Colorize config output

This commit adds optional colorization of the config output. In certain
situations this can make reading configuration easier and it also looks
pretty neat.

There is also an optional --no-color flag that can be passed. This will
disable set the chroma formatter to `noop` rather than terminal16m.
Currently, the data is still tokenized by chroma but not formatted so
it does not print with any ascii codes.

In this implementation it doesn't matter too much because the size of
the configuration will always been small so there are no major
tradeoffs.. an improved solution could be to skip passing through chroma
if the --no-color flag is passed!

cmd/config.go

@@ -10,7 +10,10 @@ import (
 	"github.com/spf13/cobra"
 )
 
-var output string
+var (
+	output  string
+	noColor bool
+)
 
 // configCmd is the entry point for printing the applications configuration in the terminal
 var configCmd = &cobra.Command{
@@ -20,9 +23,9 @@ var configCmd = &cobra.Command{
 	RunE: func(command *cobra.Command, args []string) error {
 		switch output {
 		case "json":
-			return configuration.Config.PrintJSON(os.Stdout)
+			return configuration.Config.PrintJSON(noColor, os.Stdout)
 		case "yaml":
-			return configuration.Config.PrintYAML(os.Stdout)
+			return configuration.Config.PrintYAML(noColor, os.Stdout)
 		default:
 			return errors.New("invalid output format. Valid values are 'json' and 'yaml'")
 		}
@@ -31,4 +34,5 @@ var configCmd = &cobra.Command{
 
 func init() {
 	configCmd.Flags().StringVarP(&output, "output", "o", "yaml", "The output format. Valid values are 'json' and 'yaml'. Defaults to 'yaml'.")
+	configCmd.Flags().BoolVarP(&noColor, "no-color", "n", false, "Disable color output")
 }

go.mod

@@ -4,6 +4,7 @@ go 1.18
 
 require (
 	github.com/Masterminds/semver/v3 v3.1.1
+	github.com/alecthomas/chroma v0.10.0
 	github.com/briandowns/spinner v1.18.1
 	github.com/charmbracelet/bubbles v0.10.3
 	github.com/charmbracelet/bubbletea v0.20.0
@@ -21,7 +22,6 @@ require (
 )
 
 require (
-	github.com/alecthomas/chroma v0.10.0 // indirect
 	github.com/aymerick/douceur v0.2.0 // indirect
 	github.com/cli/safeexec v1.0.0 // indirect
 	github.com/cli/shurcooL-graphql v0.0.1 // indirect

internal/pkg/configuration/configuration.go

@@ -13,6 +13,10 @@ import (
 	"os"
 	"path/filepath"
 
+	"github.com/alecthomas/chroma"
+	"github.com/alecthomas/chroma/formatters"
+	"github.com/alecthomas/chroma/lexers"
+	"github.com/alecthomas/chroma/styles"
 	"github.com/spf13/viper"
 	"gopkg.in/yaml.v2"
 )
@@ -28,28 +32,73 @@ type configuration struct {
 	CheckForUpdates         bool                `mapstructure:"check_for_updates" yaml:"check_for_updates" json:"checkForUpdates"`
 }
 
-func write(data []byte, writer io.Writer) error {
-	_, err := fmt.Fprint(writer, string(data))
-	return err
+type writeOptions struct {
+	data      string
+	lexerName string
+	noColor   bool
+	writer    io.Writer
 }
 
-func (c *configuration) PrintJSON(writer io.Writer) error {
+func prettyWrite(opts writeOptions) error {
+	lexer := lexers.Get(opts.lexerName)
+	if lexer == nil {
+		lexer = lexers.Fallback
+	}
+
+	lexer = chroma.Coalesce(lexer)
+
+	style := styles.Get("native")
+	if style == nil {
+		style = styles.Fallback
+	}
+
+	formatter := formatters.Get("terminal16m")
+
+	if opts.noColor {
+		formatter = formatters.Get("noop")
+	}
+
+	iterator, err := lexer.Tokenise(nil, opts.data)
+	if err != nil {
+		return err
+	}
+
+	return formatter.Format(opts.writer, style, iterator)
+}
+
+func (c *configuration) PrintJSON(noColor bool, writer io.Writer) error {
 	b, err := json.MarshalIndent(c, "", "  ")
 	b = append(b, '\n')
 	if err != nil {
 		return err
 	}
 
-	return write(b, writer)
+	opts := writeOptions{
+		data:      string(b),
+		lexerName: "json",
+		noColor:   noColor,
+		writer:    writer,
+	}
+
+	return prettyWrite(opts)
 }
 
-func (c *configuration) PrintYAML(writer io.Writer) error {
+func (c *configuration) PrintYAML(noColor bool, writer io.Writer) error {
 	b, err := yaml.Marshal(c)
+	y := []byte("---\n")
+	y = append(y, b...)
 	if err != nil {
 		return err
 	}
 
-	return write(b, writer)
+	opts := writeOptions{
+		data:      string(y),
+		lexerName: "json",
+		noColor:   noColor,
+		writer:    writer,
+	}
+
+	return prettyWrite(opts)
 }
 
 func InitConfig() error {
@@ -103,4 +152,6 @@ func setDefaults() {
 	viper.SetDefault("show_unreleased", true)
 
 	viper.SetDefault("check_for_updates", true)
+
+	viper.SetDefault("no_color", false)
 }

internal/pkg/configuration/configuration_test.go

@@ -36,7 +36,7 @@ func TestPrintJSON(t *testing.T) {
 	config := configuration.Config
 
 	var buf bytes.Buffer
-	err = config.PrintJSON(&buf)
+	err = config.PrintJSON(true, &buf)
 	assert.NoError(t, err)
 
 	cfg := `{
@@ -73,10 +73,11 @@ func TestPrintYAML(t *testing.T) {
 	config := configuration.Config
 
 	var buf bytes.Buffer
-	err = config.PrintYAML(&buf)
+	err = config.PrintYAML(true, &buf)
 	assert.NoError(t, err)
 
-	cfg := `file_name: CHANGELOG.md
+	cfg := `---
+file_name: CHANGELOG.md
 excluded_labels:
 - maintenance
 sections: