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| -rw-r--r-- | .gitignore | 1 | ||||
| -rw-r--r-- | LICENSE.txt | 674 | ||||
| -rw-r--r-- | README.md | 212 | ||||
| -rw-r--r-- | formatter.go | 315 | ||||
| -rw-r--r-- | formatter_bench_test.go | 49 | ||||
| -rw-r--r-- | formatter_test.go | 424 | ||||
| -rw-r--r-- | go.mod | 3 | ||||
| -rw-r--r-- | main.go | 235 |
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diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..034047c --- /dev/null +++ b/.gitignore @@ -0,0 +1 @@ +iku diff --git a/LICENSE.txt b/LICENSE.txt new file mode 100644 index 0000000..f288702 --- /dev/null +++ b/LICENSE.txt @@ -0,0 +1,674 @@ + GNU GENERAL PUBLIC LICENSE + Version 3, 29 June 2007 + + Copyright (C) 2007 Free Software Foundation, Inc. <https://fsf.org/> + Everyone is permitted to copy and distribute verbatim copies + of this license document, but changing it is not allowed. + + Preamble + + The GNU General Public License is a free, copyleft license for +software and other kinds of works. + + The licenses for most software and other practical works are designed +to take away your freedom to share and change the works. By contrast, +the GNU General Public License is intended to guarantee your freedom to +share and change all versions of a program--to make sure it remains free +software for all its users. We, the Free Software Foundation, use the +GNU General Public License for most of our software; it applies also to +any other work released this way by its authors. You can apply it to +your programs, too. + + When we speak of free software, we are referring to freedom, not +price. Our General Public Licenses are designed to make sure that you +have the freedom to distribute copies of free software (and charge for +them if you wish), that you receive source code or can get it if you +want it, that you can change the software or use pieces of it in new +free programs, and that you know you can do these things. + + To protect your rights, we need to prevent others from denying you +these rights or asking you to surrender the rights. Therefore, you have +certain responsibilities if you distribute copies of the software, or if +you modify it: responsibilities to respect the freedom of others. + + For example, if you distribute copies of such a program, whether +gratis or for a fee, you must pass on to the recipients the same +freedoms that you received. You must make sure that they, too, receive +or can get the source code. And you must show them these terms so they +know their rights. + + Developers that use the GNU GPL protect your rights with two steps: +(1) assert copyright on the software, and (2) offer you this License +giving you legal permission to copy, distribute and/or modify it. + + For the developers' and authors' protection, the GPL clearly explains +that there is no warranty for this free software. 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If the +Program specifies that a certain numbered version of the GNU General +Public License "or any later version" applies to it, you have the +option of following the terms and conditions either of that numbered +version or of any later version published by the Free Software +Foundation. If the Program does not specify a version number of the +GNU General Public License, you may choose any version ever published +by the Free Software Foundation. + + If the Program specifies that a proxy can decide which future +versions of the GNU General Public License can be used, that proxy's +public statement of acceptance of a version permanently authorizes you +to choose that version for the Program. + + Later license versions may give you additional or different +permissions. However, no additional obligations are imposed on any +author or copyright holder as a result of your choosing to follow a +later version. + + 15. Disclaimer of Warranty. + + THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY +APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT +HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY +OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, +THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR +PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM +IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF +ALL NECESSARY SERVICING, REPAIR OR CORRECTION. + + 16. Limitation of Liability. + + IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING +WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS +THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY +GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE +USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF +DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD +PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), +EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF +SUCH DAMAGES. + + 17. Interpretation of Sections 15 and 16. + + If the disclaimer of warranty and limitation of liability provided +above cannot be given local legal effect according to their terms, +reviewing courts shall apply local law that most closely approximates +an absolute waiver of all civil liability in connection with the +Program, unless a warranty or assumption of liability accompanies a +copy of the Program in return for a fee. + + END OF TERMS AND CONDITIONS + + How to Apply These Terms to Your New Programs + + If you develop a new program, and you want it to be of the greatest +possible use to the public, the best way to achieve this is to make it +free software which everyone can redistribute and change under these terms. + + To do so, attach the following notices to the program. It is safest +to attach them to the start of each source file to most effectively +state the exclusion of warranty; and each file should have at least +the "copyright" line and a pointer to where the full notice is found. + + <one line to give the program's name and a brief idea of what it does.> + Copyright (C) <year> <name of author> + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. + +Also add information on how to contact you by electronic and paper mail. + + If the program does terminal interaction, make it output a short +notice like this when it starts in an interactive mode: + + <program> Copyright (C) <year> <name of author> + This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'. + This is free software, and you are welcome to redistribute it + under certain conditions; type `show c' for details. + +The hypothetical commands `show w' and `show c' should show the appropriate +parts of the General Public License. Of course, your program's commands +might be different; for a GUI interface, you would use an "about box". + + You should also get your employer (if you work as a programmer) or school, +if any, to sign a "copyright disclaimer" for the program, if necessary. +For more information on this, and how to apply and follow the GNU GPL, see +<https://www.gnu.org/licenses/>. + + The GNU General Public License does not permit incorporating your program +into proprietary programs. If your program is a subroutine library, you +may consider it more useful to permit linking proprietary applications with +the library. If this is what you want to do, use the GNU Lesser General +Public License instead of this License. But first, please read +<https://www.gnu.org/licenses/why-not-lgpl.html>. diff --git a/README.md b/README.md new file mode 100644 index 0000000..53da068 --- /dev/null +++ b/README.md @@ -0,0 +1,212 @@ +# 🚀 Iku + +> Grammar-Aware Go Formatter + +Iku is a grammar-based Go formatter that enforces consistent blank-line placement by AST node type. + +## Philosophy + +Code structure should be visually apparent from its formatting. Iku groups statements by grammatical type and separates them with blank lines, making the code flow easier to read at a glance. + +## Rules + +1. **Same AST type means no blank line**: Consecutive statements of the same type stay together +2. **Different AST type means blank line**: Transitions between statement types get visual separation +3. **Scoped statements get blank lines**: `if`, `for`, `switch`, `select` always have blank lines before them +4. **Top-level declarations are separated**: Functions, types, and variables at the package level get blank lines between them + +## How It Works + +Iku runs `go fmt` first, then applies its grammar-based blank-line rules on top of it. Your code gets standard Go formatting plus structural separation. + +## Installation + +```bash +go install github.com/Fuwn/iku@latest +``` + +## Usage + +```bash +# Format stdin +echo 'package main...' | iku + +# Format and print to stdout +iku file.go + +# Format in-place +iku -w file.go + +# Format entire directory +iku -w ./... + +# List files that need formatting +iku -l . + +# Show diff +iku -d file.go +``` + +### Flags + +| Flag | Description | +|------|-------------| +| `-w` | Write result to file instead of stdout | +| `-l` | List files whose formatting differs | +| `-d` | Display diffs instead of rewriting | +| `--comments` | Comment attachment mode: `follow`, `precede`, `standalone` | +| `--version` | Print version | + +## Examples + +### Before + +```go +package main + +func main() { + x := 1 + y := 2 + var config = loadConfig() + defer cleanup() + defer closeDB() + if err != nil { + return err + } + if x > 0 { + process(x) + } + go worker() + return nil +} +``` + +### After + +```go +package main + +func main() { + x := 1 + y := 2 + + var config = loadConfig() + + defer cleanup() + defer closeDB() + + if err != nil { + return err + } + + if x > 0 { + process(x) + } + + go worker() + + return nil +} +``` + +Notice how: +- `x := 1` and `y := 2` (both `AssignStmt`) stay together +- `var config` (`DeclStmt`) gets separated from assignments +- `defer` statements stay grouped together +- Each `if` statement gets a blank line before it (scoped statement) +- `go worker()` (`GoStmt`) is separated from the `if` above +- `return` (`ReturnStmt`) is separated from the `go` statement + +### Top-Level Declarations + +```go +// Before +package main +type Config struct { + Name string +} +var defaultConfig = Config{} +func main() { + run() +} +func run() { + process() +} + +// After +package main + +type Config struct { + Name string +} + +var defaultConfig = Config{} + +func main() { + run() +} + +func run() { + process() +} +``` + +### Switch Statements + +```go +// Before +func process(x int) { + result := compute(x) + switch result { + case 1: + handleOne() + if needsExtra { + doExtra() + } + case 2: + handleTwo() + } + cleanup() +} + +// After +func process(x int) { + result := compute(x) + + switch result { + case 1: + handleOne() + + if needsExtra { + doExtra() + } + case 2: + handleTwo() + } + + cleanup() +} +``` + +## AST Node Types + +For reference, here are common Go statement types that Iku distinguishes: + +| Type | Examples | +|------|----------| +| `*ast.AssignStmt` | `x := 1`, `x = 2` | +| `*ast.DeclStmt` | `var x = 1` | +| `*ast.ExprStmt` | `fmt.Println()`, `doSomething()` | +| `*ast.ReturnStmt` | `return x` | +| `*ast.IfStmt` | `if x > 0 { }` | +| `*ast.ForStmt` | `for i := 0; i < n; i++ { }` | +| `*ast.RangeStmt` | `for k, v := range m { }` | +| `*ast.SwitchStmt` | `switch x { }` | +| `*ast.SelectStmt` | `select { }` | +| `*ast.DeferStmt` | `defer f()` | +| `*ast.GoStmt` | `go f()` | +| `*ast.SendStmt` | `ch <- x` | + +## License + +This project is licensed under the [GNU General Public License v3.0](./LICENSE.txt). diff --git a/formatter.go b/formatter.go new file mode 100644 index 0000000..8d249cb --- /dev/null +++ b/formatter.go @@ -0,0 +1,315 @@ +package main + +import ( + "go/ast" + "go/format" + "go/parser" + "go/token" + "reflect" + "regexp" + "strings" +) + +type CommentMode int + +const ( + CommentsFollow CommentMode = iota + CommentsPrecede + CommentsStandalone +) + +type Formatter struct { + CommentMode CommentMode +} + +type lineInfo struct { + statementType string + isTopLevel bool + isScoped bool + isStartLine bool +} + +func (f *Formatter) Format(source []byte) ([]byte, error) { + formatted, err := format.Source(source) + + if err != nil { + return nil, err + } + + fileSet := token.NewFileSet() + file, err := parser.ParseFile(fileSet, "", formatted, parser.ParseComments) + + if err != nil { + return nil, err + } + + lineInfoMap := f.buildLineInfo(fileSet, file) + + return f.rewrite(formatted, lineInfoMap), nil +} + +func (f *Formatter) buildLineInfo(fileSet *token.FileSet, file *ast.File) map[int]*lineInfo { + lineInfoMap := make(map[int]*lineInfo) + tokenFile := fileSet.File(file.Pos()) + + if tokenFile == nil { + return lineInfoMap + } + + for _, declaration := range file.Decls { + startLine := tokenFile.Line(declaration.Pos()) + endLine := tokenFile.Line(declaration.End()) + typeName := reflect.TypeOf(declaration).String() + lineInfoMap[startLine] = &lineInfo{statementType: typeName, isTopLevel: true, isStartLine: true} + lineInfoMap[endLine] = &lineInfo{statementType: typeName, isTopLevel: true, isStartLine: false} + } + + ast.Inspect(file, func(node ast.Node) bool { + if node == nil { + return true + } + + switch typedNode := node.(type) { + case *ast.BlockStmt: + f.processBlock(tokenFile, typedNode, lineInfoMap) + case *ast.CaseClause: + f.processStatementList(tokenFile, typedNode.Body, lineInfoMap) + case *ast.CommClause: + f.processStatementList(tokenFile, typedNode.Body, lineInfoMap) + } + + return true + }) + + return lineInfoMap +} + +func (f *Formatter) processBlock(tokenFile *token.File, block *ast.BlockStmt, lineInfoMap map[int]*lineInfo) { + if block == nil { + return + } + + f.processStatementList(tokenFile, block.List, lineInfoMap) +} + +func (f *Formatter) processStatementList(tokenFile *token.File, statements []ast.Stmt, lineInfoMap map[int]*lineInfo) { + for _, statement := range statements { + startLine := tokenFile.Line(statement.Pos()) + endLine := tokenFile.Line(statement.End()) + typeName := reflect.TypeOf(statement).String() + isScoped := false + + switch statement.(type) { + case *ast.IfStmt, *ast.ForStmt, *ast.RangeStmt, *ast.SwitchStmt, + *ast.TypeSwitchStmt, *ast.SelectStmt, *ast.BlockStmt: + + isScoped = true + } + + existingStart := lineInfoMap[startLine] + + if existingStart == nil || !existingStart.isStartLine { + lineInfoMap[startLine] = &lineInfo{statementType: typeName, isTopLevel: false, isScoped: isScoped, isStartLine: true} + } + + existingEnd := lineInfoMap[endLine] + + if existingEnd == nil || !existingEnd.isStartLine { + lineInfoMap[endLine] = &lineInfo{statementType: typeName, isTopLevel: false, isScoped: isScoped, isStartLine: false} + } + + switch typedStatement := statement.(type) { + case *ast.IfStmt: + f.processBlock(tokenFile, typedStatement.Body, lineInfoMap) + + if typedStatement.Else != nil { + if elseBlock, isBlockStatement := typedStatement.Else.(*ast.BlockStmt); isBlockStatement { + f.processBlock(tokenFile, elseBlock, lineInfoMap) + } else if elseIfStatement, isIfStatement := typedStatement.Else.(*ast.IfStmt); isIfStatement { + f.processIfStatement(tokenFile, elseIfStatement, lineInfoMap) + } + } + case *ast.ForStmt: + f.processBlock(tokenFile, typedStatement.Body, lineInfoMap) + case *ast.RangeStmt: + f.processBlock(tokenFile, typedStatement.Body, lineInfoMap) + case *ast.SwitchStmt: + f.processBlock(tokenFile, typedStatement.Body, lineInfoMap) + case *ast.TypeSwitchStmt: + f.processBlock(tokenFile, typedStatement.Body, lineInfoMap) + case *ast.SelectStmt: + f.processBlock(tokenFile, typedStatement.Body, lineInfoMap) + case *ast.BlockStmt: + f.processBlock(tokenFile, typedStatement, lineInfoMap) + } + } +} + +func (f *Formatter) processIfStatement(tokenFile *token.File, ifStatement *ast.IfStmt, lineInfoMap map[int]*lineInfo) { + startLine := tokenFile.Line(ifStatement.Pos()) + endLine := tokenFile.Line(ifStatement.End()) + existingStart := lineInfoMap[startLine] + + if existingStart == nil || !existingStart.isStartLine { + lineInfoMap[startLine] = &lineInfo{statementType: "*ast.IfStmt", isTopLevel: false, isScoped: true, isStartLine: true} + } + + existingEnd := lineInfoMap[endLine] + + if existingEnd == nil || !existingEnd.isStartLine { + lineInfoMap[endLine] = &lineInfo{statementType: "*ast.IfStmt", isTopLevel: false, isScoped: true, isStartLine: false} + } + + f.processBlock(tokenFile, ifStatement.Body, lineInfoMap) + + if ifStatement.Else != nil { + if elseBlock, isBlockStatement := ifStatement.Else.