cli · mislav · Sep 16, 2020 · Sep 4, 2020 · Sep 7, 2020 · Sep 7, 2020
@@ -10,6 +10,7 @@ import (
 	"path"
 	"strings"
 
+	surveyCore "github.com/AlecAivazis/survey/v2/core"
 	"github.com/cli/cli/api"
 	"github.com/cli/cli/command"
 	"github.com/cli/cli/internal/config"
@@ -43,6 +44,23 @@ func main() {
 
 	cmdFactory := factory.New(command.Version)
 	stderr := cmdFactory.IOStreams.ErrOut
+	if !cmdFactory.IOStreams.ColorEnabled() {
+		surveyCore.DisableColor = true
+	} else {
+		// override survey's poor choice of color
+		surveyCore.TemplateFuncsWithColor["color"] = func(style string) string {
+			switch style {
+			case "white":
+				if cmdFactory.IOStreams.ColorSupport256() {
+					return fmt.Sprintf("\x1b[%d;5;%dm", 38, 242)
+				}
+				return ansi.ColorCode("default")
+			default:
+				return ansi.ColorCode(style)
+			}
+		}
+	}
+
 	rootCmd := root.NewCmdRoot(cmdFactory, command.Version, command.BuildDate)
 
 	cfg, err := cmdFactory.Config()

@@ -28,12 +28,17 @@ func NewHelpTopic(topic string) *cobra.Command {
 		DEBUG: set to any value to enable verbose output to standard error. Include values "api"
 		or "oauth" to print detailed information about HTTP requests or authentication flow.
 
-		PAGER: a paging program to send standard output to, e.g. "less".
+		PAGER: a terminal paging program to send standard output to, e.g. "less".
 
 		GLAMOUR_STYLE: the style to use for rendering Markdown. See
 		https://github.com/charmbracelet/glamour#styles
 
-		NO_COLOR: avoid printing ANSI escape sequences for color output.
+		NO_COLOR: set to any value to avoid printing ANSI escape sequences for color output.
+
+		CLICOLOR: set to "0" to disable printing ANSI colors in output.
+
+		CLICOLOR_FORCE: set to a value other than "0" to keep ANSI colors in output
+		even when the output is piped.
 	`)
 
 	cmd := &cobra.Command{

@@ -1,6 +1,12 @@
 package iostreams
 
-import "github.com/mgutz/ansi"
+import (
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/mgutz/ansi"
+)
 
 var (
 	magenta = ansi.ColorFunc("magenta")
@@ -11,14 +17,42 @@ var (
 	green   = ansi.ColorFunc("green")
 	gray    = ansi.ColorFunc("black+h")
 	bold    = ansi.ColorFunc("default+b")
+
+	gray256 = func(t string) string {
+		return fmt.Sprintf("\x1b[%d;5;%dm%s\x1b[m", 38, 242, t)
+	}
 )
 
-func NewColorScheme(enabled bool) *ColorScheme {
-	return &ColorScheme{enabled: enabled}
+func EnvColorDisabled() bool {
+	return os.Getenv("NO_COLOR") != "" || os.Getenv("CLICOLOR") == "0"
+}
+
+func EnvColorForced() bool {
+	return os.Getenv("CLICOLOR_FORCE") != "" && os.Getenv("CLICOLOR_FORCE") != "0"
+}
+
+func Is256ColorSupported() bool {
+	term := os.Getenv("TERM")
+	colorterm := os.Getenv("COLORTERM")
+
+	return strings.Contains(term, "256") ||
+		strings.Contains(term, "24bit") ||
+		strings.Contains(term, "truecolor") ||
+		strings.Contains(colorterm, "256") ||
+		strings.Contains(colorterm, "24bit") ||
+		strings.Contains(colorterm, "truecolor")
+}
+
+func NewColorScheme(enabled, is256enabled bool) *ColorScheme {
+	return &ColorScheme{
+		enabled:      enabled,
+		is256enabled: is256enabled,
+	}
 }
 
 type ColorScheme struct {
-	enabled bool
+	enabled      bool
+	is256enabled bool
 }
 
 func (c *ColorScheme) Bold(t string) string {
@@ -53,6 +87,9 @@ func (c *ColorScheme) Gray(t string) string {
 	if !c.enabled {
 		return t
 	}
+	if c.is256enabled {
+		return gray256(t)
+	}
 	return gray(t)
 }
 

