Refactor show command code logic

Move code logic into scaffold for consinstency.

Introduce test case for show command flag.

internal/cmd/root.go

@@ -42,15 +42,6 @@ var version string
 // saveToClipboard function will be implemented by OS specific code
 var saveToClipboard func(img.Scaffold) error
 
-// commandIndicator is the string to be used to indicate the command in the screenshot
-var commandIndicator = func() string {
-	if val, ok := os.LookupEnv("TS_COMMAND_INDICATOR"); ok {
-		return val
-	}
-
-	return "➜"
-}()
-
 var rootCmd = &cobra.Command{
 	Use:   fmt.Sprintf("%s [%s flags] [--] command [command flags] [command arguments] [...]", executableName(), executableName()),
 	Short: "Creates a screenshot of terminal command output",
@@ -111,11 +102,9 @@ window including all terminal colors and text decorations.
 		// Optional: Prepend command line arguments to output content
 		//
 		if includeCommand, err := cmd.Flags().GetBool("show-cmd"); err == nil && includeCommand {
-			// #nosec G104
-			bunt.Fprintf(&buf, "Lime{%s} DimGray{%s}\n",
-				commandIndicator,
-				strings.Join(args, " "),
-			)
+			if err := scaffold.AddCommand(args...); err != nil {
+				return err
+			}
 		}
 
 		// Run the provided command in a pseudo terminal and capture

internal/img/output.go

@@ -27,6 +27,7 @@ import (
 	"image/png"
 	"io"
 	"math"
+	"os"
 	"strings"
 
 	"github.com/esimov/stackblur-go"
@@ -49,6 +50,15 @@ const (
 	defaultFontDPI  = 144
 )
 
+// commandIndicator is the string to be used to indicate the command in the screenshot
+var commandIndicator = func() string {
+	if val, ok := os.LookupEnv("TS_COMMAND_INDICATOR"); ok {
+		return val
+	}
+
+	return "➜"
+}()
+
 type Scaffold struct {
 	content bunt.String
 
@@ -138,6 +148,15 @@ func (s *Scaffold) GetFixedColumns() int {
 	return columns
 }
 
+func (s *Scaffold) AddCommand(args ...string) error {
+	return s.AddContent(strings.NewReader(
+		bunt.Sprintf("Lime{%s} DimGray{%s}\n",
+			commandIndicator,
+			strings.Join(args, " "),
+		),
+	))
+}
+
 func (s *Scaffold) AddContent(in io.Reader) error {
 	parsed, err := bunt.ParseStream(in)
 	if err != nil {

internal/img/output_test.go

@@ -75,6 +75,13 @@ var _ = Describe("Creating images", func() {
 			Expect(scaffold).To(LookLike(testdata("expected-wrapping.png")))
 		})
 
+		It("should show the command when configured", func() {
+			scaffold := NewImageCreator()
+			Expect(scaffold.AddCommand("echo", "foobar")).To(Succeed())
+			Expect(scaffold.AddContent(strings.NewReader("foobar"))).To(Succeed())
+			Expect(scaffold).To(LookLike(testdata("expected-show-cmd.png")))
+		})
+
 		It("should write a PNG stream based on provided input with ANSI sequences", func() {
 			var buf bytes.Buffer
 			_, _ = Fprintf(&buf, "Text with emphasis, like *bold*, _italic_, _*bold/italic*_ or ~underline~.\n\n")