Add column for listing the label color (#5462)

Fixes #5448

pkg/cmd/label/list/list.go

@@ -8,6 +8,7 @@ import (
 	"github.com/cli/cli/v2/pkg/cmd/label/shared"
 	"github.com/cli/cli/v2/pkg/cmdutil"
 	"github.com/cli/cli/v2/pkg/iostreams"
+	"github.com/cli/cli/v2/pkg/text"
 	"github.com/cli/cli/v2/utils"
 	"github.com/spf13/cobra"
 )
@@ -101,15 +102,9 @@ func printLabels(io *iostreams.IOStreams, labels []shared.Label) error {
 	table := utils.NewTablePrinter(io)
 
 	for _, label := range labels {
-		labelName := ""
-		if table.IsTTY() {
-			labelName = cs.HexToRGB(label.Color, label.Name)
-		} else {
-			labelName = label.Name
-		}
-
-		table.AddField(labelName, nil, nil)
-		table.AddField(label.Description, nil, nil)
+		table.AddField(label.Name, nil, cs.ColorFromRGB(label.Color))
+		table.AddField(label.Description, text.Truncate, nil)
+		table.AddField("#"+label.Color, nil, nil)
 
 		table.EndRow()
 	}

pkg/cmd/label/list/list_test.go

@@ -120,7 +120,7 @@ func TestListRun(t *testing.T) {
 					),
 				)
 			},
-			wantStdout: "\nShowing 2 of 2 labels in OWNER/REPO\n\nbug   This is a bug label\ndocs  This is a docs label\n",
+			wantStdout: "\nShowing 2 of 2 labels in OWNER/REPO\n\nbug   This is a bug label   #d73a4a\ndocs  This is a docs label  #ffa8da\n",
 		},
 		{
 			name: "lists labels notty",
@@ -158,7 +158,7 @@ func TestListRun(t *testing.T) {
 					),
 				)
 			},
-			wantStdout: "bug\tThis is a bug label\ndocs\tThis is a docs label\n",
+			wantStdout: "bug\tThis is a bug label\t#d73a4a\ndocs\tThis is a docs label\t#ffa8da\n",
 		},
 		{
 			name: "empty label list",

pkg/iostreams/color.go

@@ -210,6 +210,15 @@ func (c *ColorScheme) ColorFromString(s string) func(string) string {
 	return fn
 }
 
+// ColorFromRGB returns a function suitable for TablePrinter.AddField
+// that calls HexToRGB, coloring text if supported by the terminal.
+func (c *ColorScheme) ColorFromRGB(hex string) func(string) string {
+	return func(s string) string {
+		return c.HexToRGB(hex, s)
+	}
+}
+
+// HexToRGB uses the given hex to color x if supported by the terminal.
 func (c *ColorScheme) HexToRGB(hex string, x string) string {
 	if !c.enabled || !c.hasTrueColor || len(hex) != 6 {
 		return x

pkg/iostreams/color_test.go

@@ -146,7 +146,51 @@ func TestEnvColorForced(t *testing.T) {
 	}
 }
 
-func Test_HextoRGB(t *testing.T) {
+func TestColorFromRGB(t *testing.T) {
+	tests := []struct {
+		name  string
+		hex   string
+		text  string
+		wants string
+		cs    *ColorScheme
+	}{
+		{
+			name:  "truecolor",
+			hex:   "fc0303",
+			text:  "red",
+			wants: "\033[38;2;252;3;3mred\033[0m",
+			cs:    NewColorScheme(true, true, true),
+		},
+		{
+			name:  "no truecolor",
+			hex:   "fc0303",
+			text:  "red",
+			wants: "red",
+			cs:    NewColorScheme(true, true, false),
+		},
+		{
+			name:  "no color",
+			hex:   "fc0303",
+			text:  "red",
+			wants: "red",
+			cs:    NewColorScheme(false, false, false),
+		},
+		{
+			name:  "invalid hex",
+			hex:   "fc0",
+			text:  "red",
+			wants: "red",
+			cs:    NewColorScheme(false, false, false),
+		},
+	}
+
+	for _, tt := range tests {
+		fn := tt.cs.ColorFromRGB(tt.hex)
+		assert.Equal(t, tt.wants, fn(tt.text))
+	}
+}
+
+func TestHexToRGB(t *testing.T) {
 	tests := []struct {
 		name  string
 		hex   string