feat(pin): add non-interactive mode for piped output environments

Author: yarlson

README.md

@@ -15,6 +15,7 @@
 - ✨ Ability to update the spinner message dynamically
 - ⚙️ No external dependencies – uses only the Go standard library
 - 🚀 Compatible with Go 1.11 and later
+- ⏹ Automatically disables animations in non-interactive (piped) environments to prevent output corruption
 
 ## Installation
 
@@ -35,6 +36,10 @@ defer cancel()
 p.Stop("Done!")
 ```
 
+## Non-interactive Behavior
+
+When the spinner detects that `stdout` is not connected to an interactive terminal (for example, when output is piped), it disables animations and prints only the final message. This prevents ANSI escape codes from cluttering the output.
+
 ## Examples
 
 ### Basic Progress Indicator

pin.go

@@ -39,6 +39,7 @@ package pin
 import (
 	"context"
 	"fmt"
+	"os"
 	"sync"
 	"time"
 )
@@ -194,7 +195,7 @@ func New(message string, opts ...Option) *Pin {
 	p := &Pin{
 		frames:          defaultFrames,
 		message:         message,
-		stopChan:        make(chan struct{}),
+		stopChan:        make(chan struct{}, 1),
 		spinnerColor:    ColorDefault,
 		textColor:       ColorDefault,
 		doneSymbol:      '✓',
@@ -219,6 +220,16 @@ func (p *Pin) Start(ctx context.Context) context.CancelFunc {
 	if p.isRunning {
 		return func() {}
 	}
+
+	if !isTerminal(os.Stdout) {
+		p.isRunning = true
+		go func() {
+			<-ctx.Done()
+			p.isRunning = false
+		}()
+		return func() {}
+	}
+
 	p.isRunning = true
 
 	ctx, cancel := context.WithCancel(ctx)
@@ -284,6 +295,13 @@ func (p *Pin) Stop(message ...string) {
 	if !p.isRunning {
 		return
 	}
+
+	if !isTerminal(os.Stdout) {
+		if len(message) > 0 {
+			fmt.Println(message[0])
+		}
+		return
+	}
 	p.isRunning = false
 	p.stopChan <- struct{}{}
 
@@ -366,3 +384,18 @@ func (c Color) getColorCode() string {
 		return ""
 	}
 }
+
+// isTerminal checks if the provided file descriptor is a terminal.
+func isTerminal(f *os.File) bool {
+	if ForceInteractive {
+		return true
+	}
+	fi, err := f.Stat()
+	if err != nil {
+		return false
+	}
+
+	return (fi.Mode() & os.ModeCharDevice) != 0
+}
+
+var ForceInteractive bool

pin_test.go

@@ -13,6 +13,10 @@ import (
 	"github.com/yarlson/pin"
 )
 
+func init() {
+	pin.ForceInteractive = true
+}
+
 var (
 	stdoutMu sync.Mutex
 )