Repository: bitcoin/bitcoin
File: test/functional/mining_basic.py (Python)

Code before:
        block_template_sigops = [tx['sigops'] for tx in block_template_txs]
        assert_equal(block_template_sigops, [0, 4, 4, 4])

        # Clear mempool
        self.generate(self.wallet, 1, sync_fun=self.no_op)

    def test_blockmintxfee_parameter(self):
        self.log.info("Test -blockmintxfee setting")
        self.restart_node(0, extra_args=['-minrelaytxfee=0', '-persistmempool=0'])
        node = self.nodes[0]

        # test default (no parameter), zero and a bunch of arbitrary blockmintxfee rates [sat/kvB]
        for blockmintxfee_sat_kvb in (DEFAULT_BLOCK_MIN_TX_FEE, 0, 1, 5, 10, 50, 100, 500, 2500, 5000, 21000, 333333, 2500000):
            blockmintxfee_btc_kvb = blockmintxfee_sat_kvb / Decimal(COIN)
            if blockmintxfee_sat_kvb == DEFAULT_BLOCK_MIN_TX_FEE:
                self.log.info(f"-> Default -blockmintxfee setting ({blockmintxfee_sat_kvb} sat/kvB)...")
            else:
                blockmintxfee_parameter = f"-blockmintxfee={blockmintxfee_btc_kvb:.8f}"
                self.log.info(f"-> Test {blockmintxfee_parameter} ({blockmintxfee_sat_kvb} sat/kvB)...")
                self.restart_node(0, extra_args=[blockmintxfee_parameter, '-minrelaytxfee=0', '-persistmempool=0'])
                self.wallet.rescan_utxos()  # to avoid spending outputs of txs that are not in mempool anymore after restart

            # submit one tx with exactly the blockmintxfee rate, and one slightly below
            tx_with_min_feerate = self.wallet.send_self_transfer(from_node=node, fee_rate=blockmintxfee_btc_kvb, confirmed_only=True)
            assert_equal(tx_with_min_feerate["fee"], get_fee(tx_with_min_feerate["tx"].get_vsize(), blockmintxfee_btc_kvb))
            if blockmintxfee_sat_kvb > 5:
                lowerfee_btc_kvb = blockmintxfee_btc_kvb - Decimal(10)/COIN  # 0.01 sat/vbyte lower
                tx_below_min_feerate = self.wallet.send_self_transfer(from_node=node, fee_rate=lowerfee_btc_kvb, confirmed_only=True)
                assert_equal(tx_below_min_feerate["fee"], get_fee(tx_below_min_feerate["tx"].get_vsize(), lowerfee_btc_kvb))
            else:  # go below zero fee by using modified fees
                tx_below_min_feerate = self.wallet.send_self_transfer(from_node=node, fee_rate=blockmintxfee_btc_kvb, confirmed_only=True)
                node.prioritisetransaction(tx_below_min_feerate["txid"], 0, -1)

            # check that tx below specified fee-rate is neither in template nor in the actual block
            block_template = node.getblocktemplate(NORMAL_GBT_REQUEST_PARAMS)
            block_template_txids = [tx['txid'] for tx in block_template['transactions']]

            # Unless blockmintxfee is 0, the template shouldn't contain free transactions.
            # Note that the real block assembler uses package feerates, but we didn't create dependent transactions so it's ok to use base feerate.
            if blockmintxfee_btc_kvb > 0:
                for txid in block_template_txids:
                    tx = node.getmempoolentry(txid)
                    assert_greater_than(tx['fees']['base'], 0)

            self.generate(self.wallet, 1, sync_fun=self.no_op)
            block = node.getblock(node.getbestblockhash(), verbosity=2)
            block_txids = [tx['txid'] for tx in block['tx']]

            assert tx_with_min_feerate['txid'] in block_template_txids
            assert tx_with_min_feerate['txid'] in block_txids
            assert tx_below_min_feerate['txid'] not in block_template_txids

