fix: improve email validation using net/mail package

Author: sniperwolf

types/email.go

@@ -3,6 +3,7 @@ package types
 import (
 	"encoding/json"
 	"errors"
+	"net/mail"
 )
 
 // ErrValidationEmail is the sentinel error returned when an email fails validation
@@ -14,7 +15,7 @@ var ErrValidationEmail = errors.New("email: failed to pass regex validation")
 type Email string
 
 func (e Email) MarshalJSON() ([]byte, error) {
-	if !emailRegex.MatchString(string(e)) {
+	if _, err := mail.ParseAddress(string(e)); err != nil {
 		return nil, ErrValidationEmail
 	}
 
@@ -32,7 +33,7 @@ func (e *Email) UnmarshalJSON(data []byte) error {
 	}
 
 	*e = Email(s)
-	if !emailRegex.MatchString(s) {
+	if _, err := mail.ParseAddress(s); err != nil {
 		return ErrValidationEmail
 	}
 

types/email_test.go

@@ -22,6 +22,11 @@ func TestEmail_MarshalJSON_Validation(t *testing.T) {
 			expectedJSON:  []byte(`{"email":"validemail@openapicodegen.com"}`),
 			expectedError: nil,
 		},
+		"it should succeed marshalling a valid email and return valid JSON populated with the email with valid separators": {
+			email:         Email("validemail+with_valid-separator{like}~these*ones@openapicodegen.com"),
+			expectedJSON:  []byte(`{"email":"validemail+with_valid-separator{like}~these*ones@openapicodegen.com"}`),
+			expectedError: nil,
+		},
 		"it should fail marshalling an invalid email and return a validation error": {
 			email:         Email("invalidemail"),
 			expectedJSON:  nil,