feat: switch to use dst

go.mod

@@ -3,6 +3,7 @@ module github.com/haunt98/gofimports
 go 1.19
 
 require (
+	github.com/dave/dst v0.27.2
 	github.com/make-go-great/color-go v0.4.1
 	github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e
 	github.com/urfave/cli/v2 v2.23.7

go.sum

@@ -1,5 +1,8 @@
 github.com/cpuguy83/go-md2man/v2 v2.0.2 h1:p1EgwI/C7NhT0JmVkwCD2ZBK8j4aeHQX2pMHHBfMQ6w=
 github.com/cpuguy83/go-md2man/v2 v2.0.2/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
+github.com/dave/dst v0.27.2 h1:4Y5VFTkhGLC1oddtNwuxxe36pnyLxMFXT51FOzH8Ekc=
+github.com/dave/dst v0.27.2/go.mod h1:jHh6EOibnHgcUW3WjKHisiooEkYwqpHLBSX1iOBhEyc=
+github.com/dave/jennifer v1.5.0 h1:HmgPN93bVDpkQyYbqhCHj5QlgvUkvEOzMyEvKLgCRrg=
 github.com/fatih/color v1.13.0 h1:8LOYc1KYPPmyKMuN8QV2DNRWNbLo6LZ0iLs8+mlH53w=
 github.com/fatih/color v1.13.0/go.mod h1:kLAiJbzzSOZDVNGyDpeOxJ47H46qBXwg5ILebYFFOfk=
 github.com/make-go-great/color-go v0.4.1 h1:4HIat5r1oQneu5BSDUjHKN/9x4Ay2qEEkswdOgk/VRY=
@@ -13,6 +16,7 @@ github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e h1:aoZm08cpOy4WuID//EZDgc
 github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e/go.mod h1:pJLUxLENpZxwdsKMEsNbx1VGcRFpLqf3715MtcvvzbA=
 github.com/russross/blackfriday/v2 v2.1.0 h1:JIOH55/0cWyOuilr9/qlrm0BSXldqnqwMsf35Ld67mk=
 github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
+github.com/sergi/go-diff v1.2.0 h1:XU+rvMAioB0UC3q1MFrIQy4Vo5/4VsRDQQXHsEya6xQ=
 github.com/urfave/cli/v2 v2.23.7 h1:YHDQ46s3VghFHFf1DdF+Sh7H4RqhcM+t0TmZRJx4oJY=
 github.com/urfave/cli/v2 v2.23.7/go.mod h1:GHupkWPMM0M/sj1a2b4wUrWBPzazNrIjouW6fmdJLxc=
 github.com/xrash/smetrics v0.0.0-20201216005158-039620a65673 h1:bAn7/zixMGCfxrRTfdpNzjtPYqr8smhKouy9mxVdGPU=

internal/imports/formatter.go

@@ -4,9 +4,7 @@ import (
 	"bytes"
 	"errors"
 	"fmt"
-	"go/ast"
 	"go/parser"
-	"go/printer"
 	"go/token"
 	"io/fs"
 	"os"
@@ -14,6 +12,8 @@ import (
 	"strings"
 	"sync"
 
+	"github.com/dave/dst"
+	"github.com/dave/dst/decorator"
 	"github.com/pkg/diff"
 	"golang.org/x/mod/modfile"
 	"golang.org/x/tools/go/packages"
@@ -31,6 +31,7 @@ var (
 	ErrEmptyPaths       = errors.New("empty paths")
 	ErrNotGoFile        = errors.New("not go file")
 	ErrGoGeneratedFile  = errors.New("go generated file")
+	ErrAlreadyFormatted = errors.New("already formatted")
 	ErrGoModNotExist    = errors.New("go mod not exist")
 	ErrGoModEmptyModule = errors.New("go mod empty module")
 )
@@ -99,6 +100,10 @@ func (ft *Formatter) Format(paths ...string) error {
 			}
 		default:
 			if err := ft.formatFile(path); err != nil {
+				if ft.isIgnoreError(err) {
+					continue
+				}
+
 				return err
 			}
 		}
@@ -123,8 +128,7 @@ func (ft *Formatter) formatDir(path string) error {
 		}
 
 		if err := ft.formatFile(path); err != nil {
-			if errors.Is(err, ErrNotGoFile) ||
+			if ft.isIgnoreError(err) {
-				errors.Is(err, ErrGoGeneratedFile) {
 				return nil
 			}
 
@@ -163,13 +167,17 @@ func (ft *Formatter) formatFile(path string) error {
 	if err != nil {
 		return err
 	}
-	ft.log("formatFile: moduleName: %+v\n", moduleName)
+	ft.log("formatFile: moduleName: [%s]\n", moduleName)
 
 	formattedBytes, err := ft.formatImports(path, pathBytes, moduleName)
 	if err != nil {
 		return err
 	}
 
+	if bytes.Compare(pathBytes, formattedBytes) == 0 {
+		return ErrAlreadyFormatted
+	}
+
 	if ft.isList {
 		fmt.Println("Formatted: ", path)
 	}
@@ -226,103 +234,49 @@ func (ft *Formatter) formatImports(
 		return nil, ErrGoGeneratedFile
 	}
 
