Add unit test

README.md

@@ -3,7 +3,12 @@
 [![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 works both as a library and as a CLI. Both will automatically generate files with Value Objects defined.
+[![Go Reference](https://pkg.go.dev/badge/github.com/nao1215/vogen.svg)](https://pkg.go.dev/github.com/nao1215/vogen)
+![Coverage](https://raw.githubusercontent.com/nao1215/octocovs-central-repo/main/badges/nao1215/vogen/coverage.svg)
+[![reviewdog](https://github.com/nao1215/vogen/actions/workflows/reviewdog.yml/badge.svg)](https://github.com/nao1215/vogen/actions/workflows/reviewdog.yml)
+[![MultiPlatformUnitTest](https://github.com/nao1215/vogen/actions/workflows/unit_test.yml/badge.svg)](https://github.com/nao1215/vogen/actions/workflows/unit_test.yml)
+
+The vogen library is to generate value objects in golang. The vogen 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.
 

vogen.go

@@ -96,7 +96,7 @@ func (vo *Vogen) validate(vos ...ValueObject) error {
 			return ErrStructNameEmpty
 		}
 		if len(v.Fields) == 0 {
-			return ErrInvalidFieldName
+			return ErrInvalidField
 		}
 		for _, f := range v.Fields {
 			if f.Name == "" {

vogen_test.go

@@ -0,0 +1,96 @@
+// Package vogen provides a code generator for Value Objects in Go.
+// Value Objects are immutable objects that represent a value.
+package vogen
+
+import (
+	"errors"
+	"testing"
+)
+
+func TestNew(t *testing.T) {
+	t.Parallel()
+
+	t.Run("error occurs when the file path is not set", func(t *testing.T) {
+		t.Parallel()
+
+		_, err := New(WithFilePath(""))
+		if !errors.Is(err, ErrInvalidFilePath) {
+			t.Errorf("want: %v, got: %v", ErrInvalidFilePath, err)
+		}
+	})
+
+	t.Run("error occurs when the package name is not set", func(t *testing.T) {
+		t.Parallel()
+
+		_, err := New(WithPackageName(""))
+		if !errors.Is(err, ErrInvalidPackageName) {
+			t.Errorf("want: %v, got: %v", ErrInvalidPackageName, err)
+		}
+	})
+}
+
+func TestVogen_AppendValueObjects(t *testing.T) {
+	t.Parallel()
+
+	t.Run("error occurs when the StructName is not set", func(t *testing.T) {
+		t.Parallel()
+
+		gen, _ := New()
+		err := gen.AppendValueObjects(ValueObject{
+			StructName: "",
+			Fields: []Field{
+				{Name: "Name", Type: "string"},
+			},
+			Comments: []string{"test comment"},
+		})
+		if !errors.Is(err, ErrStructNameEmpty) {
+			t.Errorf("want: %v, got: %v", ErrStructNameEmpty, err)
+		}
+	})
+
+	t.Run("error occurs when the Field is not set", func(t *testing.T) {
+		t.Parallel()
+
+		gen, _ := New()
+		err := gen.AppendValueObjects(ValueObject{
+			StructName: "Person",
+			Fields:     nil,
+			Comments:   []string{"test comment"},
+		})
+		if !errors.Is(err, ErrInvalidField) {
+			t.Errorf("want: %v, got: %v", ErrInvalidField, err)
+		}
+	})
+
+	t.Run("error occurs when the Field 'Name' is not set", func(t *testing.T) {
+		t.Parallel()
+
+		gen, _ := New()
+		err := gen.AppendValueObjects(ValueObject{
+			StructName: "Person",
+			Fields: []Field{
+				{Name: "", Type: "string"},
+			},
+			Comments: []string{"test comment"},
+		})
+		if !errors.Is(err, ErrInvalidFieldName) {
+			t.Errorf("want: %v, got: %v", ErrInvalidFieldName, err)
+		}
+	})
+
+	t.Run("error occurs when the Field 'Type' is not set", func(t *testing.T) {
+		t.Parallel()
+
+		gen, _ := New()
+		err := gen.AppendValueObjects(ValueObject{
+			StructName: "Person",
+			Fields: []Field{
+				{Name: "Name", Type: ""},
+			},
+			Comments: []string{"test comment"},
+		})
+		if !errors.Is(err, ErrInvalidFieldType) {
+			t.Errorf("want: %v, got: %v", ErrInvalidFieldType, err)
+		}
+	})
+}