Changed to manage generated target code with []string instead of buffer.

.github/ISSUE_TEMPLATE/bug_report.md

@@ -7,7 +7,7 @@ assignees: ''
 
 ---
 
-## gup version**
+## vogen version**
 v0.y.z
 
 ## Description (About the problem)

.github/workflows/coverage.yml

@@ -0,0 +1,31 @@
+name: Coverage
+
+on:
+  workflow_dispatch:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  unit_test:
+    name: Unit test (linux)
+
+    strategy:
+      matrix:
+        platform: [ubuntu-latest]
+
+    runs-on: ${{ matrix.platform }}
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version: "1"
+          check-latest: true
+
+      - name: Run tests with coverage report output
+        run: go test -cover -coverpkg=./... -coverprofile=coverage.out ./...
+
+      - uses: k1LoW/octocov-action@v1

.github/workflows/unit_test.yml

@@ -21,8 +21,6 @@ jobs:
           - "1"
           - "1.23"
           - "1.22"
-          - "1.21"
-          - "1.20"
       fail-fast: false
     runs-on: ${{ matrix.os }}
 

.gitignore

@@ -26,4 +26,4 @@ go.work.sum
 
 # Test file
 testdata/example_output.go
-coverage.*
+/coverage.*

.golangci.yml

@@ -1,5 +1,5 @@
 run:
-  go: "1.21"
+  go: "1.22"
 
 issues:
   exclude-use-default: false

README.md

@@ -3,16 +3,16 @@
 [![All Contributors](https://img.shields.io/badge/all_contributors-1-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
-The vogen is a tool to generate value objects in golang.
+The vogen is a tool to generate value objects in golang. The vogen works both as a library and as a CLI. Both will automatically generate files with Value Objects defined.
 
 In golang, the only way to implement Value Objects is to use structs. Implementing Getter and Equal() on a newly defined Value Object (structure) is a simple and tedious task. The vogen package simplifies that task.
 
-### Supported OS and go version
+## Supported OS and go version
 - OS: Linux, macOS, Windows
-- Go: 1.21 or later
+- Go: 1.22 or later
 
-### Example
-#### Implement a value object metadata
+## Example
+### Implement a value object metadata
 
 Firstly, write your value object metadata. Here is an example: gen/main.go
 
@@ -135,4 +135,4 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
 
 <!-- ALL-CONTRIBUTORS-LIST:END -->
 
-This project follows the [all-contributors](https://github.com/all-contributors/all-contributors) specification. Contributions of any kind welcome!
+This project follows the [all-contributors](https://github.com/all-contributors/all-contributors) specification. Contributions of any kind welcome!

go.mod

@@ -1,3 +1,3 @@
 module github.com/nao1215/vogen
 
-go 1.21
+go 1.22

vogen.go

@@ -3,7 +3,6 @@
 package vogen
 
 import (
-	"bytes"
 	"fmt"
 	"go/format"
 	"os"
@@ -52,15 +51,17 @@ type Vogen struct {
 	packageName string
 	// valueObjects is the list of valueObjects to be generated.
 	valueObjects []ValueObject
-	// buf is the buffer to write the generated code.
-	buf bytes.Buffer
+	// code is the list of code to be generated.
+	code []string
 }
 
 // New creates a new Vogen struct.
 func New(opts ...Option) (*Vogen, error) {
 	vogen := &Vogen{
-		filePath:    "value_object.go",
-		packageName: "vo",
+		filePath:     "value_object.go",
+		packageName:  "vo",
+		valueObjects: []ValueObject{},
+		code:         []string{},
 	}
 	for _, opt := range opts {
 		if err := opt(vogen); err != nil {
@@ -103,164 +104,85 @@ func (vo *Vogen) validate(vos ...ValueObject) error {
 
 // Generate generates ValueObject code and writes it to the specified file path.
 func (vo *Vogen) Generate() error {
-	vo.buf.Reset()
-
-	if err := vo.writePackage(); err != nil {
-		return fmt.Errorf("failed to write package declaration: %w", err)
-	}
-
-	if err := vo.writeImports(); err != nil {
-		return fmt.Errorf("failed to write imports: %w", err)
-	}
+	vo.code = append(vo.code, "// Code generated by vogen. DO NOT EDIT.\n")
+	vo.code = append(vo.code, fmt.Sprintf("package %s\n\n", vo.packageName))
+	vo.writeImports()
 
