new Errorln method and add comments

cmd/ghcs/output/logger.go

@@ -5,6 +5,8 @@ import (
 	"io"
 )
 
+// NewLogger returns a Logger that will write to the given stdout/stderr writers.
+// Disable the Logger to prevent it from writing to stdout in a TTY environment.
 func NewLogger(stdout, stderr io.Writer, disabled bool) *Logger {
 	return &Logger{
 		out:     stdout,
@@ -13,12 +15,16 @@ func NewLogger(stdout, stderr io.Writer, disabled bool) *Logger {
 	}
 }
 
+// Logger writes to the given stdout/stderr writers.
+// If not enabled, Print functions will noop but Error functions will continue
+// to write to the stderr writer.
 type Logger struct {
 	out     io.Writer
 	errout  io.Writer
 	enabled bool
 }
 
+// Print writes the arguments to the stdout writer.
 func (l *Logger) Print(v ...interface{}) (int, error) {
 	if !l.enabled {
 		return 0, nil
@@ -26,6 +32,7 @@ func (l *Logger) Print(v ...interface{}) (int, error) {
 	return fmt.Fprint(l.out, v...)
 }
 
+// Println writes the arguments to the stdout writer with a newline at the end.
 func (l *Logger) Println(v ...interface{}) (int, error) {
 	if !l.enabled {
 		return 0, nil
@@ -33,6 +40,7 @@ func (l *Logger) Println(v ...interface{}) (int, error) {
 	return fmt.Fprintln(l.out, v...)
 }
 
+// Printf writes the formatted arguments to the stdout writer.
 func (l *Logger) Printf(f string, v ...interface{}) (int, error) {
 	if !l.enabled {
 		return 0, nil
@@ -40,6 +48,12 @@ func (l *Logger) Printf(f string, v ...interface{}) (int, error) {
 	return fmt.Fprintf(l.out, f, v...)
 }
 
+// Errorf writes the formatted arguments to the stderr writer.
 func (l *Logger) Errorf(f string, v ...interface{}) (int, error) {
 	return fmt.Fprintf(l.errout, f, v...)
 }
+
+// Errorln writes the arguments to the stderr writer with a newline at the end.
+func (l *Logger) Errorln(v ...interface{}) (int, error) {
+	return fmt.Fprintln(l.errout, v...)
+}