commands: Extract some common types into its own file

See #4598

1 files changed, 62 insertions, 0 deletions

diff --git a/commands/helpers.go b/commands/helpers.go
new file mode 100644
index 000000000..78e549d22
--- /dev/null
+++ b/commands/helpers.go
@@ -0,0 +1,62 @@
+// Copyright 2018 The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package commands defines and implements command-line commands and flags
+// used by Hugo. Commands and flags are implemented using Cobra.
+package commands
+
+const (
+	ansiEsc    = "\u001B"
+	clearLine  = "\r\033[K"
+	hideCursor = ansiEsc + "[?25l"
+	showCursor = ansiEsc + "[?25h"
+)
+
+// commandError is an error used to signal different error situations in command handling.
+type commandError struct {
+	s         string
+	userError bool
+}
+
+func (c commandError) Error() string {
+	return c.s
+}
+
+func (c commandError) isUserError() bool {
+	return c.userError
+}
+
+func newUserError(a ...interface{}) commandError {
+	return commandError{s: fmt.Sprintln(a...), userError: true}
+}
+
+func newSystemError(a ...interface{}) commandError {
+	return commandError{s: fmt.Sprintln(a...), userError: false}
+}
+
+func newSystemErrorF(format string, a ...interface{}) commandError {
+	return commandError{s: fmt.Sprintf(format, a...), userError: false}
+}
+
+// Catch some of the obvious user errors from Cobra.
+// We don't want to show the usage message for every error.
+// The below may be to generic. Time will show.
+var userErrorRegexp = regexp.MustCompile("argument|flag|shorthand")
+
+func isUserError(err error) bool {
+	if cErr, ok := err.(commandError); ok && cErr.isUserError() {
+		return true
+	}
+
+	return userErrorRegexp.MatchString(err.Error())
+}