include custom errors

.travis.yml

@@ -18,6 +18,7 @@ script:
   - dep ensure
   - make lint
   - vendorcheck ./...
+  - make test
 
 after_success:
   - bash <(curl -s https://codecov.io/bash)

Makefile

@@ -17,4 +17,6 @@ lint:
 	gosimple ${PACKAGES} | awk '{print ""; print} END {if (NR > 0) {exit 1} else print "... ok"}' && \
 	echo -n ">> unused" && \
 	unused ${PACKAGES} | awk '{print ""; print} END {if (NR > 0) {exit 1} else print "... ok"}'
+test:
+	go test ${PACKAGES}
 

broker/amqp.go

@@ -5,6 +5,7 @@ import (
 	"time"
 
 	"github.com/golang/protobuf/proto"
+	"github.com/guilhermehubner/worker/errors"
 	"github.com/guilhermehubner/worker/log"
 	"github.com/jpillora/backoff"
 	"github.com/streadway/amqp"
@@ -58,7 +59,7 @@ func (b *AMQPBroker) GetJobStatus(jobName string) (Status, error) {
 func (b *AMQPBroker) GetMessage(jobName string) ([]byte, string) {
 	msg, ok, err := b.channel.Get(jobName, true)
 	if err != nil {
-		log.Get().Error(fmt.Sprintf("broker/amqp: fail to get message: %v", err))
+		log.Get().Error(errors.ErrChannelMessage.WithValue(err))
 		return nil, ""
 	}
 	if !ok {
@@ -78,14 +79,12 @@ func (b *AMQPBroker) Enqueue(jobName, messageID string, message proto.Message) e
 		nil,     // arguments
 	)
 	if err != nil {
-		// TODO
-		return err
+		return errors.ErrJobEnqueue.WithValue(err)
 	}
 
 	body, err := proto.Marshal(message)
 	if err != nil {
-		// TODO
-		return err
+		return errors.ErrMessageSerialize.WithValue(err)
 	}
 
 	err = b.channel.Publish(
@@ -102,7 +101,7 @@ func (b *AMQPBroker) Enqueue(jobName, messageID string, message proto.Message) e
 	)
 
 	if err != nil {
-		// TODO
+		return errors.ErrMessagePublishing.WithValue(err)
 	}
 
 	return err
@@ -119,8 +118,7 @@ func (b *AMQPBroker) EnqueueIn(jobName, messageID string, message proto.Message,
 		nil,     // arguments
 	)
 	if err != nil {
-		// TODO
-		return "", err
+		return "", errors.ErrJobEnqueue.WithValue(err)
 	}
 
 	queue, err := b.channel.QueueDeclare(
@@ -137,14 +135,12 @@ func (b *AMQPBroker) EnqueueIn(jobName, messageID string, message proto.Message,
 		},
 	)
 	if err != nil {
-		// TODO
-		return "", err
+		return "", errors.ErrJobEnqueue.WithValue(err)
 	}
 
 	body, err := proto.Marshal(message)
 	if err != nil {
-		// TODO
-		return "", err
+		return "", errors.ErrMessageSerialize.WithValue(err)
 	}
 
 	err = b.channel.Publish(
@@ -161,8 +157,7 @@ func (b *AMQPBroker) EnqueueIn(jobName, messageID string, message proto.Message,
 	)
 
 	if err != nil {
-		// TODO
-		return "", err
+		return "", errors.ErrMessagePublishing.WithValue(err)
 	}
 
 	return messageID, nil
@@ -172,21 +167,21 @@ func (b *AMQPBroker) connect() {
 	log.Get().Info("CONNECTING...")
 
 	for {
-		connection, err := amqp.Dial(b.url)
+		var err error
+		b.connection, err = amqp.Dial(b.url)
 		if err != nil {
-			log.Get().Error(fmt.Sprintf("broker/amqp: fail to connect: %v", err))
+			log.Get().Error(errors.ErrConnection.WithValue(err))
 			time.Sleep(b.backoff.Duration())
 			continue
 		}
 
-		channel, err := connection.Channel()
+		b.channel, err = b.connection.Channel()
 		if err != nil {
-			log.Get().Error(fmt.Sprintf("broker/amqp: fail to get connection channel: %v", err))
+			log.Get().Error(errors.ErrChannelUnavailable.WithValue(err))
+			time.Sleep(b.backoff.Duration())
 			continue
 		}
 
-		b.connection = connection
-		b.channel = channel
 		b.closed = b.connection.NotifyClose(make(chan *amqp.Error))
 		b.backoff.Reset()
 		b.connected = true