(*ast.BlockStmt); isBlockStatement { + f.processBlock(tokenFile, elseBlock, lineInfoMap) + } else if elseIfStatement, isIfStatement := ifStatement.Else.(*ast.IfStmt); isIfStatement { + f.processIfStatement(tokenFile, elseIfStatement, lineInfoMap) + } + } +} + +func (f *Formatter) rewrite(source []byte, lineInfoMap map[int]*lineInfo) []byte { + lines := strings.Split(string(source), "\n") + + var result []string + + closingBracePattern := regexp.MustCompile(`^\s*[\}\)]`) + openingBracePattern := regexp.MustCompile(`[\{\(]\s*$`) + caseLabelPattern := regexp.MustCompile(`^\s*(case\s+.*|default\s*):\s*$`) + commentOnlyPattern := regexp.MustCompile(`^\s*//`) + packageLinePattern := regexp.MustCompile(`^package\s+`) + previousWasOpenBrace := false + previousType := "" + previousWasComment := false + previousWasTopLevel := false + insideRawString := false + + for index, line := range lines { + backtickCount := strings.Count(line, "`") + wasInsideRawString := insideRawString + + if backtickCount%2 == 1 { + insideRawString = !insideRawString + } + + if wasInsideRawString { + result = append(result, line) + continue + } + + lineNumber := index + 1 + trimmed := strings.TrimSpace(line) + isBlank := trimmed == "" + isClosingBrace := closingBracePattern.MatchString(line) + isOpeningBrace := openingBracePattern.MatchString(line) + isCaseLabel := caseLabelPattern.MatchString(line) + isCommentOnlyLine := commentOnlyPattern.MatchString(line) + isPackageLine := packageLinePattern.MatchString(trimmed) + + if isBlank { + continue + } + + info := lineInfoMap[lineNumber] + currentType := "" + + if info != nil { + currentType = info.statementType + } + + if isPackageLine { + currentType = "package" + } + + needsBlank := false + currentIsTopLevel := info != nil && info.isTopLevel + currentIsScoped := info != nil && info.isScoped + + if len(result) > 0 && !previousWasOpenBrace && !isClosingBrace && !isCaseLabel { + if currentIsTopLevel && previousWasTopLevel { + if f.CommentMode == CommentsFollow && previousWasComment { + } else { + needsBlank = true + } + } else if currentIsScoped { + if f.CommentMode == CommentsFollow && previousWasComment { + } else { + needsBlank = true + } + } else if currentType != "" && previousType != "" && currentType != previousType { + if f.CommentMode == CommentsFollow && previousWasComment { + } else { + needsBlank = true + } + } + + if f.CommentMode == CommentsFollow && isCommentOnlyLine && !previousWasComment { + nextLineNumber := f.findNextNonCommentLine(lines, index+1) + + if nextLineNumber > 0 { + nextInfo := lineInfoMap[nextLineNumber] + + if nextInfo != nil { + nextIsTopLevel := nextInfo.isTopLevel + nextIsScoped := nextInfo.isScoped + + if nextIsTopLevel && previousWasTopLevel { + needsBlank = true + } else if nextIsScoped { + needsBlank = true + } else if nextInfo.statementType != "" && previousType != "" && nextInfo.statementType != previousType { + needsBlank = true + } + } + } + } + } + + if needsBlank { + result = append(result, "") + } + + result = append(result, line) + previousWasOpenBrace = isOpeningBrace || isCaseLabel + previousWasComment = isCommentOnlyLine + + if info != nil { + previousType = info.statementType + previousWasTopLevel = info.isTopLevel + } else if currentType != "" { + previousType = currentType + previousWasTopLevel = false + } + } + + output := strings.Join(result, "\n") + + if !strings.HasSuffix(output, "\n") { + output += "\n" + } + + return []byte(output) +} + +func (f *Formatter) findNextNonCommentLine(lines []string, startIndex int) int { + commentOnlyPattern := regexp.MustCompile(`^\s*//`) + + for index := startIndex; index < len(lines); index++ { + trimmed := strings.TrimSpace(lines[index]) + + if trimmed == "" { + continue + } + + if commentOnlyPattern.MatchString(lines[index]) { + continue + } + + return index + 1 + } + + return 0 +} diff --git a/formatter_bench_test.go b/formatter_bench_test.go new file