Merge #20220: wallet, rpc: explicit fee rate follow-ups/fixes for 0.21

0be29000c0 rpc: update conf_target helps for correctness/consistency (Jon Atack)
778b9be406 wallet, rpc: fix send subtract_fee_from_outputs help (Jon Atack)
603c005083 wallet: add rpc send explicit fee rate coverage (Jon Atack)
dd341e602d wallet: add sendtoaddress/sendmany explicit fee rate coverage (Jon Atack)
44e7bfa603 wallet: add walletcreatefundedpsbt explicit fee rate coverage (Jon Atack)
6e1ea4273e test: refactor for walletcreatefundedpsbt fee rate coverage (Jon Atack)
3ac7b0c6f1 wallet: fundrawtx fee rate coverage, fixup ParseConfirmTarget() (Jon Atack)
2d8eba8f84 wallet: combine redundant bumpfee invalid params and args tests (Jon Atack)
1697a40b6f wallet: improve bumpfee error/help, add explicit fee rate coverage (Jon Atack)
fc5721723d wallet: fix SetFeeEstimateMode() error message (Jon Atack)
052427eef1 wallet, bugfix: fix bumpfee with explicit fee rate modes (Jon Atack)

Pull request description:

  Follow-up to #11413 providing a base to build on for #19543:

  - bugfix for `bumpfee` raising a JSON error with explicit feerates, fixes issue #20219
  - adds explicit feerate test coverage for `bumpfee`, `fundrawtransaction`, `walletcreatefundedpsbt`, `send`, `sendtoaddress`, and `sendmany`
  - improves a few related RPC error messages and `ParseConfirmTarget()` / error message
  - fixes/improves the explicit fee rate information in the 6 RPC helps, of which 2 were also missing `conf_target` sat/B units

  This provides a spec and regression coverage for the potential next step of a universal `sat/vB` feerate argument (see #19543), as well as immediate coverage and minimum fixes for 0.21.

ACKs for top commit:
  kallewoof:
    Concept/Tested ACK 0be29000c0
  meshcollider:
    Code review + functional test run ACK 0be29000c0

Tree-SHA512: efd965003e991cba51d4504e2940f06ab3d742e34022e96a673606b44fad85596aa03a8c1809f06df7ebcf21a38e18a891e54392fe3d6fb4d120bbe4ea0cf5e0

test/functional/rpc_fundrawtransaction.py

@@ -8,6 +8,7 @@ from decimal import Decimal
 from test_framework.descriptors import descsum_create
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import (
+    assert_approx,
     assert_equal,
     assert_fee_amount,
     assert_greater_than,
@@ -89,6 +90,7 @@ class RawTransactionsTest(BitcoinTestFramework):
         self.test_op_return()
         self.test_watchonly()
         self.test_all_watched_funds()
+        self.test_feerate_with_conf_target_and_estimate_mode()
         self.test_option_feerate()
         self.test_address_reuse()
         self.test_option_subtract_fee_from_outputs()
@@ -722,6 +724,59 @@ class RawTransactionsTest(BitcoinTestFramework):
         assert_fee_amount(result2['fee'], count_bytes(result2['hex']), 2 * result_fee_rate)
         assert_fee_amount(result3['fee'], count_bytes(result3['hex']), 10 * result_fee_rate)
 
+    def test_feerate_with_conf_target_and_estimate_mode(self):
+        self.log.info("Test fundrawtxn passing an explicit fee rate using conf_target and estimate_mode")
+        node = self.nodes[3]
+        # Make sure there is exactly one input so coin selection can't skew the result.
+        assert_equal(len(node.listunspent(1)), 1)
+        inputs = []
+        outputs = {node.getnewaddress() : 1}
+        rawtx = node.createrawtransaction(inputs, outputs)
+
+        for unit, fee_rate in {"btc/kb": 0.1, "sat/b": 10000}.items():
+            self.log.info("Test fundrawtxn with conf_target {} estimate_mode {} produces expected fee".format(fee_rate, unit))
+            # With no arguments passed, expect fee of 141 sats/b.
+            assert_approx(node.fundrawtransaction(rawtx)["fee"], vexp=0.00000141, vspan=0.00000001)
+            # Expect fee to be 10,000x higher when explicit fee 10,000x greater is specified.
+            result = node.fundrawtransaction(rawtx, {"conf_target": fee_rate, "estimate_mode": unit})
+            assert_approx(result["fee"], vexp=0.0141, vspan=0.0001)
+
+        for field, fee_rate in {"conf_target": 0.1, "estimate_mode": "sat/b"}.items():
+            self.log.info("Test fundrawtxn raises RPC error if both feeRate and {} are passed".format(field))
+            assert_raises_rpc_error(
+                -8, "Cannot specify both {} and feeRate".format(field),
+                lambda: node.fundrawtransaction(rawtx, {"feeRate": 0.1, field: fee_rate}))
+
+        self.log.info("Test fundrawtxn with invalid estimate_mode settings")
+        for k, v in {"number": 42, "object": {"foo": "bar"}}.items():
+            assert_raises_rpc_error(-3, "Expected type string for estimate_mode, got {}".format(k),
+                lambda: self.nodes[1].fundrawtransaction(rawtx, {"estimate_mode": v, "conf_target": 0.1}))
+        for mode in ["foo", Decimal("3.141592")]:
+            assert_raises_rpc_error(-8, "Invalid estimate_mode parameter",
+                lambda: self.nodes[1].fundrawtransaction(rawtx, {"estimate_mode": mode, "conf_target": 0.1}))
+
+        self.log.info("Test fundrawtxn with invalid conf_target settings")
+        for mode in ["unset", "economical", "conservative", "btc/kb", "sat/b"]:
+            self.log.debug("{}".format(mode))
+            for k, v in {"string": "", "object": {"foo": "bar"}}.items():
+                assert_raises_rpc_error(-3, "Expected type number for conf_target, got {}".format(k),
+                    lambda: self.nodes[1].fundrawtransaction(rawtx, {"estimate_mode": mode, "conf_target": v}))
+            if mode in ["btc/kb", "sat/b"]:
+                assert_raises_rpc_error(-3, "Amount out of range",
+                    lambda: self.nodes[1].fundrawtransaction(rawtx, {"estimate_mode": mode, "conf_target": -1}))
+                assert_raises_rpc_error(-4, "Fee rate (0.00000000 BTC/kB) is lower than the minimum fee rate setting (0.00001000 BTC/kB)",
+                    lambda: self.nodes[1].fundrawtransaction(rawtx, {"estimate_mode": mode, "conf_target": 0}))
+            else:
+                for n in [-1, 0, 1009]:
+                    assert_raises_rpc_error(-8, "Invalid conf_target, must be between 1 and 1008",
+                        lambda: self.nodes[1].fundrawtransaction(rawtx, {"estimate_mode": mode, "conf_target": n}))
+
+        for unit, fee_rate in {"sat/B": 0.99999999, "BTC/kB": 0.00000999}.items():
+            self.log.info("- raises RPC error 'fee rate too low' if conf_target {} and estimate_mode {} are passed".format(fee_rate, unit))
+            assert_raises_rpc_error(-4, "Fee rate (0.00000999 BTC/kB) is lower than the minimum fee rate setting (0.00001000 BTC/kB)",
+                lambda: self.nodes[1].fundrawtransaction(rawtx, {"estimate_mode": unit, "conf_target": fee_rate, "add_inputs": True}))
+
+
     def test_address_reuse(self):
         """Test no address reuse occurs."""
         self.log.info("Test fundrawtxn does not reuse addresses")