Fix lint: goerr113 (#71)

* Add static errors

* Linter config

* Fix clean message

* Fix minor issues

.github/workflows/lint-go.yml

@@ -16,4 +16,4 @@ jobs:
     uses: kyma-project/eventing-tools/.github/workflows/lint-go-reusable.yml@main
     with:
         go-version: '1.21'
-        lint-config-uri: https://raw.githubusercontent.com/kyma-project/eventing-tools/4bc0e923b67ddb0a028171d8beebc3cb4a211d69/config/lint/.golangci.yaml
+        lint-config-uri: https://raw.githubusercontent.com/kyma-project/eventing-tools/cf7f3aebaad2d323730a9ab2a76f6cb78f459ee4/config/lint/.golangci.yaml

pkg/application/lister.go

@@ -18,6 +18,8 @@ import (
 	emlogger "github.com/kyma-project/eventing-manager/pkg/logger"
 )
 
+var ErrFailedToConvertObjectToUnstructured = errors.New("failed to convert runtime object to unstructured")
+
 type Lister struct {
 	lister cache.GenericLister
 }
@@ -41,7 +43,7 @@ func (l Lister) Get(name string) (*kymaappconnv1alpha1.Application, error) {
 
 	u, ok := object.(*unstructured.Unstructured)
 	if !ok {
-		return nil, errors.New("failed to convert runtime object to unstructured")
+		return nil, ErrFailedToConvertObjectToUnstructured
 	}
 
 	a := &kymaappconnv1alpha1.Application{}

pkg/cloudevents/builder/generic.go

@@ -12,6 +12,8 @@ import (
 	"github.com/kyma-project/eventing-manager/pkg/logger"
 )
 
+var ErrEventTypeCannotHaveEmptySegments = fmt.Errorf("event type cannot have empty segments after cleaning")
+
 // Perform a compile-time check.
 var _ CloudEventBuilder = &GenericBuilder{}
 
@@ -57,7 +59,7 @@ func (gb *GenericBuilder) Build(event ceevent.Event) (*ceevent.Event, error) {
 	// validate if the segments are not empty
 	segments := strings.Split(finalEventType, ".")
 	if DoesEmptySegmentsExist(segments) {
-		return nil, fmt.Errorf("event type cannot have empty segments after cleaning: %s", finalEventType)
+		return nil, fmt.Errorf("%w: %s", ErrEventTypeCannotHaveEmptySegments, finalEventType)
 	}
 	namedLogger.Debugf("using event type: %s", finalEventType)
 

pkg/cloudevents/eventtype/parse.go

@@ -8,14 +8,19 @@ import (
 	"github.com/kyma-project/eventing-publisher-proxy/pkg/cloudevents/builder"
 )
 
+var ( // Static errors.
+	ErrPrefixNotFound = errors.New("prefix not found")
+	ErrInvalidFormat  = errors.New("invalid format")
+)
+
 // parse splits the event-type using the given prefix and returns the application name, event and version
 // or an error if the event-type format is invalid.
 // A valid even-type format should be: prefix.application.event.version or application.event.version
 // where event should consist of at least two segments separated by "." (e.g. businessObject.operation).
 // Constraint: the application segment in the input event-type should not contain ".".
 func parse(eventType, prefix string) (string, string, string, error) {
 	if !strings.HasPrefix(eventType, prefix) {
-		return "", "", "", errors.New("prefix not found")
+		return "", "", "", ErrPrefixNotFound
 	}
 
 	// remove the prefix
@@ -26,7 +31,7 @@ func parse(eventType, prefix string) (string, string, string, error) {
 	// (e.g. application.businessObject.operation.version)
 	parts := strings.Split(eventType, ".")
 	if len(parts) < 4 || builder.DoesEmptySegmentsExist(parts) {
-		return "", "", "", errors.New("invalid format")
+		return "", "", "", ErrInvalidFormat
 	}
 
 	// parse the event-type segments

pkg/handler/handler_v1alpha1_test.go

@@ -34,6 +34,8 @@ import (
 	emlogger "github.com/kyma-project/eventing-manager/pkg/logger"
 )
 
+var ErrUnableToClean = fmt.Errorf("unable to clean")
+
 func Test_extractCloudEventFromRequest(t *testing.T) {
 	type args struct {
 		request *http.Request
@@ -253,14 +255,14 @@ func TestHandler_publishCloudEvents_v1alpha1(t *testing.T) {
 				collector: metrics.NewCollector(latency),
 				eventTypeCleaner: &eventtypetest.CleanerStub{
 					CleanType: "",
-					Error:     fmt.Errorf("I cannot clean"),
+					Error:     ErrUnableToClean,
 				},
 			},
 			args: args{
 				request: CreateValidBinaryRequestV1Alpha1(t),
 			},
 			wantStatus: 400,
-			wantBody:   []byte("I cannot clean"),
+			wantBody:   []byte("unable to clean"),
 			wantTEF:    "", // client error will not be recorded as EPP internal error. So no metric will be updated.
 		},
 		{

pkg/nats/connect.go

@@ -6,6 +6,8 @@ import (
 	"github.com/nats-io/nats.go"
 )
 
+var ErrNATSConnectionNotConnected = fmt.Errorf("NATS connection not connected")
+
 type Opt = nats.Option
 
 //nolint:gochecknoglobals // cloning functions as variables.
@@ -27,7 +29,7 @@ func Connect(url string, opts ...Opt) (*nats.Conn, error) {
 	}
 
 	if status := connection.Status(); status != nats.CONNECTED {
-		return nil, fmt.Errorf("NATS connection not connected with status:%v", status)
+		return nil, fmt.Errorf("%w with status:%v", ErrNATSConnectionNotConnected, status)
 	}
 
 	return connection, err

pkg/signals/signals.go

@@ -9,6 +9,8 @@ import (
 	"time"
 )
 
+var ErrReceivedTerminationSignal = errors.New("received a termination signal")
+
 //nolint:gochecknoglobals // defining channels
 var (
 	// onlyOneSignalHandler to make sure that only one signal handler is registered.
@@ -70,7 +72,7 @@ func (scc *signalContext) Err() error {
 	select {
 	case _, ok := <-scc.Done():
 		if !ok {
-			return errors.New("received a termination signal")
+			return ErrReceivedTerminationSignal
 		}
 	default:
 	}