mode 100644 index 0000000..53f607b --- /dev/null +++ b/formatter_bench_test.go @@ -0,0 +1,49 @@ +package main + +import ( + "strings" + "testing" +) + +func BenchmarkFormat_Small(b *testing.B) { + input := []byte(`package main +func main() { + x := 1 + y := 2 + if x > 0 { + z := 3 + } + a := 4 +} +`) + f := &Formatter{CommentMode: CommentsFollow} + + for b.Loop() { + _, _ = f.Format(input) + } +} + +func BenchmarkFormat_Large(b *testing.B) { + var sb strings.Builder + + sb.WriteString("package main\n\n") + + for i := range 100 { + sb.WriteString("func foo") + sb.WriteString(string(rune('A' + i%26))) + sb.WriteString("() {\n") + sb.WriteString("\tx := 1\n") + sb.WriteString("\tif x > 0 {\n") + sb.WriteString("\t\ty := 2\n") + sb.WriteString("\t}\n") + sb.WriteString("\tz := 3\n") + sb.WriteString("}\n\n") + } + + input := []byte(sb.String()) + f := &Formatter{CommentMode: CommentsFollow} + + for b.Loop() { + _, _ = f.Format(input) + } +} diff --git a/formatter_test.go b/formatter_test.go new file mode 100644 index 0000000..e88d9f5 --- /dev/null +++ b/formatter_test.go @@ -0,0 +1,424 @@ +package main + +import ( + "testing" +) + +func TestFormat_RemovesExtraBlankLines(t *testing.T) { + input := `package main + +func main() { + x := 1 + + + y := 2 +} +` + expected := `package main + +func main() { + x := 1 + y := 2 +} +` + f := &Formatter{CommentMode: CommentsFollow} + result, err := f.Format([]byte(input)) + + if err != nil { + t.Fatalf("Format error: %v", err) + } + + if string(result) != expected { + t.Errorf("got:\n%s\nwant:\n%s", result, expected) + } +} + +func TestFormat_AddsBlankLineAroundScopedStatements(t *testing.T) { + input := `package main + +func main() { + x := 1 + if x > 0 { + y := 2 + } + z := 3 +} +` + expected := `package main + +func main() { + x := 1 + + if x > 0 { + y := 2 + } + + z := 3 +} +` + f := &Formatter{CommentMode: CommentsFollow} + result, err := f.Format([]byte(input)) + + if err != nil { + t.Fatalf("Format error: %v", err) + } + + if string(result) != expected { + t.Errorf("got:\n%s\nwant:\n%s", result, expected) + } +} + +func TestFormat_NestedScopes(t *testing.T) { + input := `package main + +func main() { + if true { + x := 1 + if false { + y := 2 + } + z := 3 + } +} +` + expected := `package main + +func main() { + if true { + x := 1 + + if false { + y := 2 + } + + z := 3 + } +} +` + f := &Formatter{CommentMode: CommentsFollow} + result, err := f.Format([]byte(input)) + + if err != nil { + t.Fatalf("Format error: %v", err) + } + + if string(result) != expected { + t.Errorf("got:\n%s\nwant:\n%s", result, expected) + } +} + +func TestFormat_ForLoop(t *testing.T) { + input := `package main + +func main() { + x := 1 + for i := 0; i < 10; i++ { + y := i + } + z := 2 +} +` + expected := `package main + +func main() { + x := 1 + + for i := 0; i < 10; i++ { + y := i + } + + z := 2 +} +` + f := &Formatter{CommentMode: CommentsFollow} + result, err := f.Format([]byte(input)) + + if err != nil { + t.Fatalf("Format error: %v", err) + } + + if string(result) != expected { + t.Errorf("got:\n%s\nwant:\n%s", result, expected) + } +} + +func TestFormat_Switch(t *testing.T) { + input := `package main + +func main() { + x := 1 + switch x { + case 1: + y := 2 + } + z := 3 +} +` + expected := `package main + +func main() { + x := 1 + + switch x { + case 1: + y := 2 + } + + z := 3 +} +` + f := &Formatter{CommentMode: CommentsFollow} + result, err := f.Format([]byte(input)) + + if err != nil { + t.Fatalf("Format error: %v", err) + } + + if string(result) != expected { + t.Errorf("got:\n%s\nwant:\n%s", result, expected) + } +} + +func TestFormat_MultipleFunctions(t *testing.T) { + input := `package main + +func foo() { + x := 1 +} + + +func bar() { + y := 2 +} +` + expected := `package main + +func foo() { + x := 1 +} + +func bar() { + y := 2 +} +` + f := &Formatter{CommentMode: CommentsFollow} + result, err := f.Format([]byte(input)) + + if err != nil { + t.Fatalf("Format error: %v", err) + } + + if string(result) != expected { + t.Errorf("got:\n%s\nwant:\n%s", result, expected) + } +} + +func