@@ -0,0 +1,145 @@
+package iostreams
+
+import (
+	"os"
+	"testing"
+)
+
+func TestEnvColorDisabled(t *testing.T) {
+	orig_NO_COLOR := os.Getenv("NO_COLOR")
+	orig_CLICOLOR := os.Getenv("CLICOLOR")
+	orig_CLICOLOR_FORCE := os.Getenv("CLICOLOR_FORCE")
+	t.Cleanup(func() {
+		os.Setenv("NO_COLOR", orig_NO_COLOR)
+		os.Setenv("CLICOLOR", orig_CLICOLOR)
+		os.Setenv("CLICOLOR_FORCE", orig_CLICOLOR_FORCE)
+	})
+
+	tests := []struct {
+		name           string
+		NO_COLOR       string
+		CLICOLOR       string
+		CLICOLOR_FORCE string
+		want           bool
+	}{
+		{
+			name:           "pristine env",
+			NO_COLOR:       "",
+			CLICOLOR:       "",
+			CLICOLOR_FORCE: "",
+			want:           false,
+		},
+		{
+			name:           "NO_COLOR enabled",
+			NO_COLOR:       "1",
+			CLICOLOR:       "",
+			CLICOLOR_FORCE: "",
+			want:           true,
+		},
+		{
+			name:           "CLICOLOR disabled",
+			NO_COLOR:       "",
+			CLICOLOR:       "0",
+			CLICOLOR_FORCE: "",
+			want:           true,
+		},
+		{
+			name:           "CLICOLOR enabled",
+			NO_COLOR:       "",
+			CLICOLOR:       "1",
+			CLICOLOR_FORCE: "",
+			want:           false,
+		},
+		{
+			name:           "CLICOLOR_FORCE has no effect",
+			NO_COLOR:       "",
+			CLICOLOR:       "",
+			CLICOLOR_FORCE: "1",
+			want:           false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			os.Setenv("NO_COLOR", tt.NO_COLOR)
+			os.Setenv("CLICOLOR", tt.CLICOLOR)
+			os.Setenv("CLICOLOR_FORCE", tt.CLICOLOR_FORCE)
+
+			if got := EnvColorDisabled(); got != tt.want {
+				t.Errorf("EnvColorDisabled(): want %v, got %v", tt.want, got)
+			}
+		})
+	}
+}
+
+func TestEnvColorForced(t *testing.T) {
+	orig_NO_COLOR := os.Getenv("NO_COLOR")
+	orig_CLICOLOR := os.Getenv("CLICOLOR")
+	orig_CLICOLOR_FORCE := os.Getenv("CLICOLOR_FORCE")
+	t.Cleanup(func() {
+		os.Setenv("NO_COLOR", orig_NO_COLOR)
+		os.Setenv("CLICOLOR", orig_CLICOLOR)
+		os.Setenv("CLICOLOR_FORCE", orig_CLICOLOR_FORCE)
+	})
+
+	tests := []struct {
+		name           string
+		NO_COLOR       string
+		CLICOLOR       string
+		CLICOLOR_FORCE string
+		want           bool
+	}{
+		{
+			name:           "pristine env",
+			NO_COLOR:       "",
+			CLICOLOR:       "",
+			CLICOLOR_FORCE: "",
+			want:           false,
+		},
+		{
+			name:           "NO_COLOR enabled",
+			NO_COLOR:       "1",
+			CLICOLOR:       "",
+			CLICOLOR_FORCE: "",
+			want:           false,
+		},
+		{
+			name:           "CLICOLOR disabled",
+			NO_COLOR:       "",
+			CLICOLOR:       "0",
+			CLICOLOR_FORCE: "",
+			want:           false,
+		},
+		{
+			name:           "CLICOLOR enabled",
+			NO_COLOR:       "",
+			CLICOLOR:       "1",
+			CLICOLOR_FORCE: "",
+			want:           false,
+		},
+		{
+			name:           "CLICOLOR_FORCE enabled",
+			NO_COLOR:       "",
+			CLICOLOR:       "",
+			CLICOLOR_FORCE: "1",
+			want:           true,
+		},
+		{
+			name:           "CLICOLOR_FORCE disabled",
+			NO_COLOR:       "",
+			CLICOLOR:       "",
+			CLICOLOR_FORCE: "0",
+			want:           false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			os.Setenv("NO_COLOR", tt.NO_COLOR)
+			os.Setenv("CLICOLOR", tt.CLICOLOR)
+			os.Setenv("CLICOLOR_FORCE", tt.CLICOLOR_FORCE)
+
+			if got := EnvColorForced(); got != tt.want {
+				t.Errorf("EnvColorForced(): want %v, got %v", tt.want, got)
+			}
+		})
+	}
+}
@@ -26,6 +26,7 @@ type IOStreams struct {
 	// the original (non-colorable) output stream
 	originalOut  io.Writer
 	colorEnabled bool
+	is256enabled bool
 
