Move Acknowledger to its own package (#26)

.codeclimate.yml

@@ -4,6 +4,9 @@ checks:
   method-complexity:
     config:
       threshold: 10
+  method-length:
+    config:
+      threshold: 32
 
 plugins:
   gofmt:

acknowledger/acknowledger.go

@@ -0,0 +1,40 @@
+package acknowledger
+
+import (
+	"github.com/corvus-ch/rabbitmq-cli-consumer/config"
+	"github.com/corvus-ch/rabbitmq-cli-consumer/delivery"
+)
+
+// Mapping of script exit codes and message acknowledgment.
+const (
+	exitAck           = 0
+	exitReject        = 3
+	exitRejectRequeue = 4
+	exitNack          = 5
+	exitNackRequeue   = 6
+)
+
+// Acknowledger does message acknowledgment depending on the scripts exit code.
+type Acknowledger interface {
+	Ack(d delivery.Delivery, code int) error
+}
+
+// New creates new Acknowledger using strict or default behaviour.
+func New(strict bool, onFailure int) Acknowledger {
+	if strict {
+		return &Strict{}
+	}
+
+	return &Default{
+		OnFailure: onFailure,
+	}
+}
+
+// NewFromConfig creates a new Acknowledger from the given configuration.
+func NewFromConfig(cfg *config.Config) Acknowledger {
+	if cfg.RabbitMq.Stricfailure {
+		return &Strict{}
+	}
+
+	return &Default{cfg.RabbitMq.Onfailure}
+}

acknowledger/default.go

@@ -0,0 +1,30 @@
+package acknowledger
+
+import "github.com/corvus-ch/rabbitmq-cli-consumer/delivery"
+
+// Default is an Acknowledger implementation using a configurable default behaviour for script errors.
+type Default struct {
+	OnFailure int
+}
+
+// Ack acknowledges the message on success or negatively acknowledges or rejects the message according to the configured
+// on error behaviour.
+func (a Default) Ack(d delivery.Delivery, code int) error {
+	if code == exitAck {
+		d.Ack()
+		return nil
+	}
+	switch a.OnFailure {
+	case exitReject:
+		d.Reject(false)
+	case exitRejectRequeue:
+		d.Reject(true)
+	case exitNack:
+		d.Nack(false)
+	case exitNackRequeue:
+		d.Nack(true)
+	default:
+		d.Nack(true)
+	}
+	return nil
+}

acknowledger/strict.go

@@ -0,0 +1,32 @@
+package acknowledger
+
+import (
+	"fmt"
+
+	"github.com/corvus-ch/rabbitmq-cli-consumer/delivery"
+)
+
+// Strict is an Acknowledger implementation strictly using the scripts exit code.
+type Strict struct{}
+
+// Ack acknowledges the message on success or negatively acknowledges or rejects the message according to the scripts
+// exit code. It is an error if the script does not exit with one of the predefined exit codes.
+func (a Strict) Ack(d delivery.Delivery, code int) error {
+	switch code {
+	case exitAck:
+		d.Ack()
+	case exitReject:
+		d.Reject(false)
+	case exitRejectRequeue:
+		d.Reject(true)
+	case exitNack:
+		d.Nack(false)
+	case exitNackRequeue:
+		d.Nack(true)
+	default:
+		d.Nack(true)
+		return fmt.Errorf("unexpected exit code %v", code)
+	}
+
+	return nil
+}

config/config.go

@@ -10,15 +10,16 @@ import (
 
 type Config struct {
 	RabbitMq struct {
-		AmqpUrl     string
-		Host        string
-		Username    string
-		Password    string
-		Port        string
-		Vhost       string
-		Queue       string
-		Compression bool
-		Onfailure   int
+		AmqpUrl      string
+		Host         string
+		Username     string
+		Password     string
+		Port         string
+		Vhost        string
+		Queue        string
+		Compression  bool
+		Onfailure    int
+		Stricfailure bool
 	}
 	Prefetch struct {
 		Count  int

consumer/consume_test.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/bouk/monkey"
 	log "github.com/corvus-ch/logr/buffered"
+	"github.com/corvus-ch/rabbitmq-cli-consumer/acknowledger"
 	"github.com/corvus-ch/rabbitmq-cli-consumer/command"
 	"github.com/corvus-ch/rabbitmq-cli-consumer/consumer"
 	"github.com/corvus-ch/rabbitmq-cli-consumer/delivery"
@@ -49,7 +50,7 @@ func TestProcessing(t *testing.T) {
 			body := []byte(test.name)
 			c := consumer.Consumer{
 				Builder:      b,
-				Acknowledger: consumer.NewAcknowledger(test.strict, test.onFailure),
+				Acknowledger: acknowledger.New(test.strict, test.onFailure),
 			}
 
 			b.On("GetCommand", p, di, body).Return(cmd, nil)
@@ -108,7 +109,7 @@ func TestStrictDefault(t *testing.T) {
 	body := []byte("strictDefault")
 	c := consumer.Consumer{
 		Builder:      b,
-		Acknowledger: &consumer.StrictAcknowledger{},
+		Acknowledger: &acknowledger.Strict{},
 		Log:          log.New(0),
 	}
 

consumer/consumer.go

@@ -5,6 +5,7 @@ import (
 	"io"
 	"os"
 
+	"github.com/corvus-ch/rabbitmq-cli-consumer/acknowledger"
 	"github.com/corvus-ch/rabbitmq-cli-consumer/command"
 	"github.com/corvus-ch/rabbitmq-cli-consumer/config"
 	"github.com/corvus-ch/rabbitmq-cli-consumer/delivery"
@@ -15,7 +16,7 @@ import (
 type Consumer struct {
 	Connection   Connection
 	Builder      command.Builder
-	Acknowledger Acknowledger
+	Acknowledger acknowledger.Acknowledger
 	Log          logr.Logger
 }
 
@@ -75,7 +76,7 @@ func (c *Consumer) ProcessMessage(d delivery.Delivery) {
 }
 
 // New returns a initialized consumer based on config
-func New(cfg *config.Config, builder command.Builder, ack Acknowledger, l logr.Logger) (*Consumer, error) {
+func New(cfg *config.Config, builder command.Builder, ack acknowledger.Acknowledger, l logr.Logger) (*Consumer, error) {
 	conn, err := NewConnection(cfg, l)
 	if err != nil {
 		return nil, err

main.go

@@ -6,6 +6,7 @@ import (
 	"os"
 
 	"github.com/codegangsta/cli"
+	"github.com/corvus-ch/rabbitmq-cli-consumer/acknowledger"
 	"github.com/corvus-ch/rabbitmq-cli-consumer/command"
 	"github.com/corvus-ch/rabbitmq-cli-consumer/config"
 	"github.com/corvus-ch/rabbitmq-cli-consumer/consumer"
@@ -102,7 +103,7 @@ func Action(c *cli.Context) error {
 		return fmt.Errorf("failed to create command builder: %v", err)
 	}
 
-	ack := consumer.NewAcknowledger(c.Bool("strict-exit-code"), cfg.RabbitMq.Onfailure)
+	ack := acknowledger.NewFromConfig(cfg)
 
 	client, err := consumer.New(cfg, builder, ack, l)
 	if err != nil {
@@ -179,6 +180,10 @@ func LoadConfiguration(c *cli.Context) (*config.Config, error) {
 		cfg.Logs.Verbose = c.Bool("verbose")
 	}
 
+	if c.IsSet("strict-exit-code") {
+		cfg.RabbitMq.Stricfailure = c.Bool("strict-exit-code")
+	}
+
 	return cfg, nil
 }