 	for _, valueObject := range vo.valueObjects {
-		if err := vo.writeStruct(valueObject); err != nil {
-			return fmt.Errorf("failed to write struct for %s: %w", valueObject.StructName, err)
-		}
-
-		if err := vo.writeConstructor(valueObject); err != nil {
-			return fmt.Errorf("failed to write constructor for %s: %w", valueObject.StructName, err)
-		}
-
-		if err := vo.writeGetters(valueObject); err != nil {
-			return fmt.Errorf("failed to write getters for %s: %w", valueObject.StructName, err)
-		}
-
-		if err := vo.writeEqualMethod(valueObject); err != nil {
-			return fmt.Errorf("failed to write Equal method for %s: %w", valueObject.StructName, err)
-		}
-	}
-
-	if err := vo.generateFile(); err != nil {
-		return fmt.Errorf("failed to generate file: %w", err)
-	}
-
-	return nil
-}
-
-// writePackage writes the package declaration.
-func (vo *Vogen) writePackage() error {
-	if _, err := vo.buf.WriteString("// Code generated by vogen. DO NOT EDIT.\n"); err != nil {
-		return err
+		vo.writeStruct(valueObject)
+		vo.writeConstructor(valueObject)
+		vo.writeGetters(valueObject)
+		vo.writeEqualMethod(valueObject)
 	}
-	if _, err := vo.buf.WriteString(fmt.Sprintf("package %s\n\n", vo.packageName)); err != nil {
-		return err
-	}
-	return nil
+	return vo.generateFile()
 }
 
-// writeImports writes the import statements, deduplicating imports.
-func (vo *Vogen) writeImports() error {
+// writeImports writes the import statements to the code.
+func (vo *Vogen) writeImports() {
 	importSet := map[string]struct{}{}
 	for _, valueObject := range vo.valueObjects {
 		for _, imp := range valueObject.Imports {
 			importSet[imp] = struct{}{}
 		}
 	}
-
 	if len(importSet) > 0 {
-		if _, err := vo.buf.WriteString("import (\n"); err != nil {
-			return err
-		}
+		vo.code = append(vo.code, "import (\n")
 		for imp := range importSet {
-			if _, err := vo.buf.WriteString(fmt.Sprintf("\t\"%s\"\n", imp)); err != nil {
-				return err
-			}
-		}
-		if _, err := vo.buf.WriteString(")\n\n"); err != nil {
-			return err
+			vo.code = append(vo.code, fmt.Sprintf("\t\"%s\"\n", imp))
 		}
+		vo.code = append(vo.code, ")\n\n")
 	}
-	return nil
 }
 
-// writeStruct writes the struct definition for a ValueObject.
-func (vo *Vogen) writeStruct(valueObject ValueObject) error {
-	if _, err := vo.buf.WriteString(fmt.Sprintf("// %s represents a value object.\n", valueObject.StructName)); err != nil {
-		return err
-	}
-	if _, err := vo.buf.WriteString(fmt.Sprintf("type %s struct {\n", valueObject.StructName)); err != nil {
-		return err
-	}
+// writeStruct writes the struct to the code.
+func (vo *Vogen) writeStruct(valueObject ValueObject) {
+	vo.code = append(vo.code, fmt.Sprintf("// %s represents a value object.\n", valueObject.StructName))
+	vo.code = append(vo.code, fmt.Sprintf("type %s struct {\n", valueObject.StructName))
 	for _, field := range valueObject.Fields {
-		if _, err := vo.buf.WriteString(fmt.Sprintf("\t%s %s\n", field.lowercaseName(), field.Type)); err != nil {
-			return err
-		}
-	}
-	if _, err := vo.buf.WriteString("}\n\n"); err != nil {
-		return err
+		vo.code = append(vo.code, fmt.Sprintf("\t%s %s\n", field.lowercaseName(), field.Type))
 	}
-	return nil
+	vo.code = append(vo.code, "}\n\n")
 }
 
