Use virtual terminal processing on Windows

password.go

@@ -5,7 +5,6 @@ import (
 	"strings"
 
 	"github.com/AlecAivazis/survey/v2/core"
-	"github.com/AlecAivazis/survey/v2/terminal"
 )
 
 /*
@@ -48,7 +47,7 @@ func (p *Password) Prompt(config *PromptConfig) (interface{}, error) {
 		return "", err
 	}
 
-	if _, err := fmt.Fprint(terminal.NewAnsiStdout(p.Stdio().Out), userOut); err != nil {
+	if _, err := fmt.Fprint(p.Stdio().Out, userOut); err != nil {
 		return "", err
 	}
 

renderer.go

@@ -3,6 +3,7 @@ package survey
 import (
 	"bytes"
 	"fmt"
+
 	"github.com/AlecAivazis/survey/v2/core"
 	"github.com/AlecAivazis/survey/v2/terminal"
 	"golang.org/x/term"
@@ -59,7 +60,7 @@ func (r *Renderer) Error(config *PromptConfig, invalid error) error {
 	}
 
 	// send the message to the user
-	if _, err := fmt.Fprint(terminal.NewAnsiStdout(r.stdio.Out), userOut); err != nil {
+	if _, err := fmt.Fprint(r.stdio.Out, userOut); err != nil {
 		return err
 	}
 
@@ -90,7 +91,7 @@ func (r *Renderer) Render(tmpl string, data interface{}) error {
 	}
 
 	// print the summary
-	if _, err := fmt.Fprint(terminal.NewAnsiStdout(r.stdio.Out), userOut); err != nil {
+	if _, err := fmt.Fprint(r.stdio.Out, userOut); err != nil {
 		return err
 	}
 

survey.go

@@ -10,16 +10,12 @@ import (
 
 	"github.com/AlecAivazis/survey/v2/core"
 	"github.com/AlecAivazis/survey/v2/terminal"
+	"github.com/mattn/go-colorable"
 )
 
 // DefaultAskOptions is the default options on ask, using the OS stdio.
 func defaultAskOptions() *AskOptions {
 	return &AskOptions{
-		Stdio: terminal.Stdio{
-			In:  os.Stdin,
-			Out: os.Stdout,
-			Err: os.Stderr,
-		},
 		PromptConfig: PromptConfig{
 			PageSize:     7,
 			HelpInput:    "?",
@@ -154,7 +150,7 @@ type AskOptions struct {
 func WithStdio(in terminal.FileReader, out terminal.FileWriter, err io.Writer) AskOpt {
 	return func(options *AskOptions) error {
 		options.Stdio.In = in
-		options.Stdio.Out = out
+		options.Stdio.Out = colorableOut(out)
 		options.Stdio.Err = err
 		return nil
 	}
@@ -323,6 +319,17 @@ func Ask(qs []*Question, response interface{}, opts ...AskOpt) error {
 		}
 	}
 
+	// fallback values in case [WithStdio] was not used
+	if options.Stdio.In == nil {
+		options.Stdio.In = os.Stdin
+	}
+	if options.Stdio.Out == nil {
+		options.Stdio.Out = colorableOut(os.Stdout)
+	}
+	if options.Stdio.Err == nil {
+		options.Stdio.Err = os.Stderr
+	}
+
 	// if we weren't passed a place to record the answers
 	if response == nil {
 		// we can't go any further
@@ -472,3 +479,34 @@ func computeCursorOffset(tmpl string, data IterableOpts, opts []core.OptionAnswe
 
 	return offset
 }
+
+// colorableOut transforms a file writer into one where it is safe to write ANSI escape codes to.
+func colorableOut(w terminal.FileWriter) terminal.FileWriter {
+	if f, ok := w.(*os.File); ok {
+		out := colorable.NewColorable(f)
+		if f, ok := out.(*os.File); ok {
+			// Most cases will end up here: the writer is either
+			// 1. the original os.Stdout; or
+			// 2. the original os.Stdout with virtual terminal processing enabled on Windows.
+			return f
+		}
+		// If we have reached this point, the resulting writer is a Windows-specific writer that
+		// converts ANSI escape codes to Console API calls, and we need to wrap it in an extra
+		// type to preserve the original file descriptor.
+		return &writerWithFd{
+			Writer: out,
+			orig:   f,
+		}
+	}
+	return w
+}
+
+// writerWithFd implements a [terminal.FileWriter]
+type writerWithFd struct {
+	io.Writer
+	orig *os.File
+}
+
+func (w writerWithFd) Fd() uintptr {
+	return w.orig.Fd()
+}

terminal/cursor.go

@@ -1,6 +1,3 @@
-//go:build !windows
-// +build !windows
-
 package terminal
 
 import (

terminal/display.go

@@ -1,9 +1,19 @@
 package terminal
 
+import (
+	"fmt"
+	"io"
+)
+
 type EraseLineMode int
 
 const (
 	ERASE_LINE_END EraseLineMode = iota
 	ERASE_LINE_START
 	ERASE_LINE_ALL
 )
+
+func EraseLine(out io.Writer, mode EraseLineMode) error {
+	_, err := fmt.Fprintf(out, "\x1b[%dK", mode)
+	return err
+}

terminal/output.go

@@ -7,14 +7,16 @@ import (
 	"io"
 )
 
-// NewAnsiStdout returns special stdout, which converts escape sequences to Windows API calls
-// on Windows environment.
+// NewAnsiStdout returns a writer connected to standard output that interprets ANSI escape codes to in a platform-agnostic way.
+//
+// Deprecated: use the mattn/go-colorable module instead of this method.
 func NewAnsiStdout(out FileWriter) io.Writer {
 	return out
 }
 
-// NewAnsiStderr returns special stderr, which converts escape sequences to Windows API calls
-// on Windows environment.
+// NewAnsiStdout returns a writer connected to standard error that interprets ANSI escape codes to in a platform-agnostic way.
+//
+// Deprecated: use the mattn/go-colorable module instead of this method.
 func NewAnsiStderr(out FileWriter) io.Writer {
 	return out
 }