SlashCommandEducator should check length (#783)

Author: abhishekanuj26

application/src/main/java/org/togetherjava/tjbot/features/basic/SlashCommandEducator.java

@@ -19,6 +19,7 @@
  * then educates the user about using slash commands, such as {@code /foo} instead.
  */
 public final class SlashCommandEducator extends MessageReceiverAdapter {
+    private static final int MAX_COMMAND_LENGTH = 30;
     private static final String SLASH_COMMAND_POPUP_ADVICE_PATH = "slashCommandPopupAdvice.png";
     private static final Predicate<String> IS_MESSAGE_COMMAND = Pattern.compile("""
             [.!?] #Start of message command
@@ -33,7 +34,8 @@ public void onMessageReceived(MessageReceivedEvent event) {
         }
 
         String content = event.getMessage().getContentRaw();
-        if (IS_MESSAGE_COMMAND.test(content)) {
+
+        if (IS_MESSAGE_COMMAND.test(content) && content.length() < MAX_COMMAND_LENGTH) {
             sendAdvice(event.getMessage());
         }
     }

application/src/test/java/org/togetherjava/tjbot/features/basic/SlashCommandEducatorTest.java

@@ -65,6 +65,9 @@ private static Stream<String> provideMessageCommands() {
     }
 
     private static Stream<String> provideOtherMessages() {
-        return Stream.of("  a  ", "foo", "#foo", "/foo", "!!!", "?!?!?", "?", ".,-", "!f", "! foo");
+        return Stream.of("  a  ", "foo", "#foo", "/foo", "!!!", "?!?!?", "?", ".,-", "!f", "! foo",
+                "thisIsAWordWhichLengthIsMoreThanThirtyLetterSoItShouldNotReply",
+                ".isLetter and .isNumber are available");
+
     }
 }