terminal: Use go-colorable

Add fallback to display colors on Windows.

terminal/terminal.go

@@ -28,6 +28,7 @@ type Term struct {
 	line     *liner.State
 	cmds     *Commands
 	dumb     bool
+	stdout   io.Writer
 	InitFile string
 }
 
@@ -37,12 +38,23 @@ func New(client service.Client, conf *config.Config) *Term {
 	if conf != nil && conf.Aliases != nil {
 		cmds.Merge(conf.Aliases)
 	}
+
+	var w io.Writer
+
+	dumb := strings.ToLower(os.Getenv("TERM")) == "dumb"
+	if dumb {
+		w = os.Stdout
+	} else {
+		w = getColorableWriter()
+	}
+
 	return &Term{
 		prompt: "(dlv) ",
 		line:   liner.NewLiner(),
 		client: client,
 		cmds:   cmds,
-		dumb:   !supportsEscapeCodes(),
+		dumb:   dumb,
+		stdout: w,
 	}
 }
 
@@ -134,7 +146,7 @@ func (t *Term) Println(prefix, str string) {
 	if !t.dumb {
 		prefix = fmt.Sprintf("%s%s%s", terminalBlueEscapeCode, prefix, terminalResetEscapeCode)
 	}
-	fmt.Printf("%s%s\n", prefix, str)
+	fmt.Fprintf(t.stdout, "%s%s\n", prefix, str)
 }
 
 func (t *Term) promptForInput() (string, error) {

terminal/terminal_other.go

@@ -3,11 +3,12 @@
 package terminal
 
 import (
+	"io"
 	"os"
-	"strings"
 )
 
-// supportsEscapeCodes returns true if console handles escape codes.
-func supportsEscapeCodes() bool {
-	return strings.ToLower(os.Getenv("TERM")) != "dumb"
+// getColorableWriter returns two values. First is Writer supported colors.
+// If return nil, colors will be disabled.
+func getColorableWriter() io.Writer {
+	return os.Stdout
 }

terminal/terminal_windows.go

@@ -1,31 +1,35 @@
 package terminal
 
 import (
+	"io"
 	"os"
 	"strings"
 	"syscall"
+
+	"github.com/mattn/go-colorable"
 )
 
-// supportsEscapeCodes returns true if console handles escape codes.
-func supportsEscapeCodes() bool {
-	if strings.ToLower(os.Getenv("TERM")) == "dumb" {
-		return false
-	}
+// getColorableWriter returns two values. First is Writer supported colors.
+// If return nil, colors will be disabled.
+func getColorableWriter() io.Writer {
 	if strings.ToLower(os.Getenv("ConEmuANSI")) == "on" {
 		// The ConEmu terminal is installed. Use it.
-		return true
+		return os.Stdout
 	}
 
 	const ENABLE_VIRTUAL_TERMINAL_PROCESSING = 0x0004
 
 	h, err := syscall.GetStdHandle(syscall.STD_OUTPUT_HANDLE)
 	if err != nil {
-		return false
+		return os.Stdout
 	}
 	var m uint32
 	err = syscall.GetConsoleMode(h, &m)
 	if err != nil {
-		return false
+		return os.Stdout
 	}
-	return m&ENABLE_VIRTUAL_TERMINAL_PROCESSING != 0
+	if m&ENABLE_VIRTUAL_TERMINAL_PROCESSING != 0 {
+		return os.Stdout
+	}
+	return colorable.NewColorableStdout()
 }