Merge #20159: test: mining_getblocktemplate_longpoll.py improvements (use MiniWallet, add logging)

b128b566725a5037fdaea99940d1b9de5553d198 test: add logging for mining_getblocktemplate_longpoll.py (Sebastian Falbesoner)
8ee3536b2b77aeb3a48df5b34effbc7345ef34d8 test: remove unused helpers random_transaction(), make_change() and gather_inputs() (Sebastian Falbesoner)
fddce7e199308d96e366d700dca982ef088ba98b test: use MiniWallet for mining_getblocktemplate_longpoll.py (Sebastian Falbesoner)

Pull request description:

  This PR enables one more of the non-wallet functional tests (mining_getblocktemplate_longpoll.py) to be run even with the Bitcoin Core wallet disabled by using the new MiniWallet instead, as proposed in #20078. Also adds missing log messages for the subtests.

  This was the only functional test that used the `random_transaction` helper in `test_framework/util.py`, hence it is removed, together with other helpers (`make_change` and `gather_inputs`) that were again only used by `random_transaction`.

ACKs for top commit:
  MarcoFalke:
    ACK b128b566725a5037fdaea99940d1b9de5553d198

Tree-SHA512: 09a5fa7b0f5976a47040f7027236d7ec0426d5a4829a082221c4b5fae294470230e89ae3df0bca0eea26833162c03980517f5cc88761ad251c3df4c4a49bca46

2 files changed, 19 insertions, 71 deletions

diff --git a/test/functional/mining_getblocktemplate_longpoll.py b/test/functional/mining_getblocktemplate_longpoll.py
index 6d0b241e57..2adafb1fdb 100755
--- a/test/functional/mining_getblocktemplate_longpoll.py
+++ b/test/functional/mining_getblocktemplate_longpoll.py
@@ -5,11 +5,13 @@
 """Test longpolling with getblocktemplate."""
 
 from decimal import Decimal
+import random
+import threading
 
 from test_framework.test_framework import BitcoinTestFramework
-from test_framework.util import get_rpc_proxy, random_transaction
+from test_framework.util import get_rpc_proxy
+from test_framework.wallet import MiniWallet
 
-import threading
 
 class LongpollThread(threading.Thread):
     def __init__(self, node):
@@ -29,45 +31,48 @@ class GetBlockTemplateLPTest(BitcoinTestFramework):
         self.num_nodes = 2
         self.supports_cli = False
 
-    def skip_test_if_missing_module(self):
-        self.skip_if_no_wallet()
-
     def run_test(self):
         self.log.info("Warning: this test will take about 70 seconds in the best case. Be patient.")
+        self.log.info("Test that longpollid doesn't change between successive getblocktemplate() invocations if nothing else happens")
         self.nodes[0].generate(10)
         template = self.nodes[0].getblocktemplate({'rules': ['segwit']})
         longpollid = template['longpollid']
-        # longpollid should not change between successive invocations if nothing else happens
         template2 = self.nodes[0].getblocktemplate({'rules': ['segwit']})
         assert template2['longpollid'] == longpollid
 
-        # Test 1: test that the longpolling wait if we do nothing
+        self.log.info("Test that longpoll waits if we do nothing")
         thr = LongpollThread(self.nodes[0])
         thr.start()
         # check that thread still lives
         thr.join(5)  # wait 5 seconds or until thread exits
         assert thr.is_alive()
 
-        # Test 2: test that longpoll will terminate if another node generates a block
-        self.nodes[1].generate(1)  # generate a block on another node
+        miniwallets = [ MiniWallet(node) for node in self.nodes ]
+        self.log.info("Test that longpoll will terminate if another node generates a block")
+        miniwallets[1].generate(1)  # generate a block on another node
         # check that thread will exit now that new transaction entered mempool
         thr.join(5)  # wait 5 seconds or until thread exits
         assert not thr.is_alive()
 
-        # Test 3: test that longpoll will terminate if we generate a block ourselves
+        self.log.info("Test that longpoll will terminate if we generate a block ourselves")
         thr = LongpollThread(self.nodes[0])
         thr.start()
-        self.nodes[0].generate(1)  # generate a block on another node
+        miniwallets[0].generate(1)  # generate a block on own node
         thr.join(5)  # wait 5 seconds or until thread exits
         assert not thr.is_alive()
 
