rpc: deprecate fee fields from mempool entries

Unless `-deprecatedrpc=fees` is passed, top level
fee fields are no longer returned for mempool entries.

Add instructions to field help on how to access
deprecated fields, update help text for readability,
and include units. This is important to help
avoid any confusion as users move from deprecated
fields to the fee fields object (credit: jonatack).

This affects `getmempoolentry`, `getrawmempool`,
`getmempoolancestors`, and `getmempooldescendants`

Modify `test/functional/mempool_packages.py` and
`test/functional/rpc_fundrawtransaction.py` tests
to no longer use deprecated fields.

Co-authored-by: jonatack <jon@atack.com>

1 files changed, 20 insertions, 13 deletions

diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index aa7a55e7a9..2c7f1a70ae 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -462,23 +462,23 @@ static RPCHelpMan getdifficulty()
 static std::vector<RPCResult> MempoolEntryDescription() { return {
     RPCResult{RPCResult::Type::NUM, "vsize", "virtual transaction size as defined in BIP 141. This is different from actual serialized size for witness transactions as witness data is discounted."},
     RPCResult{RPCResult::Type::NUM, "weight", "transaction weight as defined in BIP 141."},
-    RPCResult{RPCResult::Type::STR_AMOUNT, "fee", "transaction fee in " + CURRENCY_UNIT + " (DEPRECATED)"},
-    RPCResult{RPCResult::Type::STR_AMOUNT, "modifiedfee", "transaction fee with fee deltas used for mining priority (DEPRECATED)"},
+    RPCResult{RPCResult::Type::STR_AMOUNT, "fee", "transaction fee, denominated in " + CURRENCY_UNIT + " (DEPRECATED, returned only if config option -deprecatedrpc=fees is passed)"},
+    RPCResult{RPCResult::Type::STR_AMOUNT, "modifiedfee", "transaction fee with fee deltas used for mining priority, denominated in " + CURRENCY_UNIT + " (DEPRECATED, returned only if config option -deprecatedrpc=fees is passed)"},
     RPCResult{RPCResult::Type::NUM_TIME, "time", "local time transaction entered pool in seconds since 1 Jan 1970 GMT"},
     RPCResult{RPCResult::Type::NUM, "height", "block height when transaction entered pool"},
     RPCResult{RPCResult::Type::NUM, "descendantcount", "number of in-mempool descendant transactions (including this one)"},
     RPCResult{RPCResult::Type::NUM, "descendantsize", "virtual transaction size of in-mempool descendants (including this one)"},
-    RPCResult{RPCResult::Type::STR_AMOUNT, "descendantfees", "modified fees (see above) of in-mempool descendants (including this one) (DEPRECATED)"},
+    RPCResult{RPCResult::Type::STR_AMOUNT, "descendantfees", "transaction fees of in-mempool descendants (including this one) with fee deltas used for mining priority, denominated in " + CURRENCY_ATOM + "s (DEPRECATED, returned only if config option -deprecatedrpc=fees is passed)"},
     RPCResult{RPCResult::Type::NUM, "ancestorcount", "number of in-mempool ancestor transactions (including this one)"},
     RPCResult{RPCResult::Type::NUM, "ancestorsize", "virtual transaction size of in-mempool ancestors (including this one)"},
-    RPCResult{RPCResult::Type::STR_AMOUNT, "ancestorfees", "modified fees (see above) of in-mempool ancestors (including this one) (DEPRECATED)"},
+    RPCResult{RPCResult::Type::STR_AMOUNT, "ancestorfees", "transaction fees of in-mempool ancestors (including this one) with fee deltas used for mining priority, denominated in " + CURRENCY_ATOM + "s (DEPRECATED, returned only if config option -deprecatedrpc=fees is passed)"},
