Implement better error handling (kyma-project#2013)

* Implement better error handling

* test

* Simplify struct name

* make test a bit mor readable

* fix formatting issues

* info

* remove pleonasm

internal/clierror/cli_error.go

@@ -0,0 +1,50 @@
+package clierror
+
+import (
+	"fmt"
+	"os"
+)
+
+type Error struct {
+	Message string
+	Details string
+	Hints   []string
+}
+
+// Wrap adds a new message and hints to the error
+func (e *Error) Wrap(message string, hints []string) *Error {
+	newError := &Error{
+		Message: message,
+		Details: e.Message,
+		Hints:   append(hints, e.Hints...),
+	}
+
+	if e.Details != "" {
+		newError.Details = fmt.Sprintf("%s: %s", e.Message, e.Details)
+	}
+
+	return newError
+}
+
+func (e *Error) Print() {
+	fmt.Printf("%s\n", e.Error())
+}
+
+func (e *Error) PrintStderr() {
+	fmt.Fprintf(os.Stderr, "%s\n", e.Error())
+}
+
+// Error returns the error string, compatible with the error interface
+func (e Error) Error() string {
+	output := fmt.Sprintf("Error:\n  %s\n\n", e.Message)
+	if e.Details != "" {
+		output += fmt.Sprintf("Error Details:\n  %s\n\n", e.Details)
+	}
+	if len(e.Hints) > 0 {
+		output += "Hints:\n"
+		for _, hint := range e.Hints {
+			output += fmt.Sprintf("  - %s\n", hint)
+		}
+	}
+	return output
+}

internal/clierror/cli_error_test.go

@@ -0,0 +1,111 @@
+package clierror
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_CLIError_String(t *testing.T) {
+	tests := []struct {
+		name string
+		err  Error
+		want string
+	}{
+		{
+			name: "empty",
+			err:  Error{},
+			want: "Error:\n  \n\n",
+		},
+		{
+			name: "error",
+			err: Error{
+				Message: "error",
+			},
+			want: "Error:\n  error\n\n",
+		},
+		{
+			name: "error and details",
+			err: Error{
+				Message: "error",
+				Details: "details",
+			},
+			want: "Error:\n  error\n\nError Details:\n  details\n\n",
+		},
+		{
+			name: "error, details and hints",
+			err: Error{
+				Message: "error",
+				Details: "details",
+				Hints:   []string{"hint1", "hint2"},
+			},
+			want: "Error:\n  error\n\nError Details:\n  details\n\nHints:\n  - hint1\n  - hint2\n",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			assert.Equal(t, tt.want, tt.err.Error())
+		})
+	}
+}
+
+// test Wrap function
+func Test_CLIError_Wrap(t *testing.T) {
+	tests := []struct {
+		name    string
+		err     Error
+		message string
+		hints   []string
+		want    string
+	}{
+		{
+			name:    "Add to empty error",
+			err:     Error{},
+			message: "error",
+			want:    "Error:\n  error\n\n",
+		},
+		{
+			name:    "Add with hints to empty error",
+			err:     Error{},
+			message: "error",
+			hints:   []string{"hint1", "hint2"},
+			want:    "Error:\n  error\n\nHints:\n  - hint1\n  - hint2\n",
+		},
+		{
+			name: "add to error",
+			err: Error{
+				Message: "error",
+			},
+			message: "error",
+			hints:   []string{"hint1", "hint2"},
+			want:    "Error:\n  error\n\nError Details:\n  error\n\nHints:\n  - hint1\n  - hint2\n",
+		},
+		{
+			name: "add to error with details",
+			err: Error{
+				Message: "previous",
+				Details: "details",
+			},
+			message: "error",
+			hints:   []string{"hint1", "hint2"},
+			want:    "Error:\n  error\n\nError Details:\n  previous: details\n\nHints:\n  - hint1\n  - hint2\n",
+		},
+		{
+			name: "add to error with details and hints",
+			err: Error{
+				Message: "previous",
+				Details: "details",
+				Hints:   []string{"hint1", "hint2"},
+			},
+			message: "error",
+			hints:   []string{"hint3", "hint4"},
+			want:    "Error:\n  error\n\nError Details:\n  previous: details\n\nHints:\n  - hint3\n  - hint4\n  - hint1\n  - hint2\n",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := tt.err.Wrap(tt.message, tt.hints)
+			assert.Equal(t, tt.want, err.Error())
+		})
+	}
+}

internal/cmd/kyma.go

@@ -12,7 +12,8 @@ func NewKymaCMD() *cobra.Command {
 		Use: "kyma",
 
 		// Affects children as well
-		SilenceErrors: false,
+		// by default Cobra adds `Error:` to the front of the error message, we want to supress it
+		SilenceErrors: true,
 		SilenceUsage:  true,
 		Run: func(cmd *cobra.Command, _ []string) {
 			if err := cmd.Help(); err != nil {

internal/cmd/provision/provision.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/kyma-project/cli.v3/internal/btp/auth"
 	"github.com/kyma-project/cli.v3/internal/btp/cis"
+	"github.com/kyma-project/cli.v3/internal/clierror"
 	"github.com/spf13/cobra"
 )
 
@@ -46,7 +47,11 @@ func runProvision(config *provisionConfig) error {
 	// TODO: is the credentials a good name for this field? it contains much more than credentials only
 	credentials, err := auth.LoadCISCredentials(config.credentialsPath)
 	if err != nil {
-		return fmt.Errorf("failed to load credentials from '%s' file: %s", config.credentialsPath, err.Error())
+		return clierror.Error{
+			Message: "failed to load credentials",
+			Details: err.Error(),
+			Hints:   []string{"Make sure the path to the credentials file is correct."},
+		}
 	}
 
 	token, err := auth.GetOAuthToken(

main.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"fmt"
 	"os"
 
 	"github.com/kyma-project/cli.v3/internal/cmd"
@@ -10,6 +11,7 @@ func main() {
 	cmd := cmd.NewKymaCMD()
 
 	if err := cmd.Execute(); err != nil {
+		fmt.Println(err.Error())
 		os.Exit(1)
 	}
 }