extra rules by ast: add or delete empty lines

Author: hidu

.gitignore

@@ -10,3 +10,4 @@
 
 # Output of the go coverage tool, specifically when used with LiteIDE
 *.out
+*.got

README.md

@@ -7,20 +7,7 @@
 * 支持将多行的 copyright 注释修改为单行格式(默认不调整)
 * 简化代码
 * struct 赋值表达式，自动补齐 key
-
-
-<details><summary><i>Example</i></summary>
-
-```
-type User struct {
-	Name string
-	Age int
-}
-- u2 := User{"hello", 12}
-
-+ u2 := User{Name: "hello", Age: 12}
-```
-</details>
+* 补充空行、移除多余的空行
 
 对于 import 部分：
 > 1.可使用`-mi`参数来控制是否将多段import合并为一段（默认否）。  
@@ -32,6 +19,79 @@ type User struct {
 会忽略当前目录以及子目录下的 `testdata` 和 `vendor` 目录。  
 若需要可进入其目录里执行该命令。  
 
+
+<details><summary><i>Example 1：补齐 struct key</i></summary>
+
+```
+- u2 := User{"hello", 12}
++ u2 := User{Name: "hello", Age: 12}
+```
+</details>
+
+<details><summary><i>Example 2：注释格式化</i></summary>
+
+```
+- //User 注释内容
+- type User struct{
+
++ // User 注释内容
++ type User struct{
+```
+</details>
+
+<details><summary><i>Example 3：简化代码</i></summary>
+
+```
+- s[a:len(s)]
++ s[a:]
+
+- for x, _ = range v {...}
++ for x = range v {...}
+
+- for _ = range v {...}
++ for range v {...}
+```
+</details>
+
+<details><summary><i>Example 4：移除多余的空行</i></summary>
+
+1. 移除 struct 内部前后多余的空行：
+```
+- type userfn91 struct{
+-    
+-  name string
+- 
+- }
+
++ type userfn91 struct{
++  name string
++ }
+```
+
+2. 移除 func 内部前后多余的空行：
+```
+- fn1() {
+-	
+-	println("hello")
+-	
+- }
+
++ fn1() {
++	println("hello")
++	
++ }
+```
+
+3. 空 func 变为一行：
+```
+- fn1() {
+- }
+
++ fn1() {}
+```
+
+</details>
+
 ## 2.安装/更新
 ```bash
 export GO111MODULE=on
@@ -53,6 +113,7 @@ usage: go_fmt [flags] [path ...]
   -d	display diffs instead of rewriting files
   -df string
     	display diffs format, support: text, json (default "text")
+  -e	enable extra rules (default true)
   -ig string
     	import group sort rule,
     	stc: Go Standard pkgs, Third Party pkgs, Current ModuleByFile pkg
@@ -68,6 +129,8 @@ usage: go_fmt [flags] [path ...]
     	rewrite with build in rules:
     	a[b:len(a)] -> a[b:]
     	interface{} -> any
+    	a == ""     -> len(a) == 0
+    	a != ""     -> len(a) != 0
   -s	simplify code (default true)
   -slcr
     	multiline copyright to single-line

internal/common/debug.go

@@ -0,0 +1,24 @@
+// Copyright(C) 2022 github.com/fsgo  All Rights Reserved.
+// Author: hidu <[email protected]>
+// Date: 2022/10/6
+
+package common
+
+import (
+	"fmt"
+	"log"
+	"os"
+)
+
+// Debug 程序内部调试
+var Debug = os.Getenv("go_fmt_debug") == "1"
+
+var debugLogger = log.New(os.Stderr, "[Debug] ", log.Lshortfile)
+
+// DebugPrintln 打印调试日志
+func DebugPrintln(depth int, v ...any) {
+	if !Debug {
+		return
+	}
+	_ = debugLogger.Output(2+depth, fmt.Sprintln(v...))
+}

internal/common/options.go

@@ -83,6 +83,9 @@ type Options struct {
 
 	// 是否使用内置的 rewrite 规则简化代码，可选，默认 false
 	RewriteWithBuildIn bool
+
+	// Extra 更多额外的、高级的格式化规则
+	Extra bool
 }
 
 // ImportGroupType import 分组类型
@@ -138,6 +141,7 @@ func NewDefaultOptions() *Options {
 		Write:        true,