-// writeConstructor writes the constructor function for a ValueObject.
-func (vo *Vogen) writeConstructor(valueObject ValueObject) error {
+// writeConstructor writes the constructor to the code.
+func (vo *Vogen) writeConstructor(valueObject ValueObject) {
 	constructorArgs := []string{}
 	constructorInit := []string{}
 	for _, field := range valueObject.Fields {
 		constructorArgs = append(constructorArgs, fmt.Sprintf("%s %s", field.lowercaseName(), field.Type))
 		constructorInit = append(constructorInit, fmt.Sprintf("%s: %s", field.lowercaseName(), field.lowercaseName()))
 	}
-
-	if _, err := vo.buf.WriteString(fmt.Sprintf("// New%s creates a new instance of %s.\n", valueObject.StructName, valueObject.StructName)); err != nil {
-		return err
-	}
-	if _, err := vo.buf.WriteString(fmt.Sprintf("func New%s(%s) %s {\n", valueObject.StructName, strings.Join(constructorArgs, ", "), valueObject.StructName)); err != nil {
-		return err
-	}
-	if _, err := vo.buf.WriteString(fmt.Sprintf("\treturn %s{%s}\n", valueObject.StructName, strings.Join(constructorInit, ", "))); err != nil {
-		return err
-	}
-	if _, err := vo.buf.WriteString("}\n\n"); err != nil {
-		return err
-	}
-	return nil
+	vo.code = append(vo.code, fmt.Sprintf("// New%s creates a new instance of %s.\n", valueObject.StructName, valueObject.StructName))
+	vo.code = append(vo.code, fmt.Sprintf("func New%s(%s) %s {\n", valueObject.StructName, strings.Join(constructorArgs, ", "), valueObject.StructName))
+	vo.code = append(vo.code, fmt.Sprintf("\treturn %s{%s}\n", valueObject.StructName, strings.Join(constructorInit, ", ")))
+	vo.code = append(vo.code, "}\n\n")
 }
 
-// writeGetters writes getter methods for each field of a ValueObject.
-func (vo *Vogen) writeGetters(valueObject ValueObject) error {
+// writeGetters writes the getter methods to the code.
+func (vo *Vogen) writeGetters(valueObject ValueObject) {
 	for _, field := range valueObject.Fields {
-		if _, err := vo.buf.WriteString(fmt.Sprintf("// %s returns the %s field.\n", field.Name, field.lowercaseName())); err != nil {
-			return err
-		}
-		if _, err := vo.buf.WriteString(fmt.Sprintf("func (o %s) %s() %s {\n", valueObject.StructName, field.Name, field.Type)); err != nil {
-			return err
-		}
-		if _, err := vo.buf.WriteString(fmt.Sprintf("\treturn o.%s\n", field.lowercaseName())); err != nil {
-			return err
-		}
-		if _, err := vo.buf.WriteString("}\n\n"); err != nil {
-			return err
-		}
+		vo.code = append(vo.code, fmt.Sprintf("// %s returns the %s field.\n", field.Name, field.lowercaseName()))
+		vo.code = append(vo.code, fmt.Sprintf("func (o %s) %s() %s {\n", valueObject.StructName, field.Name, field.Type))
+		vo.code = append(vo.code, fmt.Sprintf("\treturn o.%s\n", field.lowercaseName()))
+		vo.code = append(vo.code, "}\n\n")
 	}
-	return nil
 }
 
-// writeEqualMethod writes the Equal method for a ValueObject.
-func (vo *Vogen) writeEqualMethod(valueObject ValueObject) error {
+// writeEqualMethod writes the Equal method to the code.
+func (vo *Vogen) writeEqualMethod(valueObject ValueObject) {
 	equalChecks := []string{}
 	for _, field := range valueObject.Fields {
 		equalChecks = append(equalChecks, fmt.Sprintf("o.%s() == other.%s()", field.Name, field.Name))
 	}
-
-	if _, err := vo.buf.WriteString(fmt.Sprintf("// Equal checks if two %s objects are equal.\n", valueObject.StructName)); err != nil {
-		return err
-	}
-	if _, err := vo.buf.WriteString(fmt.Sprintf("func (o %s) Equal(other %s) bool {\n", valueObject.StructName, valueObject.StructName)); err != nil {
-		return err
-	}
-	if _, err := vo.buf.WriteString(fmt.Sprintf("\treturn %s\n", strings.Join(equalChecks, " && "))); err != nil {
-		return err
-	}
-	if _, err := vo.buf.WriteString("}\n\n"); err != nil {
-		return err
-	}
-	return nil
+	vo.code = append(vo.code, fmt.Sprintf("// Equal checks if two %s objects are equal.\n", valueObject.StructName))
+	vo.code = append(vo.code, fmt.Sprintf("func (o %s) Equal(other %s) bool {\n", valueObject.StructName, valueObject.StructName))
+	vo.code = append(vo.code, fmt.Sprintf("\treturn %s\n", strings.Join(equalChecks, " && ")))
+	vo.code = append(vo.code, "}\n\n")
 }
 
-// generateFile generates the ValueObject code and writes it to the specified file path.
+// generateFile generates the file based on the code and writes it to the specified file path.
 func (vo *Vogen) generateFile() error {
-	formattedCode, err := format.Source(vo.buf.Bytes())
+	formattedCode, err := format.Source([]byte(strings.Join(vo.code, "")))
 	if err != nil {
 		return fmt.Errorf("failed to format source code: %w", err)
 	}