-        # Test 4: test that introducing a new transaction into the mempool will terminate the longpoll
+        # Add enough mature utxos to the wallets, so that all txs spend confirmed coins
+        self.nodes[0].generate(100)
+        self.sync_blocks()
+
+        self.log.info("Test that introducing a new transaction into the mempool will terminate the longpoll")
         thr = LongpollThread(self.nodes[0])
         thr.start()
         # generate a random transaction and submit it
         min_relay_fee = self.nodes[0].getnetworkinfo()["relayfee"]
-        # min_relay_fee is fee per 1000 bytes, which should be more than enough.
-        (txid, txhex, fee) = random_transaction(self.nodes, Decimal("1.1"), min_relay_fee, Decimal("0.001"), 20)
+        fee_rate = min_relay_fee + Decimal('0.00000010') * random.randint(0,20)
+        miniwallets[0].send_self_transfer(from_node=random.choice(self.nodes),
+                                          fee_rate=fee_rate)
         # after one minute, every 10 seconds the mempool is probed, so in 80 seconds it should have returned
         thr.join(60 + 20)
         assert not thr.is_alive()
diff --git a/test/functional/test_framework/util.py b/test/functional/test_framework/util.py
index af7f0b62f4..7688febae7 100644
--- a/test/functional/test_framework/util.py
+++ b/test/functional/test_framework/util.py
@@ -12,7 +12,6 @@ import inspect
 import json
 import logging
 import os
-import random
 import re
 import time
 import unittest
@@ -469,62 +468,6 @@ def find_output(node, txid, amount, *, blockhash=None):
     raise RuntimeError("find_output txid %s : %s not found" % (txid, str(amount)))
 
 
-def gather_inputs(from_node, amount_needed, confirmations_required=1):
-    """
-    Return a random set of unspent txouts that are enough to pay amount_needed
-    """
-    assert confirmations_required >= 0
-    utxo = from_node.listunspent(confirmations_required)
-    random.shuffle(utxo)
-    inputs = []
-    total_in = Decimal("0.00000000")
-    while total_in < amount_needed and len(utxo) > 0:
-        t = utxo.pop()
-        total_in += t["amount"]
-        inputs.append({"txid": t["txid"], "vout": t["vout"], "address": t["address"]})
-    if total_in < amount_needed:
-        raise RuntimeError("Insufficient funds: need %d, have %d" % (amount_needed, total_in))
-    return (total_in, inputs)
-
-
-def make_change(from_node, amount_in, amount_out, fee):
-    """
-    Create change output(s), return them
-    """
-    outputs = {}
-    amount = amount_out + fee
-    change = amount_in - amount
-    if change > amount * 2:
-        # Create an extra change output to break up big inputs
-        change_address = from_node.getnewaddress()
-        # Split change in two, being careful of rounding:
-        outputs[change_address] = Decimal(change / 2).quantize(Decimal('0.00000001'), rounding=ROUND_DOWN)
-        change = amount_in - amount - outputs[change_address]
-    if change > 0:
-        outputs[from_node.getnewaddress()] = change
-    return outputs
-
-
-def random_transaction(nodes, amount, min_fee, fee_increment, fee_variants):
-    """
-    Create a random transaction.
-    Returns (txid, hex-encoded-transaction-data, fee)
-    """
-    from_node = random.choice(nodes)
-    to_node = random.choice(nodes)
-    fee = min_fee + fee_increment * random.randint(0, fee_variants)
-
-    (total_in, inputs) = gather_inputs(from_node, amount + fee)
-    outputs = make_change(from_node, total_in, amount, fee)
-    outputs[to_node.getnewaddress()] = float(amount)
-
-    rawtx = from_node.createrawtransaction(inputs, outputs)
-    signresult = from_node.signrawtransactionwithwallet(rawtx)
-    txid = from_node.sendrawtransaction(signresult["hex"], 0)
-
-    return (txid, signresult["hex"], fee)
-
-
 # Helper to create at least "count" utxos
 # Pass in a fee that is sufficient for relay and mining new transactions.
 def create_confirmed_utxos(fee, node, count):