APIv4 DELETE /users/{user_id}/posts/{post_id}/reactions/name (#6117)

* APIv4 DELETE /users/{user_id}/posts/{post_id}/reactions/name

* updated v3 deleteReaction endpoint

* update parameter of app.DeleteReactionForPost()

* update utils.IsValidAlphaNum, add utils.IsValidAlphaNumHyphenUnderscore, and add related tests

model/utils.go

@@ -297,7 +297,7 @@ var reservedName = []string{
 
 func IsValidChannelIdentifier(s string) bool {
 
-	if !IsValidAlphaNum(s, true) {
+	if !IsValidAlphaNumHyphenUnderscore(s, true) {
 		return false
 	}
 
@@ -308,22 +308,20 @@ func IsValidChannelIdentifier(s string) bool {
 	return true
 }
 
-var validAlphaNumUnderscore = regexp.MustCompile(`^[a-z0-9]+([a-z\-\_0-9]+|(__)?)[a-z0-9]+$`)
-var validAlphaNum = regexp.MustCompile(`^[a-z0-9]+([a-z\-0-9]+|(__)?)[a-z0-9]+$`)
+func IsValidAlphaNum(s string) bool {
+	validAlphaNum := regexp.MustCompile(`^[a-z0-9]+([a-z\-0-9]+|(__)?)[a-z0-9]+$`)
 
-func IsValidAlphaNum(s string, allowUnderscores bool) bool {
-	var match bool
-	if allowUnderscores {
-		match = validAlphaNumUnderscore.MatchString(s)
-	} else {
-		match = validAlphaNum.MatchString(s)
+	return validAlphaNum.MatchString(s)
+}
+
+func IsValidAlphaNumHyphenUnderscore(s string, withFormat bool) bool {
+	if withFormat {
+		validAlphaNumHyphenUnderscore := regexp.MustCompile(`^[a-z0-9]+([a-z\-\_0-9]+|(__)?)[a-z0-9]+$`)
+		return validAlphaNumHyphenUnderscore.MatchString(s)
 	}
 
-	if !match {
-		return false
-	}
-
-	return true
+	validSimpleAlphaNumHyphenUnderscore := regexp.MustCompile(`^[a-zA-Z0-9\-_]+$`)
+	return validSimpleAlphaNumHyphenUnderscore.MatchString(s)
 }
 
 func Etag(parts ...interface{}) string {