packer: ColoredUi

packer/ui.go

@@ -6,6 +6,17 @@ import (
 	"log"
 )
 
+type UiColor uint
+
+const (
+	UiColorRed     UiColor = 31
+	UiColorGreen           = 32
+	UiColorYellow          = 33
+	UiColorBlue            = 34
+	UiColorMagenta         = 35
+	UiColorCyan            = 36
+)
+
 // The Ui interface handles all communication for Packer with the outside
 // world. This sort of control allows us to strictly control how output
 // is formatted and various levels of output.
@@ -15,6 +26,12 @@ type Ui interface {
 	Error(string)
 }
 
+// ColoredUi is a UI that is colored using terminal colors.
+type ColoredUi struct {
+	Color UiColor
+	Ui    Ui
+}
+
 // PrefixedUi is a UI that wraps another UI implementation and adds a
 // prefix to all the messages going out.
 type PrefixedUi struct {
@@ -30,6 +47,22 @@ type ReaderWriterUi struct {
 	Writer io.Writer
 }
 
+func (u *ColoredUi) Say(message string) {
+	u.Ui.Say(u.colorize(message))
+}
+
+func (u *ColoredUi) Message(message string) {
+	u.Ui.Message(u.colorize(message))
+}
+
+func (u *ColoredUi) Error(message string) {
+	u.Ui.Error(u.colorize(message))
+}
+
+func (u *ColoredUi) colorize(message string) string {
+	return fmt.Sprintf("\033[0;%d;40m%s\033[0m", u.Color, message)
+}
+
 func (u *PrefixedUi) Say(message string) {
 	u.Ui.Say(fmt.Sprintf("%s: %s", u.SayPrefix, message))
 }

packer/ui_test.go

@@ -13,6 +13,16 @@ func testUi() *ReaderWriterUi {
 	}
 }
 
+func TestColoredUi(t *testing.T) {
+	assert := asserts.NewTestingAsserts(t, true)
+
+	bufferUi := testUi()
+	ui := &ColoredUi{UiColorRed, bufferUi}
+
+	ui.Say("foo")
+	assert.Equal(readWriter(bufferUi), "\033[0;31;40mfoo\033[0m\n", "should have color")
+}
+
 func TestPrefixedUi(t *testing.T) {
 	assert := asserts.NewTestingAsserts(t, true)
 
@@ -29,6 +39,14 @@ func TestPrefixedUi(t *testing.T) {
 	assert.Equal(readWriter(bufferUi), "mitchell: bar\n", "should have prefix")
 }
 
+func TestColoredUi_ImplUi(t *testing.T) {
+	var raw interface{}
+	raw = &ColoredUi{}
+	if _, ok := raw.(Ui); !ok {
+		t.Fatalf("ColoredUi must implement Ui")
+	}
+}
+
 func TestPrefixedUi_ImplUi(t *testing.T) {
 	var raw interface{}
 	raw = &PrefixedUi{}