[agents] TextNormalizer: remove repeated sequences of space + new line

langstream-agents/langstream-agents-text-processing/src/main/java/ai/langstream/agents/text/TextNormaliserAgent.java

@@ -59,6 +59,7 @@ static String trimSpaces(String stream) {
         return stream.replaceAll("\t+", " ") // convert tabs to spaces
                 .replaceAll(" +", " ") // remove multiple spaces
                 .replaceAll("\n\n\n", "\n\n") // remove repeated newlines (3 or more)
+                .replaceAll("( \n)+", " \n") // remove repeated sequences of space + newlines
                 .trim();
     }
 }

langstream-agents/langstream-agents-text-processing/src/test/java/ai/langstream/agents/text/TextNormaliserAgentTest.java

@@ -23,13 +23,16 @@ class TextNormaliserAgentTest {
 
     @Test
     void testTrimSpaces() {
-        String text = "  some text with \t \tspaces \n\n\n this is a new line";
+        String text = "  some text with \t \tspaces \n\n\n this is a new line. \n \n \n     \n then two new lines. \n\n end";
         String result = TextNormaliserAgent.trimSpaces(text);
         assertEquals(
                 """
-            some text with spaces\s
-
-             this is a new line""",
+                        some text with spaces\s
+                                           
+                         this is a new line.\s
+                         then two new lines.\s
+                         
+                         end""",
                 result);
     }
 }