 		MergeImports: true,
 		Simplify:     true,
+		Extra:        false,
 	}
 }
 
@@ -175,8 +179,7 @@ func (opt *Options) AllGoFiles() ([]string, error) {
 			}
 			if info.IsDir() {
 				tmpList, err = allGoFiles(name)
-			} else {
-				// 若属实传入 文件名 可以不用检查是否是.go文件
+			} else { // 若属实传入 文件名 可以不用检查是否是.go文件
 				// 在一些特殊场景可能会有用
 				if len(opt.Files) == 1 || isGoFileName(name) {
 					tmpList = []string{name}
@@ -206,6 +209,7 @@ func (opt *Options) BindFlags() {
 	commandLine.BoolVar(&opt.Simplify, "s", true, "simplify code")
 	commandLine.StringVar(&opt.LocalModule, "local", "auto", "put imports beginning with this string as 3rd-party packages")
 	commandLine.BoolVar(&opt.Trace, "trace", false, "show trace infos")
+	commandLine.BoolVar(&opt.Extra, "e", true, "enable extra rules")
 	commandLine.BoolVar(&opt.MergeImports, "mi", false, "merge imports into one")
 	commandLine.BoolVar(&opt.SingleLineCopyright, "slcr", false, "multiline copyright to single-line")
 	commandLine.StringVar(&opt.ImportGroupRule, "ig", defaultImportGroupRule, `import group sort rule,

internal/common/parser.go

@@ -8,7 +8,6 @@ import (
 	"go/ast"
 	"go/parser"
 	"go/token"
-	"path/filepath"
 )
 
 // ParseOneFile 解析为 astFile
@@ -18,25 +17,3 @@ func ParseOneFile(fileName string, src []byte) (*token.FileSet, *ast.File, error
 	file, err := parser.ParseFile(fileSet, fileName, src, parserMode)
 	return fileSet, file, err
 }
-
-// ParseFile 解析文件，优先尝试使用 ParseDir
-func ParseFile(fileName string, src []byte) (*token.FileSet, *ast.File, error) {
-	fileSet := token.NewFileSet()
-	var file *ast.File
-	parserMode := parser.Mode(0) | parser.ParseComments
-	pkgs, err := parser.ParseDir(fileSet, filepath.Dir(fileName), nil, parserMode)
-	if err == nil {
-		for _, pkg := range pkgs {
-			for name, f := range pkg.Files {
-				if name == fileName {
-					file = f
-				}
-			}
-		}
-	}
-	if file == nil {
-		fileSet = token.NewFileSet()
-		file, err = parser.ParseFile(fileSet, fileName, src, parserMode)
-	}
-	return fileSet, file, err
-}

internal/common/request.go

@@ -5,28 +5,173 @@
 package common
 
 import (
+	"fmt"
 	"go/ast"
 	"go/token"
+	"os"
+	"reflect"
+	"sort"
 )
 
 // Request 一次格式化的请求
 type Request struct {
-	FileName string
-	FSet     *token.FileSet
-	AstFile  *ast.File
-	Opt      Options
+	FileName  string
+	FSet      *token.FileSet
+	AstFile   *ast.File
+	Opt       Options
+	tokenLine *TokenLine
+}
+
+// TokenLine 获取 TokenLine
+func (req *Request) TokenLine() *TokenLine {
+	if req.tokenLine == nil {
+		req.tokenLine = &TokenLine{
+			file: req.FSet.File(req.AstFile.Pos()),
+		}
+	}
+	return req.tokenLine
 }
 
 // FormatFile 将 AstFile 格式化、得到源码
 func (req *Request) FormatFile() ([]byte, error) {
 	return req.Opt.Source(req.FSet, req.AstFile)
 }
 
+// Save 保存文件
+func (req *Request) Save(name string) error {
+	code, err := req.FormatFile()
+	if err != nil {
+		return err
+	}
+	return os.WriteFile(name, code, 0644)
+}
+
 // ReParse 重新解析
-func (req *Request) ReParse() (*token.FileSet, *ast.File, error) {
