add comments

pkg/errs/error.go

@@ -1,15 +1,23 @@
 package errs
 
+// ErrorCategory represents error category
 type ErrorCategory int
 
+// Error categories
 const (
 	CATEGORY_SYSTEM ErrorCategory = 1
 	CATEGORY_NORMAL ErrorCategory = 2
+)
 
+// Sub categories of system error
+const (
 	SYSTEM_SUBCATEGORY_DEFAULT  = 0
 	SYSTEM_SUBCATEGORY_SETTING  = 1
 	SYSTEM_SUBCATEGORY_DATABASE = 2
+)
 
+// Sub categories of normal error
+const (
 	NORMAL_SUBCATEGORY_GLOBAL      = 0
 	NORMAL_SUBCATEGORY_USER        = 1
 	NORMAL_SUBCATEGORY_TOKEN       = 2
@@ -20,6 +28,7 @@ const (
 	NORMAL_SUBCATEGORY_TAG         = 7
 )
 
+// Error represents the specific error returned to user
 type Error struct {
 	Category       ErrorCategory
 	SubCategory    int
@@ -29,14 +38,17 @@ type Error struct {
 	BaseError      []error
 }
 
+// Error returns the error message
 func (err *Error) Error() string {
 	return err.Message
 }
 
+// Code returns the error code
 func (err *Error) Code() int {
 	return int(err.Category)*100000 + err.SubCategory*1000 + err.Index
 }
 
+// New returns a new error instance
 func New(category ErrorCategory, subCategory int, index int, httpStatusCode int, message string, baseError ...error) *Error {
 	return &Error{
 		Category:       category,
@@ -48,14 +60,17 @@ func New(category ErrorCategory, subCategory int, index int, httpStatusCode int,
 	}
 }
 
+// NewSystemError returns a new system error instance
 func NewSystemError(subCategory int, index int, httpStatusCode int, message string) *Error {
 	return New(CATEGORY_SYSTEM, subCategory, index, httpStatusCode, message)
 }
 
+// NewNormalError returns a new normal error instance
 func NewNormalError(subCategory int, index int, httpStatusCode int, message string) *Error {
 	return New(CATEGORY_NORMAL, subCategory, index, httpStatusCode, message)
 }
 
+// NewIncompleteOrIncorrectSubmissionError returns a new incomplete or incorrect submission error instance
 func NewIncompleteOrIncorrectSubmissionError(err error) *Error {
 	return New(ErrIncompleteOrIncorrectSubmission.Category,
 		ErrIncompleteOrIncorrectSubmission.SubCategory,
@@ -64,6 +79,8 @@ func NewIncompleteOrIncorrectSubmissionError(err error) *Error {
 		ErrIncompleteOrIncorrectSubmission.Message, err)
 }
 
+// Or would return the error from err parameter if the this error is defined in this project,
+// or return the default error
 func Or(err error, defaultErr *Error) *Error {
 	if finalError, ok := err.(*Error); ok {
 		return finalError
@@ -72,6 +89,7 @@ func Or(err error, defaultErr *Error) *Error {
 	}
 }
 
+// IsCustomError returns whether this error is defined in this project
 func IsCustomError(err error) bool {
 	_, ok := err.(*Error)
 	return ok