     RPCResult{RPCResult::Type::STR_HEX, "wtxid", "hash of serialized transaction, including witness data"},
     RPCResult{RPCResult::Type::OBJ, "fees", "",
         {
-            RPCResult{RPCResult::Type::STR_AMOUNT, "base", "transaction fee in " + CURRENCY_UNIT},
-            RPCResult{RPCResult::Type::STR_AMOUNT, "modified", "transaction fee with fee deltas used for mining priority in " + CURRENCY_UNIT},
-            RPCResult{RPCResult::Type::STR_AMOUNT, "ancestor", "modified fees (see above) of in-mempool ancestors (including this one) in " + CURRENCY_UNIT},
-            RPCResult{RPCResult::Type::STR_AMOUNT, "descendant", "modified fees (see above) of in-mempool descendants (including this one) in " + CURRENCY_UNIT},
+            RPCResult{RPCResult::Type::STR_AMOUNT, "base", "transaction fee, denominated in " + CURRENCY_UNIT},
+            RPCResult{RPCResult::Type::STR_AMOUNT, "modified", "transaction fee with fee deltas used for mining priority, denominated in " + CURRENCY_UNIT},
+            RPCResult{RPCResult::Type::STR_AMOUNT, "ancestor", "transaction fees of in-mempool ancestors (including this one) with fee deltas used for mining priority, denominated in " + CURRENCY_UNIT},
+            RPCResult{RPCResult::Type::STR_AMOUNT, "descendant", "transaction fees of in-mempool descendants (including this one) with fee deltas used for mining priority, denominated in " + CURRENCY_UNIT},
         }},
     RPCResult{RPCResult::Type::ARR, "depends", "unconfirmed transactions used as inputs for this transaction",
         {RPCResult{RPCResult::Type::STR_HEX, "transactionid", "parent transaction id"}}},
@@ -498,19 +498,26 @@ static void entryToJSON(const CTxMemPool& pool, UniValue& info, const CTxMemPool
     fees.pushKV("ancestor", ValueFromAmount(e.GetModFeesWithAncestors()));
     fees.pushKV("descendant", ValueFromAmount(e.GetModFeesWithDescendants()));
     info.pushKV("fees", fees);
-
     info.pushKV("vsize", (int)e.GetTxSize());
     info.pushKV("weight", (int)e.GetTxWeight());
-    info.pushKV("fee", ValueFromAmount(e.GetFee()));
-    info.pushKV("modifiedfee", ValueFromAmount(e.GetModifiedFee()));
+    // TODO: top-level fee fields are deprecated. deprecated_fee_fields_enabled blocks should be removed in v24
+    const bool deprecated_fee_fields_enabled{IsDeprecatedRPCEnabled("fees")};
+    if (deprecated_fee_fields_enabled) {
+        info.pushKV("fee", ValueFromAmount(e.GetFee()));
+        info.pushKV("modifiedfee", ValueFromAmount(e.GetModifiedFee()));
+    }
     info.pushKV("time", count_seconds(e.GetTime()));
     info.pushKV("height", (int)e.GetHeight());
     info.pushKV("descendantcount", e.GetCountWithDescendants());
     info.pushKV("descendantsize", e.GetSizeWithDescendants());
-    info.pushKV("descendantfees", e.GetModFeesWithDescendants());
+    if (deprecated_fee_fields_enabled) {
+        info.pushKV("descendantfees", e.GetModFeesWithDescendants());
+    }
     info.pushKV("ancestorcount", e.GetCountWithAncestors());
     info.pushKV("ancestorsize", e.GetSizeWithAncestors());
-    info.pushKV("ancestorfees", e.GetModFeesWithAncestors());
+    if (deprecated_fee_fields_enabled) {
+        info.pushKV("ancestorfees", e.GetModFeesWithAncestors());
+    }
     info.pushKV("wtxid", pool.vTxHashes[e.vTxHashesIdx].first.ToString());
     const CTransaction& tx = e.GetTx();
     std::set<std::string> setDepends;