Merge #20573: wallet, bugfix: allow send with string fee_rate amounts

6fa72ceb8021c3b5aea62f6cfe92665c29212923 test: add coverage for passing fee rate as a string (Jon Atack)
ce207d6b93d35bc02fcd2dd28f1fd95869261d43 wallet, bugfix: allow send to take string fee rate values (Jon Atack)

Pull request description:

  RPC send currently only accepts fee rates as numbers, which is a user-facing bug. It should accept fee rates as an amount, e.g. a string or a number, as documented in its help and like sendtoaddress, sendmany, fundrawtransaction, walletcreatefundedpsbt, and bumpfee. Provide a fix and regression test coverage.

ACKs for top commit:
  MarcoFalke:
    review ACK 6fa72ceb8021c3b5aea62f6cfe92665c29212923
  achow101:
    Code review ACK 6fa72ceb8021c3b5aea62f6cfe92665c29212923
  promag:
    Code review ACK 6fa72ceb8021c3b5aea62f6cfe92665c29212923.

Tree-SHA512: 735f9269cb1b81953764b5283449c0b154bd62de034225be5bcedc515c84faf767fe8fe0741008679fe412922c847b00d116cb11aab775236b779c847ba87167

6 files changed, 35 insertions, 10 deletions

diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index 7ea6a214b2..e580c9a8ea 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -4089,7 +4089,7 @@ static RPCHelpMan send()
                 UniValueType(), // outputs (ARR or OBJ, checked later)
                 UniValue::VNUM, // conf_target
                 UniValue::VSTR, // estimate_mode
-                UniValue::VNUM, // fee_rate
+                UniValueType(), // fee_rate, will be checked by AmountFromValue() in SetFeeEstimateMode()
                 UniValue::VOBJ, // options
                 }, true
             );
diff --git a/test/functional/rpc_fundrawtransaction.py b/test/functional/rpc_fundrawtransaction.py
index 8ee0ecab0a..569471dc87 100755
--- a/test/functional/rpc_fundrawtransaction.py
+++ b/test/functional/rpc_fundrawtransaction.py
@@ -717,10 +717,10 @@ class RawTransactionsTest(BitcoinTestFramework):
 
         result = node.fundrawtransaction(rawtx)  # uses self.min_relay_tx_fee (set by settxfee)
         btc_kvb_to_sat_vb = 100000  # (1e5)
-        result1 = node.fundrawtransaction(rawtx, {"fee_rate": 2 * btc_kvb_to_sat_vb * self.min_relay_tx_fee})
+        result1 = node.fundrawtransaction(rawtx, {"fee_rate": str(2 * btc_kvb_to_sat_vb * self.min_relay_tx_fee)})
         result2 = node.fundrawtransaction(rawtx, {"feeRate": 2 * self.min_relay_tx_fee})
         result3 = node.fundrawtransaction(rawtx, {"fee_rate": 10 * btc_kvb_to_sat_vb * self.min_relay_tx_fee})
-        result4 = node.fundrawtransaction(rawtx, {"feeRate": 10 * self.min_relay_tx_fee})
+        result4 = node.fundrawtransaction(rawtx, {"feeRate": str(10 * self.min_relay_tx_fee)})
         # Test that funding non-standard "zero-fee" transactions is valid.
         result5 = self.nodes[3].fundrawtransaction(rawtx, {"fee_rate": 0})
         result6 = self.nodes[3].fundrawtransaction(rawtx, {"feeRate": 0})
diff --git a/test/functional/rpc_psbt.py b/test/functional/rpc_psbt.py
index 5840801b00..b364077a9a 100755
--- a/test/functional/rpc_psbt.py
+++ b/test/functional/rpc_psbt.py
@@ -190,11 +190,11 @@ class PSBTTest(BitcoinTestFramework):
         self.log.info("Test walletcreatefundedpsbt fee rate of 10000 sat/vB and 0.1 BTC/kvB produces a total fee at or slightly below -maxtxfee (~0.05290000)")
         res1 = self.nodes[1].walletcreatefundedpsbt(inputs, outputs, 0, {"fee_rate": 10000, "add_inputs": True})
         assert_approx(res1["fee"], 0.055, 0.005)
-        res2 = self.nodes[1].walletcreatefundedpsbt(inputs, outputs, 0, {"feeRate": 0.1, "add_inputs": True})
+        res2 = self.nodes[1].walletcreatefundedpsbt(inputs, outputs, 0, {"feeRate": "0.1", "add_inputs": True})
         assert_approx(res2["fee"], 0.055, 0.005)
 
         self.log.info("Test min fee rate checks with walletcreatefundedpsbt are bypassed, e.g. a fee_rate under 1 sat/vB is allowed")
-        res3 = self.nodes[1].walletcreatefundedpsbt(inputs, outputs, 0, {"fee_rate": 0.99999999, "add_inputs": True})
+        res3 = self.nodes[1].walletcreatefundedpsbt(inputs, outputs, 0, {"fee_rate": "0.99999999", "add_inputs": True})
         assert_approx(res3["fee"], 0.00000381, 0.0000001)
         res4 = self.nodes[1].walletcreatefundedpsbt(inputs, outputs, 0, {"feeRate": 0.00000999, "add_inputs": True})
         assert_approx(res4["fee"], 0.00000381, 0.0000001)
diff --git a/test/functional/wallet_basic.py b/test/functional/wallet_basic.py
index ac4a6e4948..3cbddaf6da 100755
--- a/test/functional/wallet_basic.py
+++ b/test/functional/wallet_basic.py
@@ -235,7 +235,8 @@ class WalletTest(BitcoinTestFramework):
         fee_rate_btc_kvb = fee_rate_sat_vb * 1e3 / 1e8
         explicit_fee_rate_btc_kvb = Decimal(fee_rate_btc_kvb) / 1000
 
