[PLT-7701] Fix emoji names that trigger mention (#7663)

* fix emoji names that trigger mention

* remove regex and rearrange based on comment

* make ":@here:" to not trigger a mention

app/notification.go

@@ -804,11 +804,16 @@ func GetExplicitMentions(message string, keywords map[string][]string) (map[stri
 	message = removeCodeFromMessage(message)
 
 	for _, word := range strings.FieldsFunc(message, func(c rune) bool {
-		// Split on any whitespace or punctuation that can't be part of an at mention
+		// Split on any whitespace or punctuation that can't be part of an at mention or emoji pattern
-		return !(c == '.' || c == '-' || c == '_' || c == '@' || unicode.IsLetter(c) || unicode.IsNumber(c))
+		return !(c == ':' || c == '.' || c == '-' || c == '_' || c == '@' || unicode.IsLetter(c) || unicode.IsNumber(c))
 	}) {
 		isMention := false
 
+		// skip word with format ':word:' with an assumption that it is an emoji format only
+		if word[0] == ':' && word[len(word)-1] == ':' {
+			continue
+		}
+
 		if word == "@here" {
 			hereMentioned = true
 		}
@@ -837,10 +842,10 @@ func GetExplicitMentions(message string, keywords map[string][]string) (map[stri
 			continue
 		}
 
-		if strings.ContainsAny(word, ".-") {
+		if strings.ContainsAny(word, ".-:") {
 			// This word contains a character that may be the end of a sentence, so split further
 			splitWords := strings.FieldsFunc(word, func(c rune) bool {
-				return c == '.' || c == '-'
+				return c == '.' || c == '-' || c == ':'
 			})
 
 			for _, splitWord := range splitWords {

app/notification_test.go

@@ -200,6 +200,30 @@ func TestGetExplicitMentions(t *testing.T) {
 	if mentions, _, _, _, _ := GetExplicitMentions(message, keywords); len(mentions) != 1 || !mentions[id1] || mentions[id2] || mentions[id3] {
 		t.Fatal("should've only mentioned aaa")
 	}
+
+	message = ":smile:"
+	keywords = map[string][]string{"smile": {id1}, "smiley": {id2}, "smiley_cat": {id3}}
+	if mentions, _, _, _, _ := GetExplicitMentions(message, keywords); len(mentions) == 1 || mentions[id1] {
+		t.Fatal("should not mentioned smile")
+	}
+
+	message = "smile"
+	keywords = map[string][]string{"smile": {id1}, "smiley": {id2}, "smiley_cat": {id3}}
+	if mentions, _, _, _, _ := GetExplicitMentions(message, keywords); len(mentions) != 1 || !mentions[id1] || mentions[id2] || mentions[id3] {
+		t.Fatal("should've only mentioned smile")
+	}
+
+	message = ":smile"
+	keywords = map[string][]string{"smile": {id1}, "smiley": {id2}, "smiley_cat": {id3}}
+	if mentions, _, _, _, _ := GetExplicitMentions(message, keywords); len(mentions) != 1 || !mentions[id1] || mentions[id2] || mentions[id3] {
+		t.Fatal("should've only mentioned smile")
+	}
+
+	message = "smile:"
+	keywords = map[string][]string{"smile": {id1}, "smiley": {id2}, "smiley_cat": {id3}}
+	if mentions, _, _, _, _ := GetExplicitMentions(message, keywords); len(mentions) != 1 || !mentions[id1] || mentions[id2] || mentions[id3] {
+		t.Fatal("should've only mentioned smile")
+	}
 }
 
 func TestGetExplicitMentionsAtHere(t *testing.T) {
@@ -230,7 +254,7 @@ func TestGetExplicitMentionsAtHere(t *testing.T) {
 		"\\@here\\": true,
 		"|@here|":   true,
 		";@here;":   true,
-		":@here:":   true,
+		":@here:":   false, // This case shouldn't trigger a mention since it follows the format of reactions e.g. :word:
 		"'@here'":   true,
 		"\"@here\"": true,
 		",@here,":   true,