fix(codegen): fix multiple comment being not properly stiched together

Author: sruehl

code-generation/protocol-base-mspec/pom.xml

@@ -87,6 +87,10 @@
       <groupId>commons-io</groupId>
       <artifactId>commons-io</artifactId>
     </dependency>
+    <dependency>
+      <groupId>org.apache.commons</groupId>
+      <artifactId>commons-lang3</artifactId>
+    </dependency>
     <dependency>
       <groupId>org.antlr</groupId>
       <artifactId>antlr4-runtime</artifactId>

code-generation/protocol-base-mspec/src/main/java/org/apache/plc4x/plugins/codegenerator/language/mspec/parser/MessageFormatListener.java

@@ -23,6 +23,7 @@
 import org.antlr.v4.runtime.RuleContext;
 import org.antlr.v4.runtime.Token;
 import org.apache.commons.io.IOUtils;
+import org.apache.commons.lang3.StringUtils;
 import org.apache.plc4x.plugins.codegenerator.language.mspec.LazyTypeDefinitionConsumer;
 import org.apache.plc4x.plugins.codegenerator.language.mspec.MSpecBaseListener;
 import org.apache.plc4x.plugins.codegenerator.language.mspec.MSpecLexer;
@@ -120,7 +121,7 @@ private String consumePendingComment(ParserRuleContext ctx) {
 
         var defLine = startToken.getLine();
         if (!frontComments.isEmpty() && frontComments.getFirst().getLine() == defLine - 1) {
-            frontComments.reversed().forEach(token -> comment.append(token.getText()));
+            frontComments.reversed().stream().map(Token::getText).forEach(tokenText -> comment.append(tokenText).append('\n'));
         }
 
         if (eolComment != null && eolComment.getLine() == defLine) {
@@ -130,7 +131,12 @@ private String consumePendingComment(ParserRuleContext ctx) {
         if (comment.isEmpty()) {
             return null;
         }
-        return comment.toString();
+        String commentString = comment.toString();
+        if (StringUtils.isBlank(commentString)) {
+            return null;
+        }
+        commentString = StringUtils.stripEnd(commentString, "\n");
+        return commentString;
     }
 
     @Override