Add --compact option for dump and sync and make default pritty print

cmd/goast/cli.go

@@ -109,18 +109,29 @@ func run(args []string) error {
 }
 
 func cmdDump() *cli.Command {
-	var opt inspectOptions
+	var (
+		opt     inspectOptions
+		compact bool
+	)
 
 	return &cli.Command{
 		Name:    "dump",
 		Usage:   "output go codes as AST",
 		Aliases: []string{"d"},
-		Flags:   opt.Flags(),
+		Flags: append(opt.Flags(), []cli.Flag{
+			&cli.BoolFlag{
+				Name:        "compact",
+				Aliases:     []string{"c"},
+				Usage:       "Compact instead of pretty-printed output",
+				Destination: &compact,
+			},
+		}...),
 		Action: func(c *cli.Context) error {
 			codes := c.Args().Slice()
 
 			g := goast.New(
 				goast.WithInspectOptions(opt.Options()...),
+				goast.WithCompact(compact),
 			)
 			if err := walkCode(codes, func(filePath string, r io.Reader) error {
 				return g.Dump(filePath, r, os.Stdout)
@@ -134,13 +145,22 @@ func cmdDump() *cli.Command {
 }
 
 func cmdSync() *cli.Command {
-
+	var compact bool
 	return &cli.Command{
 		Name:    "sync",
 		Usage:   "sync dump of go codes to files",
 		Aliases: []string{"s"},
+		Flags: []cli.Flag{&cli.BoolFlag{
+			Name:        "compact",
+			Aliases:     []string{"c"},
+			Usage:       "Compact instead of pretty-printed output",
+			Destination: &compact,
+		},
+		},
 		Action: func(c *cli.Context) error {
-			g := goast.New()
+			g := goast.New(
+				goast.WithCompact(compact),
+			)
 
 			for _, src := range c.Args().Slice() {
 				if err := g.Sync(src); err != nil {

dump.go

@@ -2,7 +2,6 @@ package goast
 
 import (
 	"encoding/json"
-	"fmt"
 	"go/parser"
 	"go/token"
 	"io"
@@ -11,14 +10,16 @@ import (
 )
 
 func (x *Goast) Dump(filePath string, r io.Reader, w io.Writer) error {
+	encoder := json.NewEncoder(w)
+	if !x.dumpCompact {
+		encoder.SetIndent("", "  ")
+	}
+
 	dump := func(data *Node) error {
 		if x.dumpHook == nil {
-			raw, err := json.Marshal(data)
-			if err != nil {
-				return goerr.Wrap(err)
+			if err := encoder.Encode(data); err != nil {
+				return goerr.Wrap(err, "failed to encode dump data")
 			}
-
-			fmt.Fprintln(w, string(raw))
 			return nil
 		} else {
 			return x.dumpHook(data, w)

goast.go

@@ -16,7 +16,8 @@ type Goast struct {
 	mkdir  func(path string, perm fs.FileMode) error
 	walk   func(src string, cb func(fpath string, r io.Reader) error) error
 
-	dumpHook DumpHook
+	dumpCompact bool
+	dumpHook    DumpHook
 }
 
 type Option func(g *Goast)
@@ -54,3 +55,9 @@ func WithDumpHook(hook DumpHook) Option {
 }
 
 type DumpHook func(node *Node, w io.Writer) error
+
+func WithCompact(enable bool) Option {
+	return func(g *Goast) {
+		g.dumpCompact = enable
+	}
+}

sync.go

@@ -32,7 +32,11 @@ func (x *Goast) Sync(src string) error {
 			}
 		}()
 
-		if err := json.NewEncoder(fd).Encode(data); err != nil {
+		encoder := json.NewEncoder(fd)
+		if !x.dumpCompact {
+			encoder.SetIndent("", "  ")
+		}
+		if err := encoder.Encode(data); err != nil {
 			return goerr.Wrap(err, "failed to encode goast.Node")
 		}