Review comment (suggestion):
feel-free-to-disregard-nit, better expresses the reason for the check:
```suggestion
            if blockmintxfee_sat_kvb >= 10
```

Code after:
        block_template_sigops = [tx['sigops'] for tx in block_template_txs]
        assert_equal(block_template_sigops, [0, 4, 4, 4])

        # Clear mempool
        self.generate(self.wallet, 1, sync_fun=self.no_op)

    def test_blockmintxfee_parameter(self):
        self.log.info("Test -blockmintxfee setting")
        self.restart_node(0, extra_args=['-minrelaytxfee=0', '-persistmempool=0'])
        node = self.nodes[0]

        # test default (no parameter), zero and a bunch of arbitrary blockmintxfee rates [sat/kvB]
        for blockmintxfee_sat_kvb in (DEFAULT_BLOCK_MIN_TX_FEE, 0, 5, 10, 50, 100, 500, 1000, 2500, 5000, 21000, 333333, 2500000):
            blockmintxfee_btc_kvb = blockmintxfee_sat_kvb / Decimal(COIN)
            if blockmintxfee_sat_kvb == DEFAULT_BLOCK_MIN_TX_FEE:
                self.log.info(f"-> Default -blockmintxfee setting ({blockmintxfee_sat_kvb} sat/kvB)...")
            else:
                blockmintxfee_parameter = f"-blockmintxfee={blockmintxfee_btc_kvb:.8f}"
                self.log.info(f"-> Test {blockmintxfee_parameter} ({blockmintxfee_sat_kvb} sat/kvB)...")
                self.restart_node(0, extra_args=[blockmintxfee_parameter, '-minrelaytxfee=0', '-persistmempool=0'])
                self.wallet.rescan_utxos()  # to avoid spending outputs of txs that are not in mempool anymore after restart

            # submit one tx with exactly the blockmintxfee rate, and one slightly below
            tx_with_min_feerate = self.wallet.send_self_transfer(from_node=node, fee_rate=blockmintxfee_btc_kvb, confirmed_only=True)
            assert_equal(tx_with_min_feerate["fee"], get_fee(tx_with_min_feerate["tx"].get_vsize(), blockmintxfee_btc_kvb))
            if blockmintxfee_sat_kvb > 5:
                lowerfee_btc_kvb = blockmintxfee_btc_kvb - Decimal(10)/COIN  # 0.01 sat/vbyte lower
                tx_below_min_feerate = self.wallet.send_self_transfer(from_node=node, fee_rate=lowerfee_btc_kvb, confirmed_only=True)
                assert_equal(tx_below_min_feerate["fee"], get_fee(tx_below_min_feerate["tx"].get_vsize(), lowerfee_btc_kvb))
            else:  # go below zero fee by using modified fees
                tx_below_min_feerate = self.wallet.send_self_transfer(from_node=node, fee_rate=blockmintxfee_btc_kvb, confirmed_only=True)
                node.prioritisetransaction(tx_below_min_feerate["txid"], 0, -1)

            # check that tx below specified fee-rate is neither in template nor in the actual block
            block_template = node.getblocktemplate(NORMAL_GBT_REQUEST_PARAMS)
            block_template_txids = [tx['txid'] for tx in block_template['transactions']]

            # Unless blockmintxfee is 0, the template shouldn't contain free transactions.
            # Note that the real block assembler uses package feerates, but we didn't create dependent transactions so it's ok to use base feerate.
            if blockmintxfee_btc_kvb > 0:
                for txid in block_template_txids:
                    tx = node.getmempoolentry(txid)
                    assert_greater_than(tx['fees']['base'], 0)

            self.generate(self.wallet, 1, sync_fun=self.no_op)
            block = node.getblock(node.getbestblockhash(), verbosity=2)
            block_txids = [tx['txid'] for tx in block['tx']]

            assert tx_with_min_feerate['txid'] in block_template_txids
            assert tx_with_min_feerate['txid'] in block_txids
            assert tx_below_min_feerate['txid'] not in block_template_txids