Merge pull request cli#126 from github/cygwin-color

mislav · web-flow · commit 9a3b032fface · 2019-11-28T11:59:51.000+01:00
Fix color output to Git Bash
diff --git a/utils/color.go b/utils/color.go
@@ -9,6 +9,18 @@ import (
 	"github.com/mgutz/ansi"
 )
 
+var _isStdoutTerminal = false
+var checkedTerminal = false
+
+func isStdoutTerminal() bool {
+	if !checkedTerminal {
+		fd := os.Stdout.Fd()
+		_isStdoutTerminal = isatty.IsTerminal(fd) || isatty.IsCygwinTerminal(fd)
+		checkedTerminal = true
+	}
+	return _isStdoutTerminal
+}
+
 // NewColorable returns an output stream that handles ANSI color sequences on Windows
 func NewColorable(f *os.File) io.Writer {
 	return colorable.NewColorable(f)
@@ -17,18 +29,33 @@ func NewColorable(f *os.File) io.Writer {
 func makeColorFunc(color string) func(string) string {
 	cf := ansi.ColorFunc(color)
 	return func(arg string) string {
-		if isatty.IsTerminal(os.Stdout.Fd()) {
+		if isStdoutTerminal() {
 			return cf(arg)
 		}
 		return arg
 	}
 }
 
+// Magenta outputs ANSI color if stdout is a tty
 var Magenta = makeColorFunc("magenta")
+
+// Cyan outputs ANSI color if stdout is a tty
 var Cyan = makeColorFunc("cyan")
+
+// Red outputs ANSI color if stdout is a tty
 var Red = makeColorFunc("red")
+
+// Yellow outputs ANSI color if stdout is a tty
 var Yellow = makeColorFunc("yellow")
+
+// Blue outputs ANSI color if stdout is a tty
 var Blue = makeColorFunc("blue")
+
+// Green outputs ANSI color if stdout is a tty
 var Green = makeColorFunc("green")
+
+// Gray outputs ANSI color if stdout is a tty
 var Gray = makeColorFunc("black+h")
+
+// Bold outputs ANSI color if stdout is a tty
 var Bold = makeColorFunc("default+b")