TestFormat_TypeStruct(t *testing.T) { + input := `package main + +type Foo struct { + X int +} +var x = 1 +` + expected := `package main + +type Foo struct { + X int +} + +var x = 1 +` + f := &Formatter{CommentMode: CommentsFollow} + result, err := f.Format([]byte(input)) + + if err != nil { + t.Fatalf("Format error: %v", err) + } + + if string(result) != expected { + t.Errorf("got:\n%s\nwant:\n%s", result, expected) + } +} + +func TestFormat_DifferentStatementTypes(t *testing.T) { + input := `package main + +func main() { + x := 1 + y := 2 + var a = 3 + defer cleanup() + defer cleanup2() + go worker() + return +} +` + expected := `package main + +func main() { + x := 1 + y := 2 + + var a = 3 + + defer cleanup() + defer cleanup2() + + go worker() + + return +} +` + f := &Formatter{CommentMode: CommentsFollow} + result, err := f.Format([]byte(input)) + + if err != nil { + t.Fatalf("Format error: %v", err) + } + + if string(result) != expected { + t.Errorf("got:\n%s\nwant:\n%s", result, expected) + } +} + +func TestFormat_ConsecutiveIfs(t *testing.T) { + input := `package main + +func main() { + if err != nil { + return + } + if x > 0 { + y = 1 + } +} +` + expected := `package main + +func main() { + if err != nil { + return + } + + if x > 0 { + y = 1 + } +} +` + f := &Formatter{CommentMode: CommentsFollow} + result, err := f.Format([]byte(input)) + + if err != nil { + t.Fatalf("Format error: %v", err) + } + + if string(result) != expected { + t.Errorf("got:\n%s\nwant:\n%s", result, expected) + } +} + +func TestFormat_CaseClauseStatements(t *testing.T) { + input := `package main + +func main() { + switch x { + case 1: + foo() + if err != nil { + return + } + } +} +` + expected := `package main + +func main() { + switch x { + case 1: + foo() + + if err != nil { + return + } + } +} +` + f := &Formatter{CommentMode: CommentsFollow} + result, err := f.Format([]byte(input)) + + if err != nil { + t.Fatalf("Format error: %v", err) + } + + if string(result) != expected { + t.Errorf("got:\n%s\nwant:\n%s", result, expected) + } +} + +func TestFormat_DeferWithInlineFunc(t *testing.T) { + input := `package main + +func main() { + defer func() { _ = file.Close() }() + fileInfo, err := file.Stat() +} +` + expected := `package main + +func main() { + defer func() { _ = file.Close() }() + + fileInfo, err := file.Stat() +} +` + f := &Formatter{CommentMode: CommentsFollow} + result, err := f.Format([]byte(input)) + + if err != nil { + t.Fatalf("Format error: %v", err) + } + + if string(result) != expected { + t.Errorf("got:\n%s\nwant:\n%s", result, expected) + } +} + +func TestFormat_CaseClauseConsecutiveAssignments(t *testing.T) { + input := `package main + +func main() { + switch x { + case "user": + roleStyle = UserStyle + contentStyle = ContentStyle + prefix = "You" + case "assistant": + roleStyle = AssistantStyle + } +} +` + expected := `package main + +func main() { + switch x { + case "user": + roleStyle = UserStyle + contentStyle = ContentStyle + prefix = "You" + case "assistant": + roleStyle = AssistantStyle + } +} +` + f := &Formatter{CommentMode: CommentsFollow} + result, err := f.Format([]byte(input)) + + if err != nil { + t.Fatalf("Format error: %v", err) + } + + if string(result) != expected { + t.Errorf("got:\n%s\nwant:\n%s", result, expected) + } +} @@ -0,0 +1,3 @@ +module github.com/Fuwn/iku + +go 1.25.6 @@ -0,0 +1,235 @@ +package main + +import ( + "bytes" + "flag" + "fmt" + "io" + "os" + "path/filepath" + "runtime" + "strings" + "sync" +) + +var version = "dev" + +var ( + writeFlag = flag.Bool("w", false, "write result to (source) file instead of stdout") + listFlag = flag.Bool("l", false, "list files whose formatting differs from iku's") + diffFlag = flag.Bool("d", false, "display diffs instead of rewriting files") + commentsFlag = flag.String("comments", "follow", "comment attachment mode: follow, precede, standalone") + versionFlag = flag.Bool("version", false, "print version") +) + +func main() { + flag.Usage = func() { + fmt.Fprintf(os.Stderr, "usage: iku [flags] [path ...]