[improve][test] Added message properties tests for batch and non-batc…

…h messages (apache#23473)

pulsar-broker/src/test/java/org/apache/pulsar/broker/admin/PersistentTopicsTest.java

@@ -1905,4 +1905,76 @@ public void testUpdatePropertiesOnNonDurableSub() throws Exception {
         assertEquals(cursor.getCursorProperties().size(), 1);
         assertEquals(cursor.getCursorProperties().get("foo"), "bar");
     }
+
+    @Test
+    public void testPeekMessageWithProperties() throws Exception {
+        String topicName = "persistent://" + testTenant + "/" + testNamespaceLocal + "/testPeekMessageWithProperties";
+        admin.topics().createNonPartitionedTopic(topicName);
+
+        // Test non-batch messages
+        @Cleanup
+        Producer<String> nonBatchProducer = pulsarClient.newProducer(Schema.STRING)
+                .topic(topicName)
+                .enableBatching(false)
+                .create();
+
+        Map<String, String> props1 = new HashMap<>();
+        props1.put("key1", "value1");
+        props1.put("KEY2", "VALUE2");
+        props1.put("KeY3", "VaLuE3");
+
+        nonBatchProducer.newMessage()
+                .properties(props1)
+                .value("non-batch-message")
+                .send();
+
+        Message<byte[]> peekedMessage = admin.topics().peekMessages(topicName, "sub-peek", 1).get(0);
+        assertEquals(new String(peekedMessage.getData()), "non-batch-message");
+        assertEquals(peekedMessage.getProperties().size(), 3);
+        assertEquals(peekedMessage.getProperties().get("key1"), "value1");
+        assertEquals(peekedMessage.getProperties().get("KEY2"), "VALUE2");
+        assertEquals(peekedMessage.getProperties().get("KeY3"), "VaLuE3");
+
+        admin.topics().truncate(topicName);
+
+        // Test batch messages
+        @Cleanup
+        Producer<String> batchProducer = pulsarClient.newProducer(Schema.STRING)
+                .topic(topicName)
+                .enableBatching(true)
+                .batchingMaxPublishDelay(1, TimeUnit.SECONDS)
+                .batchingMaxMessages(2)
+                .create();
+
+        Map<String, String> props2 = new HashMap<>();
+        props2.put("batch-key1", "batch-value1");
+        props2.put("BATCH-KEY2", "BATCH-VALUE2");
+        props2.put("BaTcH-kEy3", "BaTcH-vAlUe3");
+
+        batchProducer.newMessage()
+                .properties(props2)
+                .value("batch-message-1")
+                .sendAsync();
+
+        batchProducer.newMessage()
+                .properties(props2)
+                .value("batch-message-2")
+                .send();
+
+        List<Message<byte[]>> peekedMessages = admin.topics().peekMessages(topicName, "sub-peek", 2);
+        assertEquals(peekedMessages.size(), 2);
+
+        for (int i = 0; i < 2; i++) {
+            Message<byte[]> batchMessage = peekedMessages.get(i);
+            assertEquals(new String(batchMessage.getData()), "batch-message-" + (i + 1));
+            assertEquals(batchMessage.getProperties().size(),
+                    3 + 2 // 3 properties from the message + 2 properties from the batch
+            );
+            assertEquals(batchMessage.getProperties().get("X-Pulsar-num-batch-message"), "2");
+            assertNotNull(batchMessage.getProperties().get("X-Pulsar-batch-size"));
+            assertEquals(batchMessage.getProperties().get("batch-key1"), "batch-value1");
+            assertEquals(batchMessage.getProperties().get("BATCH-KEY2"), "BATCH-VALUE2");
+            assertEquals(batchMessage.getProperties().get("BaTcH-kEy3"), "BaTcH-vAlUe3");
+        }
+    }
 }