e.nackFunc = f
}

36
events/options.go
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@ -35,6 +35,17 @@ type SubscribeOptions struct {
// StartAtTime is the time from which the messages should be consumed from. If not provided then
// the messages will be consumed starting from the moment the Subscription starts.
StartAtTime time.Time
// AutoAck if true (default true), automatically acknowledges every message so it will not be redelivered.
// If false specifies that each message need ts to be manually acknowledged by the subscriber.
// If processing is successful the message should be ack'ed to remove the message from the stream.
// If processing is unsuccessful the message should be nack'ed (negative acknowledgement) which will mean it will
// remain on the stream to be processed again.
AutoAck bool
AckWait time.Duration
// RetryLimit indicates number of times a message is retried
RetryLimit int
// CustomRetries indicates whether to use RetryLimit
CustomRetries bool
}
// SubscribeOption sets attributes on SubscribeOptions
@ -54,6 +65,31 @@ func WithStartAtTime(t time.Time) SubscribeOption {
}
}
// WithAutoAck sets the AutoAck field on SubscribeOptions and an ackWait duration after which if no ack is received
// the message is requeued in case auto ack is turned off
func WithAutoAck(ack bool, ackWait time.Duration) SubscribeOption {
return func(o *SubscribeOptions) {
o.AutoAck = ack
o.AckWait = ackWait
}
}
// WithRetryLimit sets the RetryLimit field on SubscribeOptions.
// Set to -1 for infinite retries (default)
func WithRetryLimit(retries int) SubscribeOption {
return func(o *SubscribeOptions) {
o.RetryLimit = retries
o.CustomRetries = true
}
}
func (s SubscribeOptions) GetRetryLimit() int {
if !s.CustomRetries {
return -1
}
return s.RetryLimit
}
// WriteOptions contains all the options which can be provided when writing an event to a store
type WriteOptions struct {
// TTL is the duration the event should be recorded for, a zero value TTL indicates the event should

91
events/stream/memory/memory.go
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@ -32,6 +32,13 @@ type subscriber struct {
Queue string
Topic string
Channel chan events.Event
sync.RWMutex
retryMap map[string]int
retryLimit int
trackRetries bool
autoAck bool
ackWait time.Duration
}
type mem struct {
@ -102,17 +109,31 @@ func (m *mem) Subscribe(topic string, opts ...events.SubscribeOption) (<-chan ev
// parse the options
options := events.SubscribeOptions{
Queue: uuid.New().String(),
Queue: uuid.New().String(),
AutoAck: true,
}
for _, o := range opts {
o(&options)
}
// TODO RetryLimit
// setup the subscriber
sub := &subscriber{
Channel: make(chan events.Event),
Topic: topic,
Queue: options.Queue,
Channel: make(chan events.Event),
Topic: topic,
Queue: options.Queue,
retryMap: map[string]int{},
autoAck: true,
}
if options.CustomRetries {
sub.trackRetries = true
sub.retryLimit = options.GetRetryLimit()
}
if !options.AutoAck {
sub.autoAck = options.AutoAck
sub.ackWait = options.AckWait
}
// register the subscriber
@ -129,7 +150,7 @@ func (m *mem) Subscribe(topic string, opts ...events.SubscribeOption) (<-chan ev
return sub.Channel, nil
}
// lookupPreviousEvents finds events for a subscriber which occured before a given time and sends
// lookupPreviousEvents finds events for a subscriber which occurred before a given time and sends
// them into the subscribers channel
func (m *mem) lookupPreviousEvents(sub *subscriber, startTime time.Time) {
// lookup all events which match the topic (a blank topic will return all results)
@ -150,8 +171,7 @@ func (m *mem) lookupPreviousEvents(sub *subscriber, startTime time.Time) {
if ev.Timestamp.Unix() < startTime.Unix() {
continue
}
sub.Channel <- ev
sendEvent(&ev, sub)
}
}
@ -174,8 +194,59 @@ func (m *mem) handleEvent(ev *events.Event) {
// send the message to each channel async (since one channel might be blocked)
for _, sub := range subs {
go func(s *subscriber) {
s.Channel <- *ev
}(sub)
sendEvent(ev, sub)
}
}
func sendEvent(ev *events.Event, sub *subscriber) {
go func(s *subscriber) {
evCopy := *ev
if s.autoAck {
s.Channel <- evCopy
return
}
evCopy.SetAckFunc(ackFunc(s, evCopy))
evCopy.SetNackFunc(nackFunc(s, evCopy))
s.retryMap[evCopy.ID] = 0
tick := time.NewTicker(s.ackWait)
defer tick.Stop()
for range tick.C {
s.Lock()
count, ok := s.retryMap[evCopy.ID]
s.Unlock()
if !ok {
// success
break
}
if s.trackRetries && count > s.retryLimit {
if logger.V(logger.ErrorLevel, logger.DefaultLogger) {
logger.Errorf("Message retry limit reached, discarding: %v %d %d", evCopy.ID, count, s.retryLimit)
}
s.Lock()
delete(s.retryMap, evCopy.ID)
s.Unlock()
return
}
s.Channel <- evCopy
s.Lock()
s.retryMap[evCopy.ID] = count + 1
s.Unlock()
}
}(sub)
}
func ackFunc(s *subscriber, evCopy events.Event) func() error {
return func() error {
s.Lock()
delete(s.retryMap, evCopy.ID)
s.Unlock()
return nil
}
}
func nackFunc(s *subscriber, evCopy events.Event) func() error {
return func() error {
return nil
}
}