\n") + flag.PrintDefaults() + } + + flag.Parse() + + if *versionFlag { + fmt.Println("iku", version) + os.Exit(0) + } + + commentMode, err := parseCommentMode(*commentsFlag) + + if err != nil { + fmt.Fprintf(os.Stderr, "iku: %v\n", err) + os.Exit(2) + } + + formatter := &Formatter{CommentMode: commentMode} + + if flag.NArg() == 0 { + if *writeFlag { + fmt.Fprintln(os.Stderr, "iku: cannot use -w with standard input") + os.Exit(2) + } + + if err := processFile(formatter, "<stdin>", os.Stdin, os.Stdout, false); err != nil { + fmt.Fprintf(os.Stderr, "iku: %v\n", err) + os.Exit(1) + } + + return + } + + exitCode := 0 + + for _, path := range flag.Args() { + switch info, err := os.Stat(path); { + case err != nil: + fmt.Fprintf(os.Stderr, "iku: %v\n", err) + + exitCode = 1 + case info.IsDir(): + if err := processDir(formatter, path, &exitCode); err != nil { + fmt.Fprintf(os.Stderr, "iku: %v\n", err) + + exitCode = 1 + } + default: + if err := processFilePath(formatter, path, &exitCode); err != nil { + fmt.Fprintf(os.Stderr, "iku: %v\n", err) + + exitCode = 1 + } + } + } + + os.Exit(exitCode) +} + +func parseCommentMode(mode string) (CommentMode, error) { + switch strings.ToLower(mode) { + case "follow": + return CommentsFollow, nil + case "precede": + return CommentsPrecede, nil + case "standalone": + return CommentsStandalone, nil + default: + return 0, fmt.Errorf("invalid comment mode: %q (use follow, precede, or standalone)", mode) + } +} + +func processDir(formatter *Formatter, directory string, exitCode *int) error { + var files []string + + err := filepath.Walk(directory, func(path string, info os.FileInfo, err error) error { + if err != nil { + return err + } + + if !info.IsDir() && strings.HasSuffix(path, ".go") { + files = append(files, path) + } + + return nil + }) + + if err != nil { + return err + } + + var waitGroup sync.WaitGroup + var mutex sync.Mutex + + semaphore := make(chan struct{}, runtime.NumCPU()) + + for _, path := range files { + waitGroup.Add(1) + + go func(filePath string) { + defer waitGroup.Done() + + semaphore <- struct{}{} + + defer func() { <-semaphore }() + + if err := processFilePath(formatter, filePath, exitCode); err != nil { + mutex.Lock() + fmt.Fprintf(os.Stderr, "iku: %v\n", err) + + *exitCode = 1 + + mutex.Unlock() + } + }(path) + } + + waitGroup.Wait() + + return nil +} + +func processFilePath(formatter *Formatter, path string, _ *int) error { + file, err := os.Open(path) + + if err != nil { + return err + } + + defer func() { _ = file.Close() }() + + var output io.Writer = os.Stdout + + if *writeFlag { + output = nil + } + + return processFile(formatter, path, file, output, true) +} + +func processFile(formatter *Formatter, filename string, input io.Reader, outputWriter io.Writer, isFile bool) error { + source, err := io.ReadAll(input) + + if err != nil { + return fmt.Errorf("%s: %v", filename, err) + } + + result, err := formatter.Format(source) + + if err != nil { + return fmt.Errorf("%s: %v", filename, err) + } + + if *listFlag { + if !bytes.Equal(source, result) { + fmt.Println(filename) + } + + return nil + } + + if *diffFlag { + if !bytes.Equal(source, result) { + difference := unifiedDiff(filename, source, result) + _, _ = os.Stdout.Write(difference) + } + + return nil + } + + if *writeFlag && isFile { + if !bytes.Equal(source, result) { + return os.WriteFile(filename, result, 0644) + } + + return nil + } + + if outputWriter != nil { + _, err = outputWriter.Write(result) + + return err + } + + return nil +} + +func unifiedDiff(filename string, original, formatted []byte) []byte { + var buffer bytes.Buffer + + fmt.Fprintf(&buffer, "--- %s\n", filename) + fmt.Fprintf(&buffer, "+++ %s\n", filename) + + originalLines := strings.Split(string(original), "\n") + formattedLines := strings.Split(string(formatted), "\n") + + fmt.Fprintf(&buffer, "@@ -1,%d +1,%d @@\n", len(originalLines), len(formattedLines)) + + for _, line := range originalLines { + fmt.Fprintf(&buffer, "-%s\n", line) + } + + for _, line := range formattedLines { + fmt.Fprintf(&buffer, "+%s\n", line) + } + + return buffer.Bytes() +} |