-	// Extract imports
+	dstFile, err := decorator.Parse(pathBytes)
-	importSpecs := make([]ast.Spec, 0, len(astFile.Imports))
+	if err != nil {
-	for _, importSpec := range astFile.Imports {
+		return nil, fmt.Errorf("decorator: failed to parse file [%s]: %w", path, err)
-		importSpecs = append(importSpecs, importSpec)
 	}
-	ft.mustLogImportSpecs("formatImports: importSpecs", importSpecs)
+	ft.logDSTImportSpecs("formatImports: dstImportSpecs", dstFile.Imports)
 
-	groupedImportSpecs, err := ft.groupImportSpecs(
+	groupedDSTImportSpecs, err := ft.groupDSTImportSpecs(
-		importSpecs,
+		dstFile.Imports,
 		moduleName,
 	)
 	if err != nil {
 		return nil, err
 	}
 
-	formattedImportSpecs, err := ft.formatImportSpecs(
+	formattedDSTImportSpecs, err := ft.formatDSTImportSpecs(groupedDSTImportSpecs)
-		importSpecs,
-		groupedImportSpecs,
-	)
 	if err != nil {
 		return nil, err
 	}
-	ft.mustLogImportSpecs("formatImports: formattedImportSpecs: ", formattedImportSpecs)
+	ft.logDSTImportSpecs("formatImports: formattedDSTImportSpecs: ", formattedDSTImportSpecs)
 
-	// Combine multi import decl into one
+	dstFile.Imports = formattedDSTImportSpecs
-	isExistFirstImportDecl := false
-	decls := make([]ast.Decl, 0, len(astFile.Decls))
 
-	for _, decl := range astFile.Decls {
+	var buf bytes.Buffer
-		genDecl, ok := decl.(*ast.GenDecl)
+	if err := decorator.Fprint(&buf, dstFile); err != nil {
-		if !ok {
+		return nil, fmt.Errorf("decorator: failed to fprint [%s]: %w", path, err)
-			decls = append(decls, decl)
-			continue
-		}
-
-		if genDecl.Tok != token.IMPORT {
-			decls = append(decls, decl)
-			continue
-		}
-
-		// Ignore second import decl and more
-		if isExistFirstImportDecl {
-			continue
-		}
-
-		// Ignore empty import
-		if len(genDecl.Specs) == 0 {
-			continue
-		}
-
-		// First import decl take all
-		isExistFirstImportDecl = true
-		genDecl.Specs = formattedImportSpecs
-		decls = append(decls, genDecl)
 	}
 
-	// Update ast decls
+	return buf.Bytes(), nil
-	astFile.Decls = decls
-
-	// Print formatted bytes from formatted ast
-	var formattedBytes []byte
-	formattedBuffer := bytes.NewBuffer(formattedBytes)
-
-	// Copy from goimports
-	printerMode := printer.UseSpaces
-	printerMode |= printer.TabIndent
-	printerCfg := &printer.Config{
-		Mode:     printerMode,
-		Tabwidth: 8,
-	}
-	if err := printerCfg.Fprint(formattedBuffer, fset, astFile); err != nil {
-		return nil, fmt.Errorf("printer: failed to fprint: %w", err)
-	}
-
-	return formattedBuffer.Bytes(), nil
 }
 
-// Copy from goimports-reviser
+func (ft *Formatter) groupDSTImportSpecs(
-// Group imports to std, third-party, company if exist, local
+	importSpecs []*dst.ImportSpec,
-func (ft *Formatter) groupImportSpecs(
-	importSpecs []ast.Spec,
 	moduleName string,
-) (map[string][]*ast.ImportSpec, error) {
+) (map[string][]*dst.ImportSpec, error) {
-	result := make(map[string][]*ast.ImportSpec)
+	result := make(map[string][]*dst.ImportSpec)
-	result[stdImport] = make([]*ast.ImportSpec, 0, 8)
+	result[stdImport] = make([]*dst.ImportSpec, 0, 8)
-	result[thirdPartyImport] = make([]*ast.ImportSpec, 0, 8)
+	result[thirdPartyImport] = make([]*dst.ImportSpec, 0, 8)
 	if ft.companyPrefix != "" {
-		result[companyImport] = make([]*ast.ImportSpec, 0, 8)
+		result[companyImport] = make([]*dst.ImportSpec, 0, 8)
 	}
-	result[localImport] = make([]*ast.ImportSpec, 0, 8)
+	result[localImport] = make([]*dst.ImportSpec, 0, 8)
 
 	for _, importSpec := range importSpecs {
-		importSpec, ok := importSpec.(*ast.ImportSpec)
-		if !ok {
-			continue
-		}
-
 		// "github.com/abc/xyz" -> github.com/abc/xyz
 		importPath := strings.Trim(importSpec.Path.Value, `"`)
 