134
events/stream/memory/memory_test.go
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@ -1,135 +1 @@
package memory
import (
"sync"
"testing"
"time"
"github.com/google/uuid"
"github.com/micro/go-micro/v3/events"
"github.com/stretchr/testify/assert"
)
type testPayload struct {
Message string
}
func TestStream(t *testing.T) {
stream, err := NewStream()
assert.Nilf(t, err, "NewStream should not return an error")
assert.NotNilf(t, stream, "NewStream should return a stream object")
// TestMissingTopic will test the topic validation on publish
t.Run("TestMissingTopic", func(t *testing.T) {
err := stream.Publish("", nil)
assert.Equalf(t, err, events.ErrMissingTopic, "Publishing to a blank topic should return an error")
})
// TestSubscribeTopic will publish a message to the test topic. The subscriber will subscribe to the
// same test topic.
t.Run("TestSubscribeTopic", func(t *testing.T) {
payload := &testPayload{Message: "HelloWorld"}
metadata := map[string]string{"foo": "bar"}
// create the subscriber
evChan, err := stream.Subscribe("test")
assert.Nilf(t, err, "Subscribe should not return an error")
// setup the subscriber async
var wg sync.WaitGroup
go func() {
timeout := time.NewTimer(time.Millisecond * 250)
select {
case event, _ := <-evChan:
assert.NotNilf(t, event, "The message was nil")
assert.Equal(t, event.Metadata, metadata, "Metadata didn't match")
var result testPayload
err = event.Unmarshal(&result)
assert.Nil(t, err, "Error decoding result")
assert.Equal(t, result, *payload, "Payload didn't match")
wg.Done()
case <-timeout.C:
t.Fatalf("Event was not recieved")
}
}()
err = stream.Publish("test", payload, events.WithMetadata(metadata))
assert.Nil(t, err, "Publishing a valid message should not return an error")
wg.Add(1)
// wait for the subscriber to recieve the message or timeout
wg.Wait()
})
// TestSubscribeQueue will publish a message to a random topic. Two subscribers will then consume
// the message from the firehose topic with different queues. The second subscriber will be registered
// after the message is published to test durability.
t.Run("TestSubscribeQueue", func(t *testing.T) {
topic := uuid.New().String()
payload := &testPayload{Message: "HelloWorld"}
metadata := map[string]string{"foo": "bar"}
// create the first subscriber
evChan1, err := stream.Subscribe(topic)
assert.Nilf(t, err, "Subscribe should not return an error")
// setup the subscriber async
var wg sync.WaitGroup
go func() {
timeout := time.NewTimer(time.Millisecond * 250)
select {
case event, _ := <-evChan1:
assert.NotNilf(t, event, "The message was nil")
assert.Equal(t, event.Metadata, metadata, "Metadata didn't match")
var result testPayload
err = event.Unmarshal(&result)
assert.Nil(t, err, "Error decoding result")
assert.Equal(t, result, *payload, "Payload didn't match")
wg.Done()
case <-timeout.C:
t.Fatalf("Event was not recieved")
}
}()
err = stream.Publish(topic, payload, events.WithMetadata(metadata))
assert.Nil(t, err, "Publishing a valid message should not return an error")
wg.Add(2)
// create the second subscriber
evChan2, err := stream.Subscribe(topic,
events.WithQueue("second_queue"),
events.WithStartAtTime(time.Now().Add(time.Minute*-1)),
)
assert.Nilf(t, err, "Subscribe should not return an error")
go func() {
timeout := time.NewTimer(time.Millisecond * 250)
select {
case event, _ := <-evChan2:
assert.NotNilf(t, event, "The message was nil")
assert.Equal(t, event.Metadata, metadata, "Metadata didn't match")
var result testPayload
err = event.Unmarshal(&result)
assert.Nil(t, err, "Error decoding result")
assert.Equal(t, result, *payload, "Payload didn't match")
wg.Done()
case <-timeout.C:
t.Fatalf("Event was not recieved")
}
}()
// wait for the subscriber to recieve the message or timeout
wg.Wait()
})
}

