enable color by default if stdout is a TTY (#9)

* enable color by default if stdout is a TTY

* --color -> --no-color

* Revert "--color -> --no-color"

This reverts commit a9105a6.

cmd/root.go

@@ -10,6 +10,7 @@ import (
 	"github.com/spf13/viper"
 
 	"github.com/svixhq/svix-cli/config"
+	"github.com/svixhq/svix-cli/utils"
 	"github.com/svixhq/svix-cli/version"
 	svix "github.com/svixhq/svix-libs/go"
 )
@@ -35,7 +36,10 @@ func init() {
 	rootCmd.Flags().BoolP("version", "v", false, "Get the version of the Svix CLI") // overrides default msg
 
 	// Global Flags
-	rootCmd.PersistentFlags().Bool("color", false, "colorize output json")
+	isTTY, _, err := utils.IsTTY(os.Stdout)
+	fmt.Fprintln(os.Stderr, isTTY)
+	cobra.CheckErr(err)
+	rootCmd.PersistentFlags().Bool("color", isTTY, "colorize output json")              // on by default if TTY, off if not
 	cobra.CheckErr(viper.BindPFlag("color", rootCmd.PersistentFlags().Lookup("color"))) // allow color flag to be set in config
 
 	// Register Commands

utils/pipe.go

@@ -7,16 +7,11 @@ import (
 )
 
 func IsPipeWithData(f *os.File) (bool, error) {
-	info, err := f.Stat()
+	isTTY, hasData, err := IsTTY(f)
 	if err != nil {
 		return false, err
 	}
-
-	if info.Mode()&os.ModeCharDevice != 0 || // stdin is not a Unix character device
-		info.Size() <= 0 { // stdin has no bytes
-		return false, nil
-	}
-	return true, nil
+	return !isTTY && hasData, nil
 }
 
 func ReadPipe() ([]byte, error) {
@@ -33,3 +28,14 @@ func ReadPipe() ([]byte, error) {
 	}
 	return []byte{}, nil
 }
+
+func IsTTY(f *os.File) (isTTY bool, hasBytes bool, err error) {
+	info, err := f.Stat()
+	if err != nil {
+		return false, false, err
+	}
+
+	isTTY = info.Mode()&os.ModeCharDevice != 0
+	hasBytes = info.Size() > 0
+	return isTTY, hasBytes, nil
+}