fix: handle nil role and permissions lists in role commands

internal/cli/roles.go

@@ -87,6 +87,9 @@ func listRolesCmd(cli *cli) *cobra.Command {
 					if err != nil {
 						return nil, false, err
 					}
+					if roleList == nil {
+						return result, false, nil
+					}
 
 					for _, role := range roleList.Roles {
 						result = append(result, role)
@@ -350,6 +353,10 @@ func (c *cli) rolePickerOptions(ctx context.Context) (pickerOptions, error) {
 
 	var opts pickerOptions
 
+	if list == nil {
+		return nil, errors.New("there are currently no roles to choose from. Create one by running: `auth0 roles create`")
+	}
+
 	for _, c := range list.Roles {
 		value := c.GetID()
 		label := fmt.Sprintf("%s %s", c.GetName(), ansi.Faint("("+value+")"))

internal/cli/roles_permissions.go

@@ -91,6 +91,9 @@ func listRolePermissionsCmd(cli *cli) *cobra.Command {
 					if err != nil {
 						return nil, false, err
 					}
+					if permissionsList == nil {
+						return result, false, nil
+					}
 
 					for _, role := range permissionsList.Permissions {
 						result = append(result, role)

internal/cli/roles_test.go

@@ -3,6 +3,7 @@ package cli
 import (
 	"context"
 	"errors"
+	"io"
 	"testing"
 
 	"github.com/auth0/go-auth0/management"
@@ -12,8 +13,50 @@ import (
 
 	"github.com/auth0/auth0-cli/internal/auth0"
 	"github.com/auth0/auth0-cli/internal/auth0/mock"
+	"github.com/auth0/auth0-cli/internal/display"
 )
 
+func TestListRolesCmd(t *testing.T) {
+	tests := []struct {
+		name     string
+		roleList *management.RoleList
+	}{
+		{
+			name:     "nil role list (no results)",
+			roleList: nil,
+		},
+		{
+			name:     "empty role list",
+			roleList: &management.RoleList{Roles: []*management.Role{}},
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			ctrl := gomock.NewController(t)
+			defer ctrl.Finish()
+
+			roleAPI := mock.NewMockRoleAPI(ctrl)
+			roleAPI.EXPECT().
+				List(gomock.Any(), gomock.Any(), gomock.Any()).
+				Return(test.roleList, nil)
+
+			cli := &cli{
+				renderer: &display.Renderer{
+					MessageWriter: io.Discard,
+					ResultWriter:  io.Discard,
+				},
+				api: &auth0.API{Role: roleAPI},
+			}
+
+			cmd := listRolesCmd(cli)
+			cmd.SetArgs([]string{})
+
+			assert.NoError(t, cmd.Execute())
+		})
+	}
+}
+
 func TestRolesPickerOptions(t *testing.T) {
 	tests := []struct {
 		name         string