34
events/stream/nats/nats.go
View File

@ -116,7 +116,8 @@ func (s *stream) Subscribe(topic string, opts ...events.SubscribeOption) (<-chan
// parse the options
options := events.SubscribeOptions{
Queue: uuid.New().String(),
Queue: uuid.New().String(),
AutoAck: true,
}
for _, o := range opts {
o(&options)
@ -125,19 +126,43 @@ func (s *stream) Subscribe(topic string, opts ...events.SubscribeOption) (<-chan
// setup the subscriber
c := make(chan events.Event)
handleMsg := func(m *stan.Msg) {
// poison message handling
if options.GetRetryLimit() > -1 && m.Redelivered && int(m.RedeliveryCount) > options.GetRetryLimit() {
if logger.V(logger.ErrorLevel, logger.DefaultLogger) {
logger.Errorf("Message retry limit reached, discarding: %v", m.Sequence)
}
m.Ack() // ignoring error
return
}
// decode the message
var evt events.Event
if err := json.Unmarshal(m.Data, &evt); err != nil {
if logger.V(logger.ErrorLevel, logger.DefaultLogger) {
logger.Errorf("Error decoding message: %v", err)
}
// not ackknowledging the message is the way to indicate an error occured
// not acknowledging the message is the way to indicate an error occurred
return
}
if !options.AutoAck {
// set up the ack funcs
evt.SetAckFunc(func() error {
return m.Ack()
})
evt.SetNackFunc(func() error {
// noop. not acknowledging the message is the way to indicate an error occurred
// we have to wait for the ack wait to kick in before the message is resent
return nil
})
}
// push onto the channel and wait for the consumer to take the event off before we acknowledge it.
c <- evt
if !options.AutoAck {
return
}
if err := m.Ack(); err != nil && logger.V(logger.ErrorLevel, logger.DefaultLogger) {
logger.Errorf("Error acknowledging message: %v", err)
}
@ -149,7 +174,10 @@ func (s *stream) Subscribe(topic string, opts ...events.SubscribeOption) (<-chan
stan.SetManualAckMode(),
}
if options.StartAtTime.Unix() > 0 {
stan.StartAtTime(options.StartAtTime)
subOpts = append(subOpts, stan.StartAtTime(options.StartAtTime))
}
if options.AckWait > 0 {
subOpts = append(subOpts, stan.AckWait(options.AckWait))
}
// connect the subscriber

