MM-10036 Ensured correct handling of capitalized special mentions (#8607)

app/notification.go

@@ -842,15 +842,15 @@ func GetExplicitMentions(message string, keywords map[string][]string) *Explicit
 	checkForMention := func(word string) bool {
 		isMention := false
 
-		if word == "@here" {
+		if strings.ToLower(word) == "@here" {
 			ret.HereMentioned = true
 		}
 
-		if word == "@channel" {
+		if strings.ToLower(word) == "@channel" {
 			ret.ChannelMentioned = true
 		}
 
-		if word == "@all" {
+		if strings.ToLower(word) == "@all" {
 			ret.AllMentioned = true
 		}
 

app/notification_test.go

@@ -186,6 +186,17 @@ func TestGetExplicitMentions(t *testing.T) {
 				ChannelMentioned: true,
 			},
 		},
+		"CapitalizedChannel": {
+			Message:  "this is an message for @cHaNNeL",
+			Keywords: map[string][]string{"@channel": {id1, id2}},
+			Expected: &ExplicitMentions{
+				MentionedUserIds: map[string]bool{
+					id1: true,
+					id2: true,
+				},
+				ChannelMentioned: true,
+			},
+		},
 		"All": {
 			Message:  "this is an message for @all",
 			Keywords: map[string][]string{"@all": {id1, id2}},
@@ -197,6 +208,17 @@ func TestGetExplicitMentions(t *testing.T) {
 				AllMentioned: true,
 			},
 		},
+		"CapitalizedAll": {
+			Message:  "this is an message for @ALL",
+			Keywords: map[string][]string{"@all": {id1, id2}},
+			Expected: &ExplicitMentions{
+				MentionedUserIds: map[string]bool{
+					id1: true,
+					id2: true,
+				},
+				AllMentioned: true,
+			},
+		},
 		"UserWithPeriod": {
 			Message:  "user.period doesn't complicate things at all by including periods in their username",
 			Keywords: map[string][]string{"user.period": {id1}, "user": {id2}},
@@ -439,6 +461,8 @@ func TestGetExplicitMentionsAtHere(t *testing.T) {
 		"?@here?":   true,
 		"`@here`":   false, // This case shouldn't mention since it's a code block
 		"~@here~":   true,
+		"@HERE":     true,
+		"@hERe":     true,
 	}
 
 	for message, shouldMention := range cases {