-        txid = self.nodes[2].sendmany(amounts={address: 10}, fee_rate=fee_rate_sat_vb)
+        # Test passing fee_rate as a string
+        txid = self.nodes[2].sendmany(amounts={address: 10}, fee_rate=str(fee_rate_sat_vb))
         self.nodes[2].generate(1)
         self.sync_all(self.nodes[0:3])
         balance = self.nodes[2].getbalance()
@@ -244,6 +245,17 @@ class WalletTest(BitcoinTestFramework):
         node_0_bal += Decimal('10')
         assert_equal(self.nodes[0].getbalance(), node_0_bal)
 
+        # Test passing fee_rate as an integer
+        amount = Decimal("0.0001")
+        txid = self.nodes[2].sendmany(amounts={address: amount}, fee_rate=fee_rate_sat_vb)
+        self.nodes[2].generate(1)
+        self.sync_all(self.nodes[0:3])
+        balance = self.nodes[2].getbalance()
+        node_2_bal = self.check_fee_amount(balance, node_2_bal - amount, explicit_fee_rate_btc_kvb, self.get_vsize(self.nodes[2].gettransaction(txid)['hex']))
+        assert_equal(balance, node_2_bal)
+        node_0_bal += amount
+        assert_equal(self.nodes[0].getbalance(), node_0_bal)
+
         for key in ["totalFee", "feeRate"]:
             assert_raises_rpc_error(-8, "Unknown named parameter key", self.nodes[2].sendtoaddress, address=address, amount=1, fee_rate=1, key=1)
 
@@ -405,7 +417,7 @@ class WalletTest(BitcoinTestFramework):
             amount = 3
             fee_rate_sat_vb = 2
             fee_rate_btc_kvb = fee_rate_sat_vb * 1e3 / 1e8
-
+            # Test passing fee_rate as an integer
             txid = self.nodes[2].sendtoaddress(address=address, amount=amount, fee_rate=fee_rate_sat_vb)
             tx_size = self.get_vsize(self.nodes[2].gettransaction(txid)['hex'])
             self.nodes[0].generate(1)
@@ -414,6 +426,19 @@ class WalletTest(BitcoinTestFramework):
             fee = prebalance - postbalance - Decimal(amount)
             assert_fee_amount(fee, tx_size, Decimal(fee_rate_btc_kvb))
 
+            prebalance = self.nodes[2].getbalance()
+            amount = Decimal("0.001")
+            fee_rate_sat_vb = 1.23
+            fee_rate_btc_kvb = fee_rate_sat_vb * 1e3 / 1e8
+            # Test passing fee_rate as a string
+            txid = self.nodes[2].sendtoaddress(address=address, amount=amount, fee_rate=str(fee_rate_sat_vb))
+            tx_size = self.get_vsize(self.nodes[2].gettransaction(txid)['hex'])
+            self.nodes[0].generate(1)
+            self.sync_all(self.nodes[0:3])
+            postbalance = self.nodes[2].getbalance()
+            fee = prebalance - postbalance - amount
+            assert_fee_amount(fee, tx_size, Decimal(fee_rate_btc_kvb))
+
             for key in ["totalFee", "feeRate"]:
                 assert_raises_rpc_error(-8, "Unknown named parameter key", self.nodes[2].sendtoaddress, address=address, amount=1, fee_rate=1, key=1)
 
diff --git a/test/functional/wallet_bumpfee.py b/test/functional/wallet_bumpfee.py
index 99c9737258..c8c1f2e374 100755
--- a/test/functional/wallet_bumpfee.py
+++ b/test/functional/wallet_bumpfee.py
@@ -149,7 +149,7 @@ def test_simple_bumpfee_succeeds(self, mode, rbf_node, peer_node, dest_address):
     self.sync_mempools((rbf_node, peer_node))
     assert rbfid in rbf_node.getrawmempool() and rbfid in peer_node.getrawmempool()
     if mode == "fee_rate":
-        bumped_psbt = rbf_node.psbtbumpfee(rbfid, {"fee_rate": NORMAL})
+        bumped_psbt = rbf_node.psbtbumpfee(rbfid, {"fee_rate": str(NORMAL)})
         bumped_tx = rbf_node.bumpfee(rbfid, {"fee_rate": NORMAL})
     else:
         bumped_psbt = rbf_node.psbtbumpfee(rbfid)
diff --git a/test/functional/wallet_send.py b/test/functional/wallet_send.py
index 192e9065e6..9835c5a2af 100755
--- a/test/functional/wallet_send.py
+++ b/test/functional/wallet_send.py
@@ -256,8 +256,8 @@ class WalletSendTest(BitcoinTestFramework):
         assert res["complete"]
 
         self.log.info("Test setting explicit fee rate")
-        res1 = self.test_send(from_wallet=w0, to_wallet=w1, amount=1, arg_fee_rate=1, add_to_wallet=False)
-        res2 = self.test_send(from_wallet=w0, to_wallet=w1, amount=1, fee_rate=1, add_to_wallet=False)
+        res1 = self.test_send(from_wallet=w0, to_wallet=w1, amount=1, arg_fee_rate="1", add_to_wallet=False)
+        res2 = self.test_send(from_wallet=w0, to_wallet=w1, amount=1, fee_rate="1", add_to_wallet=False)
         assert_equal(self.nodes[1].decodepsbt(res1["psbt"])["fee"], self.nodes[1].decodepsbt(res2["psbt"])["fee"])
 
         res = self.test_send(from_wallet=w0, to_wallet=w1, amount=1, fee_rate=7, add_to_wallet=False)