From daa1303b5a700ee66aee6209e411ad07496b37d5 Mon Sep 17 00:00:00 2001
From: Shawn Xie <35279399+shawnxie999@users.noreply.github.com>
Date: Fri, 17 Oct 2025 14:19:19 -0400
Subject: [PATCH] Update decryption test helper function (#5907)

---
 src/test/jtx/impl/mpt.cpp | 49 +++++++++++++++++++++++++--------------
 src/test/jtx/mpt.h        |  5 ++++
 2 files changed, 36 insertions(+), 18 deletions(-)

diff --git a/src/test/jtx/impl/mpt.cpp b/src/test/jtx/impl/mpt.cpp
index 069cdc0da7..fb2e9b4daa 100644
--- a/src/test/jtx/impl/mpt.cpp
+++ b/src/test/jtx/impl/mpt.cpp
@@ -625,15 +625,6 @@ MPTTester::convert(MPTConvert const& arg)
     auto const holderAmt = getBalance(*arg.account);
     auto const prevConfidentialOutstanding = getIssuanceConfidentialBalance();
 
-    auto getDecryptedBalance =
-        [&](auto const& account, EncryptedBalanceType balanceType) -> uint64_t {
-        auto maybeEncrypted = getEncryptedBalance(account, balanceType);
-        auto accountToDecrypt =
-            balanceType == ISSUER_ENCRYPTED_BALANCE ? issuer_ : account;
-        return maybeEncrypted ? decryptAmount(accountToDecrypt, *maybeEncrypted)
-                              : 0;
-    };
-
     uint64_t prevInboxBalance =
         getDecryptedBalance(*arg.account, HOLDER_ENCRYPTED_INBOX);
     uint64_t prevSpendingBalance =
@@ -651,27 +642,36 @@ MPTTester::convert(MPTConvert const& arg)
                 curConfidentialOutstanding;
         }));
 
+        uint64_t postInboxBalance =
+            getDecryptedBalance(*arg.account, HOLDER_ENCRYPTED_INBOX);
+        uint64_t postIssuerBalance =
+            getDecryptedBalance(*arg.account, ISSUER_ENCRYPTED_BALANCE);
+        uint64_t postSpendingBalance =
+            getDecryptedBalance(*arg.account, HOLDER_ENCRYPTED_SPENDING);
+
+        std::cout << "\n postIssuerBalance is " << postIssuerBalance << '\n';
+        std::cout << "\n postInboxBalance is " << postInboxBalance << '\n';
+
         // spending balance should not change
         env_.require(requireAny([&]() -> bool {
-            uint64_t postSpendingBalance =
-                getDecryptedBalance(*arg.account, HOLDER_ENCRYPTED_SPENDING);
             return postSpendingBalance == prevSpendingBalance;
         }));
 
+        // issuer's encrypted balance is updated correctly
         env_.require(requireAny([&]() -> bool {
-            uint64_t postIssuerBalance =
-                getDecryptedBalance(*arg.account, ISSUER_ENCRYPTED_BALANCE);
-            std::cout << "\n postIssuerBalance is " << postIssuerBalance
-                      << '\n';
             return prevIssuerBalance + *arg.amt == postIssuerBalance;
         }));
 
+        // holder's inbox balance is updated correctly
         env_.require(requireAny([&]() -> bool {
-            uint64_t postInboxBalance =
-                getDecryptedBalance(*arg.account, HOLDER_ENCRYPTED_INBOX);
-            std::cout << "\n postInboxBalance is " << postInboxBalance << '\n';
             return prevInboxBalance + *arg.amt == postInboxBalance;
         }));
+
+        // sum of holder's inbox and spending balance should equal to issuer's
+        // encrypted balance
+        env_.require(requireAny([&]() -> bool {
+            return postInboxBalance + postSpendingBalance == postIssuerBalance;
+        }));
     }
 }
 
@@ -741,6 +741,19 @@ MPTTester::decryptAmount(Account const& account, Buffer const& amt) const
     return decryptedAmt;
 }
 
+uint64_t
+MPTTester::getDecryptedBalance(
+    Account const& account,
+    EncryptedBalanceType balanceType) const
+
+{
+    auto maybeEncrypted = getEncryptedBalance(account, balanceType);
+    auto accountToDecrypt =
+        balanceType == ISSUER_ENCRYPTED_BALANCE ? issuer_ : account;
+    return maybeEncrypted ? decryptAmount(accountToDecrypt, *maybeEncrypted)
+                          : 0;
+};
+
 }  // namespace jtx
 }  // namespace test
 }  // namespace ripple
diff --git a/src/test/jtx/mpt.h b/src/test/jtx/mpt.h
index e031e661cb..273d02a9ed 100644
--- a/src/test/jtx/mpt.h
+++ b/src/test/jtx/mpt.h
@@ -295,6 +295,11 @@ public:
     uint64_t
     decryptAmount(Account const& account, Buffer const& amt) const;
 
+    uint64_t
+    getDecryptedBalance(
+        Account const& account,
+        EncryptedBalanceType balanceType) const;
+
 private:
     using SLEP = std::shared_ptr<SLE const>;
     bool