+func (req *Request) ReParse() error {
+	fs, f, err := req.reParse()
+	if err == nil {
+		req.FSet = fs
+		req.AstFile = f
+	}
+	return err
+}
+
+// MustReParse 重新解析，若失败会 panic
+func (req *Request) MustReParse() {
+	if err := req.ReParse(); err != nil {
+		panic(fmt.Errorf("reParse %q failed: %w", req.FileName, err))
+	}
+}
+
+func (req *Request) reParse() (*token.FileSet, *ast.File, error) {
+	req.TokenLine().Execute()
 	code, err := req.FormatFile()
 	if err != nil {
 		return nil, nil, err
 	}
+	req.tokenLine = nil
 	return ParseOneFile(req.FileName, code)
 }
+
+// Clone reParser it and return a new Request
+func (req *Request) Clone() *Request {
+	c := &Request{
+		FileName: req.FileName,
+		Opt:      req.Opt,
+	}
+	fs, f, err := req.reParse()
+	if err != nil {
+		panic(fmt.Sprintf("reParser %q failed: %v", req.FileName, err))
+	}
+	c.FSet = fs
+	c.AstFile = f
+	return c
+}
+
+// TokenLine 记录对文件的换行的处理
+type TokenLine struct {
+	addPos     []int
+	deleteLine []int
+	file       *token.File
+}
+
+// AddLine 在指定位置添加新行
+func (tf *TokenLine) AddLine(depth int, at token.Pos) {
+	if Debug {
+		DebugPrintln(depth+1, "AddLine", tf.file.Position(at), "atPos=", at)
+	}
+	tf.addPos = append(tf.addPos, tf.file.Offset(at))
+}
+
+// DeleteLine 删除指定位置的新行
+func (tf *TokenLine) DeleteLine(depth int, line int) {
+	if line < 1 {
+		panic(fmt.Sprintf("invalid line number %d (should be >= 1)", line))
+	}
+	max := tf.file.LineCount()
+	if line > max {
+		panic(fmt.Sprintf("invalid line number %d (should be < %d)", line, max))
+	}
+	if Debug {
+		DebugPrintln(depth+1, "DeleteLine=", line, "lineStart=", tf.file.LineStart(line))
+	}
+	tf.deleteLine = append(tf.deleteLine, line)
+}
+
+// Execute 将 Add、 Delete 的结果生效
+func (tf *TokenLine) Execute() {
+	if len(tf.addPos) == 0 && len(tf.deleteLine) == 0 {
+		return
+	}
+	defer func() {
+		tf.addPos = nil
+		tf.deleteLine = nil
+	}()
+	lines := tokenFileLines(tf.file)
+	lines = intSliceDelete(lines, tf.deleteLine...)
+
+	lm := make(map[int]struct{}, len(lines))
+	for _, v := range lines {
+		lm[v] = struct{}{}
+	}
+	for _, offset := range tf.addPos {
+		lm[offset] = struct{}{}
+	}
+
+	result := make([]int, 0, len(lm))
+	for k := range lm {
+		if k >= tf.file.Size() {
+			continue
+		}
+		result = append(result, k)
+	}
+	sort.Ints(result)
+	if !tf.file.SetLines(result) {
+		panic(fmt.Sprintf("SetLines failed, size=%d, lines=%v", tf.file.Size(), result))
+	}
+}
+
+func tokenFileLines(f *token.File) []int {
+	field := reflect.ValueOf(f).Elem().FieldByName("lines")
+	total := field.Len()
+	lines := make([]int, 0, total)
+	for i := 0; i < total; i++ {
+		cur := int(field.Index(i).Int())
+		lines = append(lines, cur)
+	}
+	return lines
+}
+
+func intSliceDelete(lines []int, delete ...int) []int {
+	dm := make(map[int]bool, len(delete))
+	for _, v := range delete {
+		dm[v] = true
+	}
+	result := make([]int, 0, len(lines))
+	for line, v := range lines {
+		if !dm[line] {
+			result = append(result, v)
+		}
+	}
+	return result
+}