151
events/stream/nats/nats_test.go
View File

@ -1,150 +1,3 @@
// +build nats
package nats
import (
"net"
"os/exec"
"sync"
"testing"
"time"
"github.com/google/uuid"
"github.com/micro/go-micro/v3/events"
"github.com/stretchr/testify/assert"
)
type testPayload struct {
Message string
}
func TestStream(t *testing.T) {
_, err := exec.LookPath("nats-streaming-server")
if err != nil {
t.Skipf("Skipping nats test, nats-streaming-server binary is not detected")
}
conn, err := net.DialTimeout("tcp", ":4222", time.Millisecond*100)
if err != nil {
t.Skipf("Skipping nats test, could not connect to cluster on port 4222: %v", err)
}
if err := conn.Close(); err != nil {
t.Fatalf("Error closing test tcp connection to nats cluster")
}
stream, err := NewStream(ClusterID("test-cluster"))
assert.Nilf(t, err, "NewStream should not return an error")
assert.NotNilf(t, stream, "NewStream should return a stream object")
// TestMissingTopic will test the topic validation on publish
t.Run("TestMissingTopic", func(t *testing.T) {
err := stream.Publish("", nil)
assert.Equalf(t, err, events.ErrMissingTopic, "Publishing to a blank topic should return an error")
})
// TestSubscribeTopic will publish a message to the test topic. The subscriber will subscribe to the
// same test topic.
t.Run("TestSubscribeTopic", func(t *testing.T) {
payload := &testPayload{Message: "HelloWorld"}
metadata := map[string]string{"foo": "bar"}
// create the subscriber
evChan, err := stream.Subscribe("test")
assert.Nilf(t, err, "Subscribe should not return an error")
// setup the subscriber async
var wg sync.WaitGroup
go func() {
timeout := time.NewTimer(time.Millisecond * 250)
select {
case event, _ := <-evChan:
assert.NotNilf(t, event, "The message was nil")
assert.Equal(t, event.Metadata, metadata, "Metadata didn't match")
var result testPayload
err = event.Unmarshal(&result)
assert.Nil(t, err, "Error decoding result")
assert.Equal(t, result, *payload, "Payload didn't match")
wg.Done()
case <-timeout.C:
t.Fatalf("Event was not recieved")
}
}()
err = stream.Publish("test", payload, events.WithMetadata(metadata))
assert.Nil(t, err, "Publishing a valid message should not return an error")
wg.Add(1)
// wait for the subscriber to recieve the message or timeout
wg.Wait()
})
// TestSubscribeQueue will publish a message to a random topic. Two subscribers will then consume
// the message from the firehose topic with different queues. The second subscriber will be registered
// after the message is published to test durability.
t.Run("TestSubscribeQueue", func(t *testing.T) {
topic := uuid.New().String()
payload := &testPayload{Message: "HelloWorld"}
metadata := map[string]string{"foo": "bar"}
// create the first subscriber
evChan1, err := stream.Subscribe(topic)
assert.Nilf(t, err, "Subscribe should not return an error")
// setup the subscriber async
var wg sync.WaitGroup
go func() {
timeout := time.NewTimer(time.Millisecond * 250)
select {
case event, _ := <-evChan1:
assert.NotNilf(t, event, "The message was nil")
assert.Equal(t, event.Metadata, metadata, "Metadata didn't match")
var result testPayload
err = event.Unmarshal(&result)
assert.Nil(t, err, "Error decoding result")
assert.Equal(t, result, *payload, "Payload didn't match")
wg.Done()
case <-timeout.C:
t.Fatalf("Event was not recieved")
}
}()
err = stream.Publish(topic, payload, events.WithMetadata(metadata))
assert.Nil(t, err, "Publishing a valid message should not return an error")
wg.Add(2)
// create the second subscriber
evChan2, err := stream.Subscribe(topic,
events.WithQueue("second_queue"),
events.WithStartAtTime(time.Now().Add(time.Minute*-1)),
)
assert.Nilf(t, err, "Subscribe should not return an error")
go func() {
timeout := time.NewTimer(time.Millisecond * 250)
select {
case event, _ := <-evChan2:
assert.NotNilf(t, event, "The message was nil")
assert.Equal(t, event.Metadata, metadata, "Metadata didn't match")
var result testPayload
err = event.Unmarshal(&result)
assert.Nil(t, err, "Error decoding result")
assert.Equal(t, result, *payload, "Payload didn't match")
wg.Done()
case <-timeout.C:
t.Fatalf("Event was not recieved")
}
}()
// wait for the subscriber to recieve the message or timeout
wg.Wait()
})
}