errors/error.go

@@ -0,0 +1,41 @@
+package errors
+
+import "fmt"
+
+type ErrorCode int
+
+const (
+	GeneralError ErrorCode = iota
+	FormatError
+	ParseError
+	ServiceError
+)
+
+var (
+	ErrChannelUnavailable = &Error{Code: ServiceError, Message: "channel unavailable"}
+	ErrChannelMessage     = &Error{Code: ServiceError, Message: "fail to get message"}
+	ErrConnection         = &Error{Code: ServiceError, Message: "fail to connect"}
+	ErrMessagePublishing  = &Error{Code: ServiceError, Message: "error on message publishing"}
+	ErrJobRegister        = &Error{Code: ServiceError, Message: "error on job register"}
+	ErrJobEnqueue         = &Error{Code: ServiceError, Message: "error on enqueue job"}
+	ErrEmptyURL           = &Error{Code: FormatError, Message: "needs a non-empty url"}
+	ErrMessageSerialize   = &Error{Code: ParseError, Message: "error on message serialize"}
+)
+
+type Error struct {
+	Code    ErrorCode
+	Message string
+	Err     error
+}
+
+func (e *Error) Error() string {
+	if e.Err != nil {
+		return fmt.Sprintf("[Error %d] %s: %s", e.Code, e.Message, e.Err)
+	}
+	return fmt.Sprintf("[Error %d] %s", e.Code, e.Message)
+}
+
+func (e *Error) WithValue(Err error) *Error {
+	e.Err = Err
+	return e
+}

errors/error_test.go

@@ -0,0 +1,40 @@
+package errors
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/pkg/errors"
+)
+
+func TestErrorMessage(t *testing.T) {
+	customError := errors.New("fail")
+
+	tt := []struct {
+		Err         *Error
+		Expectation string
+	}{
+		{
+			Err:         &Error{Code: FormatError, Message: "empty value"},
+			Expectation: fmt.Sprintf("[Error %d] empty value", FormatError),
+		},
+		{
+			Err:         &Error{Code: ServiceError, Message: "not found"},
+			Expectation: fmt.Sprintf("[Error %d] not found", ServiceError),
+		},
+		{
+			Err:         (&Error{Code: FormatError, Message: "nil pointer"}).WithValue(customError),
+			Expectation: fmt.Sprintf("[Error %d] nil pointer: fail", FormatError),
+		},
+		{
+			Err:         (&Error{Code: ServiceError, Message: "mysql error"}).WithValue(customError),
+			Expectation: fmt.Sprintf("[Error %d] mysql error: fail", ServiceError),
+		},
+	}
+
+	for _, tc := range tt {
+		if tc.Err.Error() != tc.Expectation {
+			t.Errorf("expect '%s', but got '%s'", tc.Expectation, tc.Err)
+		}
+	}
+}

examples/consumer/main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"log"
 
 	"golang.org/x/net/context"
 
@@ -10,7 +11,7 @@ import (
 )
 
 func main() {
-	wp := worker.NewWorkerPool("amqp://guest:guest@localhost:5672/", 5,
+	wp, err := worker.NewWorkerPool("amqp://guest:guest@localhost:5672/", 5,
 		func(ctx context.Context, next func(context.Context) error) error {
 			fmt.Print("Enter on Middleware 1 > ")
 			return next(ctx)
@@ -19,8 +20,11 @@ func main() {
 			fmt.Print("Enter on Middleware 2 > ")
 			return next(ctx)
 		})
+	if err != nil {
+		log.Fatal(err)
+	}
 
-	wp.RegisterJob(worker.JobType{
+	err = wp.RegisterJob(worker.JobType{
 		Name: "queue1",
 		Handle: func(ctx context.Context, gen worker.GenFunc) error {
 			msg := payload.Payload{}
@@ -36,8 +40,11 @@ func main() {
 		},
 		Priority: 10,
 	})
+	if err != nil {
+		log.Fatal(err)
+	}
 
-	wp.RegisterJob(worker.JobType{
+	err = wp.RegisterJob(worker.JobType{
 		Name: "queue2",
 		Handle: func(ctx context.Context, gen worker.GenFunc) error {
 			msg := payload.Payload{}
@@ -53,6 +60,9 @@ func main() {
 		},
 		Priority: 15,
 	})
+	if err != nil {
+		log.Fatal(err)
+	}
 
 	wp.Start()
 }

workerpool.go

@@ -9,6 +9,7 @@ import (
 	"syscall"
 
 	"github.com/guilhermehubner/worker/broker"
+	"github.com/guilhermehubner/worker/errors"
 	"github.com/guilhermehubner/worker/log"
 	"golang.org/x/net/context"
 )
@@ -89,13 +90,14 @@ func (wp *Pool) Start() {
 RegisterJob adds a job with handler for 'name' queue and allows you to specify options such as a
 job's priority and it's retry count.
 */
-func (wp *Pool) RegisterJob(job JobType) {
+func (wp *Pool) RegisterJob(job JobType) error {
 	err := wp.broker.RegisterJob(job.Name)
 	if err != nil {
-		// TODO
+		return errors.ErrJobRegister.WithValue(err)
 	}
 
 	wp.jobTypes = append(wp.jobTypes, job)
+	return nil
 }
 
 /*
@@ -105,9 +107,9 @@ URL is a string connection in the AMQP URI format.
 
 Concurrency specifies how many workers to spin up - each worker can process jobs concurrently.
 */
-func NewWorkerPool(url string, concurrency uint, middlewares ...Middleware) *Pool {
+func NewWorkerPool(url string, concurrency uint, middlewares ...Middleware) (*Pool, error) {
 	if strings.TrimSpace(url) == "" {
-		panic("worker workerpool: needs a non-empty url")
+		return nil, errors.ErrEmptyURL
 	}
 
 	wp := &Pool{
@@ -116,5 +118,5 @@ func NewWorkerPool(url string, concurrency uint, middlewares ...Middleware) *Poo
 		workers:     make([]*worker, concurrency),
 	}
 
-	return wp
+	return wp, nil
 }