feat(cli): validate name length on template create (#3823)

* feat(cli): add template create validation test

This adds a test to validate that `template create` prints an error
message if called with a template name exceeding the 32-char limit.

* fixup

* fixup test

* feat(cli): add name validation to templatecreate

This adds a validation step to ensure the template name is less than 32
characters.

* fixup!: use utf8.RuneCountInString

* fixup!: remove pty from test

cli/templatecreate.go

@@ -6,6 +6,7 @@ import (
 	"path/filepath"
 	"strings"
 	"time"
+	"unicode/utf8"
 
 	"github.com/briandowns/spinner"
 	"github.com/spf13/cobra"
@@ -49,6 +50,10 @@ func templateCreate() *cobra.Command {
 				templateName = args[0]
 			}
 
+			if utf8.RuneCountInString(templateName) > 31 {
+				return xerrors.Errorf("Template name must be less than 32 characters")
+			}
+
 			_, err = client.TemplateByName(cmd.Context(), organization.ID, templateName)
 			if err == nil {
 				return xerrors.Errorf("A template already exists named %q!", templateName)