@@ -345,61 +299,43 @@ func (ft *Formatter) groupImportSpecs(
 		result[thirdPartyImport] = append(result[thirdPartyImport], importSpec)
 	}
 
-	ft.logImportSpecs("stdImport", result[stdImport])
+	ft.logDSTImportSpecs("groupDSTImportSpecs: stdImport", result[stdImport])
-	ft.logImportSpecs("thirdPartyImport", result[thirdPartyImport])
+	ft.logDSTImportSpecs("groupDSTImportSpecs: thirdPartyImport", result[thirdPartyImport])
 	if ft.companyPrefix != "" {
-		ft.logImportSpecs("companyImport", result[companyImport])
+		ft.logDSTImportSpecs("groupDSTImportSpecs: companyImport", result[companyImport])
 	}
-	ft.logImportSpecs("localImport", result[localImport])
+	ft.logDSTImportSpecs("groupDSTImportSpecs: localImport", result[localImport])
 
 	return result, nil
 }
 
-// Copy from goimports-reviser
+func (ft *Formatter) formatDSTImportSpecs(groupedImportSpecs map[string][]*dst.ImportSpec,
-// Insert empty import (empty path) between groups
+) ([]*dst.ImportSpec, error) {
-func (ft *Formatter) formatImportSpecs(
+	result := make([]*dst.ImportSpec, 0, 32)
-	importSpecs []ast.Spec,
-	groupedImportSpecs map[string][]*ast.ImportSpec,
-) ([]ast.Spec, error) {
-	result := make([]ast.Spec, 0, len(importSpecs))
 
 	appendToResultFn := func(groupImportType string) {
-		if specs, ok := groupedImportSpecs[groupImportType]; ok && len(specs) != 0 {
+		importSpecs, ok := groupedImportSpecs[groupImportType]
-			if len(result) != 0 {
+		if !ok || len(importSpecs) == 0 {
-				result = append(result, &ast.ImportSpec{
+			return
-					Path: &ast.BasicLit{
-						Value: "",
-						Kind:  token.STRING,
-					},
-				})
-			}
-
-			for _, spec := range specs {
-				newSpec := &ast.ImportSpec{
-					Path: &ast.BasicLit{
-						Value: spec.Path.Value,
-						Kind:  token.STRING,
-					},
-				}
-
-				if spec.Name != nil {
-					newSpec.Name = &ast.Ident{
-						Name: spec.Name.Name,
-					}
-				}
-
-				result = append(result, newSpec)
-			}
 		}
+
+		for _, importSpec := range importSpecs {
+			importSpec.Decs.Before = dst.NewLine
+			importSpec.Decs.After = dst.NewLine
+		}
+
+		importSpecs[len(importSpecs)-1].Decs.After = dst.EmptyLine
+
+		result = append(result, importSpecs...)
 	}
 
 	appendToResultFn(stdImport)
 	appendToResultFn(thirdPartyImport)
-	if ft.companyPrefix != "" {
+	appendToResultFn(companyImport)
-		appendToResultFn(companyImport)
-	}
 	appendToResultFn(localImport)
 
+	result[len(result)-1].Decs.After = dst.NewLine
+
 	return result, nil
 }
 
@@ -462,3 +398,9 @@ func (ft *Formatter) moduleName(path string) (string, error) {
 
 	return result, nil
 }
+
+func (ft *Formatter) isIgnoreError(err error) bool {
+	return errors.Is(err, ErrNotGoFile) ||
+		errors.Is(err, ErrGoGeneratedFile) ||
+		errors.Is(err, ErrAlreadyFormatted)
+}

internal/imports/formatter_log.go

@@ -1,8 +1,9 @@
 package imports
 
 import (
-	"go/ast"
 	"log"
+
+	"github.com/dave/dst"
 )
 
 // Wrap log.Printf with verbose flag
@@ -12,23 +13,10 @@ func (ft *Formatter) log(format string, v ...any) {
 	}
 }
 
-func (ft *Formatter) logImportSpecs(logPrefix string, importSpecs []*ast.ImportSpec) {
+func (ft *Formatter) logDSTImportSpecs(logPrefix string, importSpecs []*dst.ImportSpec) {
 	if ft.isVerbose {
 		for _, importSpec := range importSpecs {
-			log.Printf("%s: importSpec: %+v %+v\n", logPrefix, importSpec.Name.String(), importSpec.Path.Value)
+			log.Printf("%s: [%s] [%s] before %v after %v\n", logPrefix, importSpec.Name, importSpec.Path.Value, importSpec.Decs.Before, importSpec.Decs.After)
-		}
-	}
-}
-
-func (ft *Formatter) mustLogImportSpecs(logPrefix string, importSpecs []ast.Spec) {
-	if ft.isVerbose {
-		for _, importSpec := range importSpecs {
-			importSpec, ok := importSpec.(*ast.ImportSpec)
-			if !ok {
-				continue
-			}
-
-			log.Printf("%s: importSpec: %+v %+v\n", logPrefix, importSpec.Name.String(), importSpec.Path.Value)
 		}
 	}
 }