From e72bbf4d9fb4157cc0387c7f11cda2e56b3126f4 Mon Sep 17 00:00:00 2001
From: tequ <git@tequ.dev>
Date: Thu, 11 Sep 2025 23:17:06 +0900
Subject: [PATCH] Add additional metadata to simulate response (#5754)

---
 src/test/rpc/Simulate_test.cpp      | 104 ++++++++++++++++++++++++++++
 src/xrpld/rpc/handlers/Simulate.cpp |  14 ++++
 2 files changed, 118 insertions(+)

diff --git a/src/test/rpc/Simulate_test.cpp b/src/test/rpc/Simulate_test.cpp
index d2874988a..b4e2c0518 100644
--- a/src/test/rpc/Simulate_test.cpp
+++ b/src/test/rpc/Simulate_test.cpp
@@ -136,6 +136,32 @@ class Simulate_test : public beast::unit_test::suite
             std::to_string(env.current()->txCount()));
     }
 
+    void
+    testTxJsonMetadataField(
+        jtx::Env& env,
+        Json::Value const& tx,
+        std::function<void(
+            Json::Value const&,
+            Json::Value const&,
+            Json::Value const&)> const& validate,
+        Json::Value const& expectedMetadataKey,
+        bool testSerialized = true)
+    {
+        env.close();
+
+        Json::Value params;
+        params[jss::tx_json] = tx;
+        validate(
+            env.rpc("json", "simulate", to_string(params)),
+            tx,
+            expectedMetadataKey);
+        validate(env.rpc("simulate", to_string(tx)), tx, expectedMetadataKey);
+
+        BEAST_EXPECTS(
+            env.current()->txCount() == 0,
+            std::to_string(env.current()->txCount()));
+    }
+
     Json::Value
     getJsonMetadata(Json::Value txResult) const
     {
@@ -1191,6 +1217,83 @@ class Simulate_test : public beast::unit_test::suite
         }
     }
 
+    void
+    testSuccessfulTransactionAdditionalMetadata()
+    {
+        testcase("Successful transaction with additional metadata");
+
+        using namespace jtx;
+        Env env{*this, envconfig([&](std::unique_ptr<Config> cfg) {
+                    cfg->NETWORK_ID = 1025;
+                    return cfg;
+                })};
+
+        Account const alice("alice");
+
+        env.fund(XRP(10000), alice);
+        env.close();
+
+        {
+            auto validateOutput = [&](Json::Value const& resp,
+                                      Json::Value const& tx,
+                                      Json::Value const& expectedMetadataKey) {
+                auto result = resp[jss::result];
+
+                BEAST_EXPECT(result[jss::engine_result] == "tesSUCCESS");
+                BEAST_EXPECT(result[jss::engine_result_code] == 0);
+                BEAST_EXPECT(
+                    result[jss::engine_result_message] ==
+                    "The simulated transaction would have been applied.");
+
+                if (BEAST_EXPECT(
+                        result.isMember(jss::meta) ||
+                        result.isMember(jss::meta_blob)))
+                {
+                    Json::Value const metadata = getJsonMetadata(result);
+
+                    BEAST_EXPECT(metadata[sfTransactionIndex.jsonName] == 0);
+                    BEAST_EXPECT(
+                        metadata[sfTransactionResult.jsonName] == "tesSUCCESS");
+                    BEAST_EXPECT(
+                        metadata.isMember(expectedMetadataKey.asString()));
+                }
+            };
+
+            {
+                Json::Value tx;
+                tx[jss::Account] = env.master.human();
+                tx[jss::TransactionType] = jss::Payment;
+                tx[sfDestination] = alice.human();
+                tx[sfAmount] = "100";
+
+                // test delivered amount
+                testTxJsonMetadataField(
+                    env, tx, validateOutput, jss::delivered_amount);
+            }
+
+            {
+                Json::Value tx;
+                tx[jss::Account] = env.master.human();
+                tx[jss::TransactionType] = jss::NFTokenMint;
+                tx[sfNFTokenTaxon] = 1;
+
+                // test nft synthetic
+                testTxJsonMetadataField(
+                    env, tx, validateOutput, jss::nftoken_id);
+            }
+
+            {
+                Json::Value tx;
+                tx[jss::Account] = env.master.human();
+                tx[jss::TransactionType] = jss::MPTokenIssuanceCreate;
+
+                // test mpt issuance id
+                testTxJsonMetadataField(
+                    env, tx, validateOutput, jss::mpt_issuance_id);
+            }
+        }
+    }
+
     void
     testHook()
     {
@@ -1311,6 +1414,7 @@ public:
         testMultisignedBadPubKey();
         testDeleteExpiredCredentials();
         testSuccessfulTransactionNetworkID();
+        testSuccessfulTransactionAdditionalMetadata();
         testHook();
     }
 };
diff --git a/src/xrpld/rpc/handlers/Simulate.cpp b/src/xrpld/rpc/handlers/Simulate.cpp
index 3c175883c..092b0b456 100644
--- a/src/xrpld/rpc/handlers/Simulate.cpp
+++ b/src/xrpld/rpc/handlers/Simulate.cpp
@@ -24,10 +24,13 @@
 #include <xrpld/app/misc/TxQ.h>
 #include <xrpld/app/tx/apply.h>
 #include <xrpld/rpc/Context.h>
+#include <xrpld/rpc/DeliveredAmount.h>
 #include <xrpld/rpc/GRPCHandlers.h>
+#include <xrpld/rpc/MPTokenIssuanceID.h>
 #include <xrpld/rpc/detail/TransactionSign.h>
 
 #include <xrpl/protocol/ErrorCodes.h>
+#include <xrpl/protocol/NFTSyntheticSerializer.h>
 #include <xrpl/protocol/RPCErr.h>
 #include <xrpl/protocol/STParsedJSON.h>
 #include <xrpl/resource/Fees.h>
@@ -272,6 +275,17 @@ simulateTxn(RPC::JsonContext& context, std::shared_ptr<Transaction> transaction)
         else
         {
             jvResult[jss::meta] = result.metadata->getJson(JsonOptions::none);
+            RPC::insertDeliveredAmount(
+                jvResult[jss::meta],
+                view,
+                transaction->getSTransaction(),
+                *result.metadata);
+            RPC::insertNFTSyntheticInJson(
+                jvResult, transaction->getSTransaction(), *result.metadata);
+            RPC::insertMPTokenIssuanceID(
+                jvResult[jss::meta],
+                transaction->getSTransaction(),
+                *result.metadata);
         }
     }