Added tests for the failover

Signed-off-by: Aditya Arya <arya050411@gmail.com>

Author: Adityarya11

src/sdk/main/include/TransactionResponse.h

@@ -45,7 +45,7 @@ class TransactionResponse
   TransactionResponse(AccountId nodeId,
                       TransactionId transactionId,
                       std::vector<std::byte> hash,
-                      std::vector<AccountId> transactionNodeAccountIds);
+                      std::vector<AccountId> transactionNodeAccountIds = {});
 
   /**
    * Get a TransactionReceipt for this TransactionResponse's corresponding Transaction.

src/sdk/tests/unit/TransactionResponseUnitTests.cc

@@ -1,4 +1,8 @@
 // SPDX-License-Identifier: Apache-2.0
+#include "AccountId.h"
+#include "Client.h"
+#include "TransactionReceiptQuery.h"
+#include "TransactionRecordQuery.h"
 #include "TransactionResponse.h"
 
 #include <gtest/gtest.h>
@@ -29,3 +33,50 @@ TEST_F(TransactionResponseUnitTests, ContructTransactionResponse)
   EXPECT_EQ(transactionResponse.mTransactionId, transactionId);
   EXPECT_EQ(transactionResponse.mTransactionNodeAccountIds, nodeAccountIds);
 }
+
+//-----
+TEST_F(TransactionResponseUnitTests, GetReceiptQueryNullClientPinsToSubmittingNode)
+{
+  // Given
+  const AccountId submittingNode(0ULL, 0ULL, 3ULL);
+  const TransactionId txId = TransactionId::withValidStart(AccountId(1ULL), std::chrono::system_clock::now());
+  const TransactionResponse response(submittingNode, txId, {}, { submittingNode, AccountId(0ULL, 0ULL, 4ULL) });
+
+  // When / Then: no client → pinned to submitting node only
+  EXPECT_EQ(response.getReceiptQuery(nullptr).getNodeAccountIds(), (std::vector<AccountId>{ submittingNode }));
+}
+
+//-----
+TEST_F(TransactionResponseUnitTests, GetReceiptQueryFailoverBuildsNodeListFromTransactionNodes)
+{
+  // Given: transaction nodes 3, 5, 4 (unsorted); submitting node is 3
+  const AccountId submittingNode(0ULL, 0ULL, 3ULL);
+  const AccountId node4(0ULL, 0ULL, 4ULL);
+  const AccountId node5(0ULL, 0ULL, 5ULL);
+  const TransactionId txId = TransactionId::withValidStart(AccountId(1ULL), std::chrono::system_clock::now());
+  const TransactionResponse response(submittingNode, txId, {}, { submittingNode, node5, node4 });
+
+  Client client;
+  client.setAllowReceiptNodeFailover(true);
+
+  // When / Then: submitting node first, remaining sorted by account number ascending
+  const std::vector<AccountId> expected = { submittingNode, node4, node5 };
+  EXPECT_EQ(response.getReceiptQuery(&client).getNodeAccountIds(), expected);
+}
+
+//-----
+TEST_F(TransactionResponseUnitTests, SingleFlagGovernsReceiptAndRecordQueryNodeList)
+{
+  // Given
+  const AccountId submittingNode(0ULL, 0ULL, 3ULL);
+  const AccountId node4(0ULL, 0ULL, 4ULL);
+  const TransactionId txId = TransactionId::withValidStart(AccountId(1ULL), std::chrono::system_clock::now());
+  const TransactionResponse response(submittingNode, txId, {}, { submittingNode, node4 });
+
+  Client client;
+  client.setAllowReceiptNodeFailover(true);
+
+  // When / Then: same flag, same node list for both query types
+  EXPECT_EQ(response.getReceiptQuery(&client).getNodeAccountIds(),
+            response.getRecordQuery(&client).getNodeAccountIds());
+}