feat: improvements in entity domain logic

domain/entity/book.go

@@ -27,12 +27,16 @@ func NewBook(title string, author string, pages int, quantity int) (*Book, error
 		Quantity:  quantity,
 		CreatedAt: time.Now(),
 	}
+	err := b.Validate()
+	if err != nil {
+		return nil, domain.ErrInvalidEntity
+	}
 	return b, nil
 }
 
 //Validate validate book
 func (b *Book) Validate() error {
-	if b.Title == "" || b.Author == "" || b.Pages <= 0 {
+	if b.Title == "" || b.Author == "" || b.Pages <= 0 || b.Quantity <= 0 {
 		return domain.ErrInvalidEntity
 	}
 	return nil

domain/entity/book_test.go

@@ -9,7 +9,7 @@ import (
 )
 
 func TestNewBook(t *testing.T) {
-	b, err := entity.NewBook("American Gods", "Neil Gaiman", 100, 0)
+	b, err := entity.NewBook("American Gods", "Neil Gaiman", 100, 1)
 	assert.Nil(t, err)
 	assert.Equal(t, b.Title, "American Gods")
 	assert.NotNil(t, b.ID)
@@ -37,7 +37,7 @@ func TestBookValidate(t *testing.T) {
 			author:   "Neil Gaiman",
 			pages:    100,
 			quantity: 0,
-			want:     nil,
+			want:     domain.ErrInvalidEntity,
 		},
 		{
 			title:    "",
@@ -63,8 +63,7 @@ func TestBookValidate(t *testing.T) {
 	}
 	for _, tc := range tests {
 
-		b, err := entity.NewBook(tc.title, tc.author, tc.pages, tc.quantity)
-		err = b.Validate()
+		_, err := entity.NewBook(tc.title, tc.author, tc.pages, tc.quantity)
 		assert.Equal(t, err, tc.want)
 	}
 

domain/entity/user.go

@@ -19,8 +19,9 @@ type User struct {
 	Books     []ID
 }
 
+//NewUser create a new user
 func NewUser(email, password, firstName, lastName string) (*User, error) {
-	e := &User{
+	u := &User{
 		ID:        NewID(),
 		Email:     email,
 		FirstName: firstName,
@@ -31,15 +32,25 @@ func NewUser(email, password, firstName, lastName string) (*User, error) {
 	if err != nil {
 		return nil, err
 	}
-	e.Password = pwd
-	return e, nil
+	u.Password = pwd
+	err = u.Validate()
+	if err != nil {
+		return nil, domain.ErrInvalidEntity
+	}
+	return u, nil
 }
 
+//AddBook add a book
 func (u *User) AddBook(id ID) error {
+	_, err := u.GetBook(id)
+	if err == nil {
+		return domain.ErrBookAlreadyBorrowed
+	}
 	u.Books = append(u.Books, id)
 	return nil
 }
 
+//RemoveBook remove a book
 func (u *User) RemoveBook(id ID) error {
 	for i, j := range u.Books {
 		if j == id {
@@ -50,6 +61,7 @@ func (u *User) RemoveBook(id ID) error {
 	return domain.ErrNotFound
 }
 
+//GetBook get a book
 func (u *User) GetBook(id ID) (ID, error) {
 	for _, v := range u.Books {
 		if v == id {
@@ -59,6 +71,7 @@ func (u *User) GetBook(id ID) (ID, error) {
 	return id, domain.ErrNotFound
 }
 
+//Validate validate data
 func (u *User) Validate() error {
 	if u.Email == "" || u.FirstName == "" || u.LastName == "" || u.Password == "" {
 		return domain.ErrInvalidEntity
@@ -67,6 +80,7 @@ func (u *User) Validate() error {
 	return nil
 }
 
+//ValidatePassword
 func (u *User) ValidatePassword(p string) error {
 	err := bcrypt.CompareHashAndPassword([]byte(u.Password), []byte(p))
 	if err != nil {

domain/entity/user_test.go

@@ -27,9 +27,13 @@ func TestValidatePassword(t *testing.T) {
 
 func TestAddBook(t *testing.T) {
 	u, _ := entity.NewUser("sjobs@apple.com", "new_password", "Steve", "Jobs")
-	err := u.AddBook(entity.NewID())
+	bID := entity.NewID()
+	err := u.AddBook(bID)
 	assert.Nil(t, err)
 	assert.Equal(t, 1, len(u.Books))
+	err = u.AddBook(bID)
+	assert.Equal(t, domain.ErrBookAlreadyBorrowed, err)
+
 }
 
 func TestRemoveBook(t *testing.T) {
@@ -101,8 +105,7 @@ func TestUserValidate(t *testing.T) {
 	}
 	for _, tc := range tests {
 
-		u, err := entity.NewUser(tc.email, tc.password, tc.firstName, tc.lastName)
-		err = u.Validate()
+		_, err := entity.NewUser(tc.email, tc.password, tc.firstName, tc.lastName)
 		assert.Equal(t, err, tc.want)
 	}
 

domain/usecase/book/mock/book.go

@@ -5,10 +5,9 @@
 package mock
 
 import (
-	reflect "reflect"
-
 	entity "github.com/eminetto/clean-architecture-go-v2/domain/entity"
 	gomock "github.com/golang/mock/gomock"
+	reflect "reflect"
 )
 
 // MockReader is a mock of Reader interface

domain/usecase/book/service.go

@@ -27,10 +27,6 @@ func (s *Service) CreateBook(title string, author string, pages int, quantity in
 	if err != nil {
 		return b.ID, err
 	}
-	err = b.Validate()
-	if err != nil {
-		return b.ID, err
-	}
 	return s.repo.Create(b)
 }
 

domain/usecase/loan/mock/loan.go

@@ -5,10 +5,9 @@
 package mock
 
 import (
-	reflect "reflect"
-
 	entity "github.com/eminetto/clean-architecture-go-v2/domain/entity"
 	gomock "github.com/golang/mock/gomock"
+	reflect "reflect"
 )
 
 // MockUseCase is a mock of UseCase interface

domain/usecase/loan/service.go

@@ -35,10 +35,6 @@ func (s *Service) Borrow(u *entity.User, b *entity.Book) error {
 		return domain.ErrNotEnoughBooks
 	}
 
-	_, err = u.GetBook(b.ID)
-	if err == nil {
-		return domain.ErrBookAlreadyBorrowed
-	}
 	err = u.AddBook(b.ID)
 	if err != nil {
 		return err

domain/usecase/user/mock/user.go

@@ -5,10 +5,9 @@
 package mock
 
 import (
-	reflect "reflect"
-
 	entity "github.com/eminetto/clean-architecture-go-v2/domain/entity"
 	gomock "github.com/golang/mock/gomock"
+	reflect "reflect"
 )
 
 // MockReader is a mock of Reader interface

domain/usecase/user/service.go

@@ -25,11 +25,7 @@ func NewService(r Repository) *Service {
 func (s *Service) CreateUser(email, password, firstName, lastName string) (entity.ID, error) {
 	e, err := entity.NewUser(email, password, firstName, lastName)
 	if err != nil {
-		return e.ID, domain.ErrInvalidEntity
-	}
-	err = e.Validate()
-	if err != nil {
-		return e.ID, domain.ErrInvalidEntity
+		return e.ID, err
 	}
 	return s.repo.Create(e)
 }