Beautified error messages

models/books_add_update.go

@@ -19,7 +19,7 @@ sie in die Datenbank eingetragen und mit dem Buch verknüpft.
 func AddOrUpdateBook(book Book) (newBook Book, err error) {
 
 	// Check if we have at least a booktitle when we're inserting a new book
-	if book.Title == ""{
+	if book.Title == "" {
 		return Book{}, ErrBookTitleCannotBeEmpty{}
 	}
 

models/error.go

@@ -37,10 +37,10 @@ func (err ErrNoUsername) Error() string {
 	return fmt.Sprintf("you need to specify a username [user id: %d]", err.UserID)
 }
 
-// ErrNoUsernamePassword represents a "UsernameAlreadyExists" kind of error.
-type ErrNoUsernamePassword struct {}
+// ErrNoUsernamePassword represents a "NoUsernamePassword" kind of error.
+type ErrNoUsernamePassword struct{}
 
-// IsErrNoUsernamePassword checks if an error is a ErrUsernameExists.
+// IsErrNoUsernamePassword checks if an error is a ErrNoUsernamePassword.
 func IsErrNoUsernamePassword(err error) bool {
 	_, ok := err.(ErrNoUsernamePassword)
 	return ok
@@ -50,12 +50,12 @@ func (err ErrNoUsernamePassword) Error() string {
 	return fmt.Sprintf("you need to specify a username and a password")
 }
 
-// ErrUserDoesNotExist represents a "UsernameAlreadyExists" kind of error.
+// ErrUserDoesNotExist represents a "UserDoesNotExist" kind of error.
 type ErrUserDoesNotExist struct {
 	UserID int64
 }
 
-// IsErrUserDoesNotExist checks if an error is a ErrUsernameExists.
+// IsErrUserDoesNotExist checks if an error is a ErrUserDoesNotExist.
 func IsErrUserDoesNotExist(err error) bool {
 	_, ok := err.(ErrUserDoesNotExist)
 	return ok
@@ -65,10 +65,27 @@ func (err ErrUserDoesNotExist) Error() string {
 	return fmt.Sprintf("this user does not exist [user id: %d]", err.UserID)
 }
 
-// ErrIDCannotBeZero represents a "UsernameAlreadyExists" kind of error.
-type ErrIDCannotBeZero struct {}
+// ErrCouldNotGetUserID represents a "ErrCouldNotGetUserID" kind of error.
+type ErrCouldNotGetUserID struct{}
 
-// IsErrIDCannotBeZero checks if an error is a ErrUsernameExists.
+// IsErrCouldNotGetUserID checks if an error is a ErrCouldNotGetUserID.
+func IsErrCouldNotGetUserID(err error) bool {
+	_, ok := err.(ErrCouldNotGetUserID)
+	return ok
+}
+
+func (err ErrCouldNotGetUserID) Error() string {
+	return fmt.Sprintf("could not get user ID")
+}
+
+// ===================
+// Empty things errors
+// ===================
+
+// ErrIDCannotBeZero represents a "IDCannotBeZero" kind of error. Used if an ID (of something, not defined) is 0 where it should not.
+type ErrIDCannotBeZero struct{}
+
+// IsErrIDCannotBeZero checks if an error is a ErrIDCannotBeZero.
 func IsErrIDCannotBeZero(err error) bool {
 	_, ok := err.(ErrIDCannotBeZero)
 	return ok
@@ -79,9 +96,9 @@ func (err ErrIDCannotBeZero) Error() string {
 }
 
 // ErrAuthorCannotBeEmpty represents a "AuthorCannotBeEmpty" kind of error.
-type ErrAuthorCannotBeEmpty struct {}
+type ErrAuthorCannotBeEmpty struct{}
 
-// IsErrIDCannotBeZero checks if an error is a ErrUsernameExists.
+// IsErrAuthorCannotBeEmpty checks if an error is a ErrAuthorCannotBeEmpty.
 func IsErrAuthorCannotBeEmpty(err error) bool {
 	_, ok := err.(ErrAuthorCannotBeEmpty)
 	return ok
@@ -92,7 +109,7 @@ func (err ErrAuthorCannotBeEmpty) Error() string {
 }
 
 // ErrItemTitleCannotBeEmpty represents a "ErrItemTitleCannotBeEmpty" kind of error.
-type ErrItemTitleCannotBeEmpty struct {}
+type ErrItemTitleCannotBeEmpty struct{}
 
 // IsErrItemTitleCannotBeEmpty checks if an error is a ErrItemTitleCannotBeEmpty.
 func IsErrItemTitleCannotBeEmpty(err error) bool {
@@ -105,9 +122,9 @@ func (err ErrItemTitleCannotBeEmpty) Error() string {
 }
 
 // ErrBookTitleCannotBeEmpty represents a "ErrBookTitleCannotBeEmpty" kind of error.
-type ErrBookTitleCannotBeEmpty struct {}
+type ErrBookTitleCannotBeEmpty struct{}
 
-// ErrBookTitleCannotBeEmpty checks if an error is a ErrBookTitleCannotBeEmpty.
+// IsErrBookTitleCannotBeEmpty checks if an error is a ErrBookTitleCannotBeEmpty.
 func IsErrBookTitleCannotBeEmpty(err error) bool {
 	_, ok := err.(ErrBookTitleCannotBeEmpty)
 	return ok
@@ -117,21 +134,8 @@ func (err ErrBookTitleCannotBeEmpty) Error() string {
 	return fmt.Sprintf("the book should at least have a title")
 }
 
-// ErrCouldNotGetUserID represents a "ErrCouldNotGetUserID" kind of error.
-type ErrCouldNotGetUserID struct {}
-
-// ErrBookTitleCannotBeEmpty checks if an error is a ErrBookTitleCannotBeEmpty.
-func IsErrCouldNotGetUserID(err error) bool {
-	_, ok := err.(ErrCouldNotGetUserID)
-	return ok
-}
-
-func (err ErrCouldNotGetUserID) Error() string {
-	return fmt.Sprintf("could not get user ID")
-}
-
 // ErrNoPublisherName represents a "ErrNoPublisherName" kind of error.
-type ErrNoPublisherName struct {}
+type ErrNoPublisherName struct{}
 
 // IsErrNoPublisherName checks if an error is a ErrNoPublisherName.
 func IsErrNoPublisherName(err error) bool {

routes/api/v1/authors_add_update.go

@@ -63,7 +63,7 @@ func AuthorAddOrUpdate(c echo.Context) error {
 
 	if err != nil {
 		if models.IsErrAuthorCannotBeEmpty(err) {
-			return c.JSON(http.StatusBadRequest, models.Message{"Id cannot be 0"})
+			return c.JSON(http.StatusBadRequest, models.Message{"Please provide at least a name and a lastname."})
 		}
 		return c.JSON(http.StatusInternalServerError, models.Message{"Error"})
 	}