Use joined errors

Go 1.20 added support for joined errors; using those instead of error
slices allows typical nil/non-nil semantics to be used, and allows all
error messages to be shown simultaneously when asserting.

This gets rid of HandleErrorList, and with it the implied
generic/validation error distinction. To handle that, HandleError
takes an additional error type parameter, making the distinction
explicit.

Signed-off-by: Stephen Kitt <skitt@redhat.com>

cmd/skupper/main.go

@@ -13,5 +13,5 @@ func main() {
 	rootCmd := root.NewSkupperRootCommand()
 
 	err := rootCmd.Execute()
-	utils.HandleError(err)
+	utils.HandleError(utils.GenericError, err)
 }

internal/cmd/generate-doc/main.go

@@ -2,9 +2,10 @@ package main
 
 import (
 	"fmt"
-	"github.com/skupperproject/skupper/internal/cmd/skupper/common/utils"
 	"os"
 
+	"github.com/skupperproject/skupper/internal/cmd/skupper/common/utils"
+
 	"github.com/skupperproject/skupper/internal/cmd/skupper/root"
 	"github.com/spf13/cobra/doc"
 )
@@ -15,7 +16,7 @@ func main() {
 		fmt.Printf("%s\n\nUsage: generate-doc ./docsoutput\n", err)
 		os.Exit(1)
 	}
-	utils.HandleError(doc.GenMarkdownTree(root.NewSkupperRootCommand(), path))
+	utils.HandleError(utils.GenericError, doc.GenMarkdownTree(root.NewSkupperRootCommand(), path))
 
 }
 

internal/cmd/skupper/common/command.go

@@ -2,14 +2,15 @@ package common
 
 import (
 	"fmt"
+
 	"github.com/skupperproject/skupper/api/types"
 	"github.com/skupperproject/skupper/internal/cmd/skupper/common/utils"
 	"github.com/spf13/cobra"
 )
 
 type SkupperCommand interface {
 	NewClient(cobraCommand *cobra.Command, args []string)
-	ValidateInput(args []string) []error
+	ValidateInput(args []string) error
 	InputToOptions()
 	Run() error
 	WaitUntil() error
@@ -51,12 +52,12 @@ func ConfigureCobraCommand(configuredPlatform types.Platform, description Skuppe
 			return nil
 		},
 		Run: func(cmd *cobra.Command, args []string) {
-			utils.HandleErrorList(skupperCommand.ValidateInput(args))
+			utils.HandleError(utils.ValidationError, skupperCommand.ValidateInput(args))
 			skupperCommand.InputToOptions()
-			utils.HandleError(skupperCommand.Run())
+			utils.HandleError(utils.GenericError, skupperCommand.Run())
 		},
 		PostRun: func(cmd *cobra.Command, args []string) {
-			utils.HandleError(skupperCommand.WaitUntil())
+			utils.HandleError(utils.GenericError, skupperCommand.WaitUntil())
 		},
 	}
 

internal/cmd/skupper/common/command_test.go

@@ -1,10 +1,11 @@
 package common
 
 import (
+	"testing"
+
 	"github.com/skupperproject/skupper/api/types"
 	"github.com/spf13/cobra"
 	"gotest.tools/assert"
-	"testing"
 )
 
 type MockSkupperCommand struct {
@@ -19,7 +20,7 @@ func (m *MockSkupperCommand) NewClient(cmd *cobra.Command, args []string) {
 	m.CalledNewClient = true
 }
 
-func (m *MockSkupperCommand) ValidateInput(args []string) []error {
+func (m *MockSkupperCommand) ValidateInput(args []string) error {
 	m.CalledValidateInput = true
 	return nil
 }

internal/cmd/skupper/common/utils/handle_error.go

@@ -5,32 +5,16 @@ import (
 	"syscall"
 )
 
+type ErrorType int
+
 const (
-	GenericError    = 1
-	ValidationError = 2
+	GenericError    ErrorType = 1
+	ValidationError ErrorType = 2
 )
 
-func HandleError(err error) {
+func HandleError(errType ErrorType, err error) {
 	if err != nil {
 		fmt.Println(err)
-		syscall.Exit(GenericError)
-	}
-}
-
-func HandleErrorList(errList []error) {
-	if errList != nil && len(errList) > 0 {
-		for _, err := range errList {
-			fmt.Println(err)
-		}
-
-		syscall.Exit(ValidationError)
-	}
-}
-
-func ErrorsToMessages(errs []error) []string {
-	messages := make([]string, len(errs))
-	for i, err := range errs {
-		messages[i] = err.Error()
+		syscall.Exit(int(errType))
 	}
-	return messages
 }

internal/cmd/skupper/connector/kube/connector_create.go

@@ -2,6 +2,7 @@ package kube
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"strconv"
 	"time"
@@ -15,7 +16,7 @@ import (
 	pkgUtils "github.com/skupperproject/skupper/pkg/utils"
 	"github.com/skupperproject/skupper/pkg/utils/validator"
 	"github.com/spf13/cobra"
-	"k8s.io/apimachinery/pkg/api/errors"
+	k8serrs "k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/client-go/kubernetes"
 )
@@ -45,14 +46,14 @@ func NewCmdConnectorCreate() *CmdConnectorCreate {
 
 func (cmd *CmdConnectorCreate) NewClient(cobraCommand *cobra.Command, args []string) {
 	cli, err := client.NewClient(cobraCommand.Flag("namespace").Value.String(), cobraCommand.Flag("context").Value.String(), cobraCommand.Flag("kubeconfig").Value.String())
-	utils.HandleError(err)
+	utils.HandleError(utils.GenericError, err)
 
 	cmd.client = cli.GetSkupperClient().SkupperV2alpha1()
 	cmd.namespace = cli.Namespace
 	cmd.KubeClient = cli.Kube
 }
 
-func (cmd *CmdConnectorCreate) ValidateInput(args []string) []error {
+func (cmd *CmdConnectorCreate) ValidateInput(args []string) error {
 	var validationErrors []error
 	resourceStringValidator := validator.NewResourceStringValidator()
 	numberValidator := validator.NewNumberValidator()
@@ -92,7 +93,7 @@ func (cmd *CmdConnectorCreate) ValidateInput(args []string) []error {
 	// Validate if there is already a Connector with this name in the namespace
 	if cmd.name != "" {
 		connector, err := cmd.client.Connectors(cmd.namespace).Get(context.TODO(), cmd.name, metav1.GetOptions{})
-		if connector != nil && !errors.IsNotFound(err) {
+		if connector != nil && !k8serrs.IsNotFound(err) {
 			validationErrors = append(validationErrors, fmt.Errorf("there is already a connector %s created for namespace %s", cmd.name, cmd.namespace))
 		}
 	}
@@ -203,7 +204,7 @@ func (cmd *CmdConnectorCreate) ValidateInput(args []string) []error {
 			validationErrors = append(validationErrors, fmt.Errorf("output type is not valid: %s", err))
 		}
 	}
-	return validationErrors
+	return errors.Join(validationErrors...)
 }
 
 func (cmd *CmdConnectorCreate) InputToOptions() {