feat: respect NO_COLOR environment variable

- Export IsTerminal() in jsonutils package as single source of truth
- Check NO_COLOR env var before terminal detection
- Update configs.go to use jsonutils.IsTerminal()
- Follows https://no-color.org/ standard

Author: natsirtguy

cmd/mcptools/commands/configs.go

@@ -9,8 +9,8 @@ import (
 	"sort"
 	"strings"
 
+	"github.com/f/mcptools/pkg/jsonutils"
 	"github.com/spf13/cobra"
-	"golang.org/x/term"
 	"golang.org/x/text/cases"
 	"golang.org/x/text/language"
 )
@@ -516,7 +516,7 @@ func formatColoredGroupedServers(servers []ServerConfig) string {
 
 	var buf bytes.Buffer
 	// Check if we're outputting to a terminal (for colors)
-	useColors := term.IsTerminal(int(os.Stdout.Fd()))
+	useColors := jsonutils.IsTerminal()
 
 	for _, source := range sourceOrder {
 		// Print source header with bold blue

pkg/jsonutils/jsonutils.go

@@ -37,8 +37,11 @@ const (
 	shortTypeArray  = "arr"
 )
 
-// isTerminal determines if stdout is a terminal (for colorized output).
-func isTerminal() bool {
+// IsTerminal reports whether stdout is a terminal and NO_COLOR is not set.
+func IsTerminal() bool {
+	if _, noColor := os.LookupEnv("NO_COLOR"); noColor {
+		return false
+	}
 	return term.IsTerminal(int(os.Stdout.Fd()))
 }
 
@@ -152,7 +155,7 @@ func formatToolsList(tools any) (string, error) {
 	termWidth := getTermWidth()
 	descIndent := "     " // 5 spaces for description indentation
 	descWidth := termWidth - len(descIndent)
-	useColors := isTerminal()
+	useColors := IsTerminal()
 
 	for i, t := range toolsSlice {
 		tool, ok1 := t.(map[string]any)
@@ -620,7 +623,7 @@ func formatResourcesList(resources any) (string, error) {
 
 	var buf bytes.Buffer
 	w := tabwriter.NewWriter(&buf, 0, 0, 2, ' ', 0)
-	useColors := isTerminal()
+	useColors := IsTerminal()
 
 	// NOTE: Ensure that the column headers are the same length,
 	//       including the color escape sequences!
@@ -685,7 +688,7 @@ func formatPromptsList(prompts any) (string, error) {
 	termWidth := getTermWidth()
 	descIndent := "     " // 5 spaces for description indentation
 	descWidth := termWidth - len(descIndent)
-	useColors := isTerminal()
+	useColors := IsTerminal()
 
 	for i, p := range promptsSlice {
 		prompt, ok1 := p.(map[string]any)
@@ -731,7 +734,7 @@ func formatContent(content any) (string, error) {
 	}
 
 	var buf strings.Builder
-	useColors := isTerminal()
+	useColors := IsTerminal()
 
 	for _, c := range contentSlice {
 		contentItem, ok1 := c.(map[string]any)
@@ -775,7 +778,7 @@ func formatGenericMap(data map[string]any) (string, error) {
 
 	var buf bytes.Buffer
 	w := tabwriter.NewWriter(&buf, 0, 0, 2, ' ', 0)
-	useColors := isTerminal()
+	useColors := IsTerminal()
 
 	if useColors {
 		fmt.Fprintf(w, "%sKEY%s\t%sVALUE%s\n",

pkg/jsonutils/jsonutils_test.go

@@ -504,3 +504,11 @@ func TestNormalizeParameterType(t *testing.T) {
 		})
 	}
 }
+
+func TestIsTerminal_NoColor(t *testing.T) {
+	// With NO_COLOR set, isTerminal should return false
+	t.Setenv("NO_COLOR", "1")
+	if IsTerminal() {
+		t.Error("IsTerminal() should return false when NO_COLOR is set")
+	}
+}