[fix][test] Improve the declare exchange test (#1150)

(cherry picked from commit 21fb671)

tests/src/test/java/io/streamnative/pulsar/handlers/amqp/rabbitmq/functional/ExchangeDeclareTest.java

@@ -26,7 +26,9 @@
 import java.io.IOException;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
+import org.awaitility.Awaitility;
 import org.testng.annotations.Test;
 
 /**
@@ -121,24 +123,47 @@ private void doTestExchangeDeclaredWithEnumerationEquivalent(Channel channel)
         for (BuiltinExchangeType exchangeType : BuiltinExchangeType.values()) {
             channel.exchangeDeclare(NAME, exchangeType);
             verifyEquivalent(NAME, exchangeType.getType(), false, false, null);
-            channel.exchangeDelete(NAME);
+            deleteExchangeWithRetry();
 
             channel.exchangeDeclare(NAME, exchangeType, false);
             verifyEquivalent(NAME, exchangeType.getType(), false, false, null);
-            channel.exchangeDelete(NAME);
+            deleteExchangeWithRetry();
 
             channel.exchangeDeclare(NAME, exchangeType, false, false, null);
             verifyEquivalent(NAME, exchangeType.getType(), false, false, null);
-            channel.exchangeDelete(NAME);
+            deleteExchangeWithRetry();
 
             channel.exchangeDeclare(NAME, exchangeType, false, false, false, null);
             verifyEquivalent(NAME, exchangeType.getType(), false, false, null);
-            channel.exchangeDelete(NAME);
+            deleteExchangeWithRetry();
 
             channel.exchangeDeclareNoWait(NAME, exchangeType, false,
                     false, false, null);
             // no check, this one is asynchronous
-            channel.exchangeDelete(NAME);
+            deleteExchangeWithRetry();
         }
     }
+
+    public void deleteExchangeWithRetry() throws IOException {
+        // the replicator cursor of exchange is created in async way,
+        // delete the exchange may fail due to non-empty directory error
+        //
+        // KeeperErrorCode = Directory not empty for
+        // /managed-ledgers/public/vhost1/persistent/__amqp_exchange__exchange_test
+        //
+        // - /managed-ledgers/public/vhost1/persistent/__amqp_exchange__exchange_test
+        // - /managed-ledgers/public/vhost1/persistent/__amqp_exchange__exchange_test/__amqp_replicator__exchange_test
+        Awaitility.await()
+                .atMost(5, TimeUnit.SECONDS)
+                .pollInterval(100, TimeUnit.MILLISECONDS)
+                .until(() -> {
+                    try {
+                        channel.exchangeDelete(NAME);
+                    } catch (Exception e) {
+                        return false;
+                    }
+                    return true;
+                });
+    }
+
 }