203
events/stream/test/stream_test.go Normal file
View File

@ -0,0 +1,203 @@
// +build nats
package test
import (
"sync"
"testing"
"time"
"github.com/micro/go-micro/v3/events"
"github.com/micro/go-micro/v3/events/stream/memory"
"github.com/micro/go-micro/v3/events/stream/nats"
"github.com/google/uuid"
"github.com/stretchr/testify/assert"
)
type testPayload struct {
Message string
}
type testCase struct {
str events.Stream
name string
}
func TestStream(t *testing.T) {
tcs := []testCase{}
// NATS specific setup
stream, err := nats.NewStream(nats.ClusterID("test-cluster"))
assert.Nilf(t, err, "NewStream should not return an error")
assert.NotNilf(t, stream, "NewStream should return a stream object")
tcs = append(tcs, testCase{str: stream, name: "nats"})
stream, err = memory.NewStream()
assert.Nilf(t, err, "NewStream should not return an error")
assert.NotNilf(t, stream, "NewStream should return a stream object")
tcs = append(tcs, testCase{str: stream, name: "memory"})
for _, tc := range tcs {
t.Run(tc.name, func(t *testing.T) {
runTestStream(t, tc.str)
})
}
}
func runTestStream(t *testing.T, stream events.Stream) {
// TestMissingTopic will test the topic validation on publish
t.Run("TestMissingTopic", func(t *testing.T) {
err := stream.Publish("", nil)
assert.Equalf(t, err, events.ErrMissingTopic, "Publishing to a blank topic should return an error")
})
// TestSubscribeTopic will publish a message to the test topic. The subscriber will subscribe to the
// same test topic.
t.Run("TestSubscribeTopic", func(t *testing.T) {
payload := &testPayload{Message: "HelloWorld"}
metadata := map[string]string{"foo": "bar"}
// create the subscriber
evChan, err := stream.Subscribe("test")
assert.Nilf(t, err, "Subscribe should not return an error")
// setup the subscriber async
var wg sync.WaitGroup
go func() {
timeout := time.NewTimer(time.Millisecond * 250)
select {
case event, _ := <-evChan:
assert.NotNilf(t, event, "The message was nil")
assert.Equal(t, event.Metadata, metadata, "Metadata didn't match")
var result testPayload
err = event.Unmarshal(&result)
assert.Nil(t, err, "Error decoding result")
assert.Equal(t, result, *payload, "Payload didn't match")
wg.Done()
case <-timeout.C:
t.Fatalf("Event was not recieved")
}
}()
err = stream.Publish("test", payload, events.WithMetadata(metadata))
assert.Nil(t, err, "Publishing a valid message should not return an error")
wg.Add(1)
// wait for the subscriber to recieve the message or timeout
wg.Wait()
})
// TestSubscribeQueue will publish a message to a random topic. Two subscribers will then consume
// the message from the firehose topic with different queues. The second subscriber will be registered
// after the message is published to test durability.
t.Run("TestSubscribeQueue", func(t *testing.T) {
topic := uuid.New().String()
payload := &testPayload{Message: "HelloWorld"}
metadata := map[string]string{"foo": "bar"}
// create the first subscriber
evChan1, err := stream.Subscribe(topic)
assert.Nilf(t, err, "Subscribe should not return an error")
// setup the subscriber async
var wg sync.WaitGroup
go func() {
timeout := time.NewTimer(time.Millisecond * 250)
select {
case event, _ := <-evChan1:
assert.NotNilf(t, event, "The message was nil")
assert.Equal(t, event.Metadata, metadata, "Metadata didn't match")
var result testPayload
err = event.Unmarshal(&result)
assert.Nil(t, err, "Error decoding result")
assert.Equal(t, result, *payload, "Payload didn't match")
wg.Done()
case <-timeout.C:
t.Fatalf("Event was not recieved")
}
}()
err = stream.Publish(topic, payload, events.WithMetadata(metadata))
assert.Nil(t, err, "Publishing a valid message should not return an error")
wg.Add(2)
// create the second subscriber
evChan2, err := stream.Subscribe(topic,
events.WithQueue("second_queue"),
events.WithStartAtTime(time.Now().Add(time.Minute*-1)),
)
assert.Nilf(t, err, "Subscribe should not return an error")
go func() {
timeout := time.NewTimer(time.Second * 1)
select {
case event, _ := <-evChan2:
assert.NotNilf(t, event, "The message was nil")
assert.Equal(t, event.Metadata, metadata, "Metadata didn't match")
var result testPayload
err = event.Unmarshal(&result)
assert.Nil(t, err, "Error decoding result")
assert.Equal(t, result, *payload, "Payload didn't match")
wg.Done()
case <-timeout.C:
t.Fatalf("Event was not recieved")
}
}()
// wait for the subscriber to recieve the message or timeout
wg.Wait()
})
t.Run("AckingNacking", func(t *testing.T) {
ch, err := stream.Subscribe("foobarAck", events.WithAutoAck(false, 5*time.Second))
assert.NoError(t, err, "Unexpected error subscribing")
assert.NoError(t, stream.Publish("foobarAck", map[string]string{"foo": "message 1"}))
assert.NoError(t, stream.Publish("foobarAck", map[string]string{"foo": "message 2"}))
ev := <-ch
ev.Ack()
ev = <-ch
nacked := ev.ID
ev.Nack()
select {
case ev = <-ch:
assert.Equal(t, ev.ID, nacked, "Nacked message should have been received again")
assert.NoError(t, ev.Ack())
case <-time.After(7 * time.Second):
t.Fatalf("Timed out waiting for message to be put back on queue")
}
})
t.Run("Retries", func(t *testing.T) {
ch, err := stream.Subscribe("foobarRetries", events.WithAutoAck(false, 5*time.Second), events.WithRetryLimit(1))
assert.NoError(t, err, "Unexpected error subscribing")
assert.NoError(t, stream.Publish("foobarRetries", map[string]string{"foo": "message 1"}))
ev := <-ch
id := ev.ID
ev.Nack()
ev = <-ch
assert.Equal(t, id, ev.ID, "Nacked message should have been received again")
ev.Nack()
select {
case ev = <-ch:
t.Fatalf("Unexpected event received")
case <-time.After(7 * time.Second):
}
})
}