 	progressIndicatorEnabled bool
 	progressIndicator        *spinner.Spinner
@@ -47,6 +48,10 @@ func (s *IOStreams) ColorEnabled() bool {
 	return s.colorEnabled
 }
 
+func (s *IOStreams) ColorSupport256() bool {
+	return s.is256enabled
+}
+
 func (s *IOStreams) SetStdinTTY(isTTY bool) {
 	s.stdinTTYOverride = true
 	s.stdinIsTTY = isTTY
@@ -200,7 +205,7 @@ func (s *IOStreams) TerminalWidth() int {
 }
 
 func (s *IOStreams) ColorScheme() *ColorScheme {
-	return NewColorScheme(s.ColorEnabled())
+	return NewColorScheme(s.ColorEnabled(), s.ColorSupport256())
 }
 
 func System() *IOStreams {
@@ -212,7 +217,8 @@ func System() *IOStreams {
 		originalOut:  os.Stdout,
 		Out:          colorable.NewColorable(os.Stdout),
 		ErrOut:       colorable.NewColorable(os.Stderr),
-		colorEnabled: os.Getenv("NO_COLOR") == "" && stdoutIsTTY,
+		colorEnabled: EnvColorForced() || (!EnvColorDisabled() && stdoutIsTTY),
+		is256enabled: Is256ColorSupported(),
 		pagerCommand: os.Getenv("PAGER"),
 	}
 

@@ -1,9 +1,11 @@
 package utils
 
 import (
+	"fmt"
 	"io"
 	"os"
 
+	"github.com/cli/cli/pkg/iostreams"
 	"github.com/mattn/go-colorable"
 	"github.com/mgutz/ansi"
 )
@@ -32,14 +34,21 @@ func makeColorFunc(color string) func(string) string {
 	cf := ansi.ColorFunc(color)
 	return func(arg string) string {
 		if isColorEnabled() {
+			if color == "black+h" && iostreams.Is256ColorSupported() {
+				return fmt.Sprintf("\x1b[%d;5;%dm%s\x1b[m", 38, 242, arg)
+			}
 			return cf(arg)
 		}
 		return arg
 	}
 }
 
 func isColorEnabled() bool {
-	if os.Getenv("NO_COLOR") != "" {
+	if iostreams.EnvColorForced() {
+		return true
+	}
+
+	if iostreams.EnvColorDisabled() {
 		return false
 	}