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

Code before:

            # 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)
            assert_equal(tx_with_min_feerate["fee"], get_fee(tx_with_min_feerate["tx"].get_vsize(), blockmintxfee_btc_kvb))
            if blockmintxfee_btc_kvb > 0:
                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)
                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)
                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']]
            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
            assert tx_below_min_feerate['txid'] not in block_txids

    def test_timewarp(self):
        self.log.info("Test timewarp attack mitigation (BIP94)")
        node = self.nodes[0]
        self.restart_node(0, extra_args=['-test=bip94'])

        self.log.info("Mine until the last block of the retarget period")
        blockchain_info = self.nodes[0].getblockchaininfo()
        n = DIFFICULTY_ADJUSTMENT_INTERVAL - blockchain_info['blocks'] % DIFFICULTY_ADJUSTMENT_INTERVAL - 2
        t = blockchain_info['time']

        for _ in range(n):
            t += 600
            self.nodes[0].setmocktime(t)
            self.generate(self.wallet, 1, sync_fun=self.no_op)

        self.log.info("Create block two hours in the future")
        self.nodes[0].setmocktime(t + MAX_FUTURE_BLOCK_TIME)
        self.generate(self.wallet, 1, sync_fun=self.no_op)
        assert_equal(node.getblock(node.getbestblockhash())['time'], t + MAX_FUTURE_BLOCK_TIME)

        self.log.info("First block template of retarget period can't use wall clock time")
        self.nodes[0].setmocktime(t)
        # The template will have an adjusted timestamp, which we then modify
        tmpl = node.getblocktemplate(NORMAL_GBT_REQUEST_PARAMS)
        assert_greater_than_or_equal(tmpl['curtime'], t + MAX_FUTURE_BLOCK_TIME - MAX_TIMEWARP)
        # mintime and curtime should match
        assert_equal(tmpl['mintime'], tmpl['curtime'])

Review comment (suggestion):
nit: I think it's strange to let one test handle another test's pre's, would just keep this in `test_block_max_weight`?

<details>
<summary>git diff on c164064c26</summary>

```diff
diff --git a/test/functional/mining_basic.py b/test/functional/mining_basic.py
index 21451a9aaf..415a370b06 100755
--- a/test/functional/mining_basic.py
+++ b/test/functional/mining_basic.py
@@ -186,9 +186,6 @@ class MiningTest(BitcoinTestFramework):
             assert tx_below_min_feerate['txid'] not in block_template_txids
             assert tx_below_min_feerate['txid'] not in block_txids
 
-            # Restart node to clear mempool for the next test
-            self.restart_node(0)
-
     def test_timewarp(self):
         self.log.info("Test timewarp attack mitigation (BIP94)")
         node = self.nodes[0]
@@ -287,6 +284,7 @@ class MiningTest(BitcoinTestFramework):
         HIGH_FEERATE = Decimal("0.0003")
 
         # Ensure the mempool is empty
+        self.restart_node(0)
         assert_equal(len(self.nodes[0].getrawmempool()), 0)
 
         # Generate UTXOs and send 10 large transactions with a high fee rate

```
</details>


Code after:

            # 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)
            assert_equal(tx_with_min_feerate["fee"], get_fee(tx_with_min_feerate["tx"].get_vsize(), blockmintxfee_btc_kvb))
            if blockmintxfee_btc_kvb > 0:
                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)
                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)
                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']]
            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
            assert tx_below_min_feerate['txid'] not in block_txids

            # Restart node to clear mempool for the next test
            self.restart_node(0)

    def test_timewarp(self):
        self.log.info("Test timewarp attack mitigation (BIP94)")
        node = self.nodes[0]
        self.restart_node(0, extra_args=['-test=bip94'])

        self.log.info("Mine until the last block of the retarget period")
        blockchain_info = self.nodes[0].getblockchaininfo()
        n = DIFFICULTY_ADJUSTMENT_INTERVAL - blockchain_info['blocks'] % DIFFICULTY_ADJUSTMENT_INTERVAL - 2
        t = blockchain_info['time']

        for _ in range(n):
            t += 600
            self.nodes[0].setmocktime(t)
            self.generate(self.wallet, 1, sync_fun=self.no_op)

        self.log.info("Create block two hours in the future")
        self.nodes[0].setmocktime(t + MAX_FUTURE_BLOCK_TIME)
        self.generate(self.wallet, 1, sync_fun=self.no_op)
        assert_equal(node.getblock(node.getbestblockhash())['time'], t + MAX_FUTURE_BLOCK_TIME)

        self.log.info("First block template of retarget period can't use wall clock time")
        self.nodes[0].setmocktime(t)
        # The template will have an adjusted timestamp, which we then modify
        tmpl = node.getblocktemplate(NORMAL_GBT_REQUEST_PARAMS)