Merge #13669: Tests: Cleanup create_transaction implementations

44bbceeef1 [Tests] Cleanup feature_block.py, remove unnecessary PreviousSpendableOutput object (Conor Scott)
736f941424 [Tests] Cleanup extra instances of create_transaction (Conor Scott)
157651855f [Tests] Rename create_tx and move to blocktools.py (Conor Scott)

Pull request description:

  There currently exist seven ([1](https://github.com/bitcoin/bitcoin/blob/master/test/functional/feature_cltv.py#L52-L60), [2](https://github.com/bitcoin/bitcoin/blob/master/test/functional/feature_csv_activation.py#L88-L95) [3](https://github.com/bitcoin/bitcoin/blob/master/test/functional/feature_dersig.py#L40-L48), [4](https://github.com/bitcoin/bitcoin/blob/master/test/functional/feature_nulldummy.py#L100-L108), [5](https://github.com/bitcoin/bitcoin/blob/master/test/functional/test_framework/util.py#L529-L535), [6](https://github.com/bitcoin/bitcoin/blob/master/test/functional/test_framework/blocktools.py#L120-L129), [7](https://github.com/bitcoin/bitcoin/blob/master/test/functional/feature_block.py#L1218-L1220)) implementations of a function called something similar to `create_transaction` in the functional tests, some of which are exact copies of each other.

  This PR aims to clean this up into [three different cases implemented in blocktools.py](https://github.com/conscott/bitcoin/blob/create_tx_cleanup/test/functional/test_framework/blocktools.py#L121-L149)
  1. `create_tx_with_script`: Return transaction object spending generic tx output optionally specifying scriptSig and scriptPubKey
  2. `create_transaction`: Return transaction object spending coinbase tx
  2. `create_raw_transaction`: Return raw transaction (hex string) spending coinbase tx

  I am not committed to any of these function names, so I'll gladly take suggestions on there.

  Additionally there are some related cleanups to feature_block.py tests, specifically removing the [PreviousSpendableOutput](https://github.com/conscott/bitcoin/blob/master/test/functional/feature_block.py#L51-L54) object, which seems like an unnecessary layer given that every instance spends the 0 output.

Tree-SHA512: 63c6233b6f0942c81ba1ca67ea6770809b8c9409314c6d4cf8e5a3991cb9ee92b22bebe88c0dde45cd71e754eb351230c4c404b70ff118f5f43c034452ada65c

13 files changed, 112 insertions, 137 deletions

diff --git a/test/functional/feature_block.py b/test/functional/feature_block.py
index b230f1c9c2..79ed902871 100755
--- a/test/functional/feature_block.py
+++ b/test/functional/feature_block.py
@@ -7,7 +7,7 @@ import copy
 import struct
 import time
 
-from test_framework.blocktools import create_block, create_coinbase, create_transaction, get_legacy_sigopcount_block
+from test_framework.blocktools import create_block, create_coinbase, create_tx_with_script, get_legacy_sigopcount_block
 from test_framework.key import CECKey
 from test_framework.messages import (
     CBlock,
@@ -48,11 +48,6 @@ from test_framework.util import assert_equal
 
 MAX_BLOCK_SIGOPS = 20000
 
-class PreviousSpendableOutput():
-    def __init__(self, tx=CTransaction(), n=-1):
-        self.tx = tx
-        self.n = n  # the output we're spending
-
 #  Use this class for tests that require behavior other than normal "mininode" behavior.
 #  For now, it is used to serialize a bloated varint (b64).
 class CBrokenBlock(CBlock):
@@ -132,7 +127,7 @@ class FullBlockTest(BitcoinTestFramework):
         self.log.info("Don't reorg to a chain of the same length")
         self.move_tip(1)
         b3 = self.next_block(3, spend=out[1])
-        txout_b3 = PreviousSpendableOutput(b3.vtx[1], 0)
+        txout_b3 = b3.vtx[1]
         self.sync_blocks([b3], False)
 
         # Now we add another block to make the alternative chain longer.
@@ -397,8 +392,8 @@ class FullBlockTest(BitcoinTestFramework):
         self.log.info("Reject a block spending transaction from a block which failed to connect")
         self.move_tip(35)
         b37 = self.next_block(37, spend=out[11])
-        txout_b37 = PreviousSpendableOutput(b37.vtx[1], 0)
-        tx = self.create_and_sign_transaction(out[11].tx, out[11].n, 0)
+        txout_b37 = b37.vtx[1]
+        tx = self.create_and_sign_transaction(out[11], 0)
         b37 = self.update_block(37, [tx])
         self.sync_blocks([b37], False, 16, b'bad-txns-inputs-missingorspent', reconnect=True)
 
@@ -432,9 +427,9 @@ class FullBlockTest(BitcoinTestFramework):
         # Create a transaction that spends one satoshi to the p2sh_script, the rest to OP_TRUE
         # This must be signed because it is spending a coinbase
         spend = out[11]
-        tx = self.create_tx(spend.tx, spend.n, 1, p2sh_script)
-        tx.vout.append(CTxOut(spend.tx.vout[spend.n].nValue - 1, CScript([OP_TRUE])))
-        self.sign_tx(tx, spend.tx, spend.n)
+        tx = self.create_tx(spend, 0, 1, p2sh_script)
+        tx.vout.append(CTxOut(spend.vout[0].nValue - 1, CScript([OP_TRUE])))
+        self.sign_tx(tx, spend)
         tx.rehash()
         b39 = self.update_block(39, [tx])
         b39_outputs += 1
@@ -548,7 +543,7 @@ class FullBlockTest(BitcoinTestFramework):
         self.sync_blocks([b44], True)
 
         self.log.info("Reject a block with a non-coinbase as the first tx")
-        non_coinbase = self.create_tx(out[15].tx, out[15].n, 1)
+        non_coinbase = self.create_tx(out[15], 0, 1)
         b45 = CBlock()
         b45.nTime = self.tip.nTime + 1
         b45.hashPrevBlock = self.tip.sha256
@@ -675,7 +670,7 @@ class FullBlockTest(BitcoinTestFramework):
         # b57 - a good block with 2 txs, don't submit until end
         self.move_tip(55)
         b57 = self.next_block(57)
-        tx = self.create_and_sign_transaction(out[16].tx, out[16].n, 1)
+        tx = self.create_and_sign_transaction(out[16], 1)
         tx1 = self.create_tx(tx, 0, 1)
         b57 = self.update_block(57, [tx, tx1])
 
@@ -692,7 +687,7 @@ class FullBlockTest(BitcoinTestFramework):
         # b57p2 - a good block with 6 tx'es, don't submit until end
         self.move_tip(55)
         b57p2 = self.next_block("57p2")
-        tx = self.create_and_sign_transaction(out[16].tx, out[16].n, 1)
+        tx = self.create_and_sign_transaction(out[16], 1)
         tx1 = self.create_tx(tx, 0, 1)
         tx2 = self.create_tx(tx1, 0, 1)
         tx3 = self.create_tx(tx2, 0, 1)
@@ -727,8 +722,8 @@ class FullBlockTest(BitcoinTestFramework):
         self.move_tip(57)
         b58 = self.next_block(58, spend=out[17])
         tx = CTransaction()
-        assert(len(out[17].tx.vout) < 42)
-        tx.vin.append(CTxIn(COutPoint(out[17].tx.sha256, 42), CScript([OP_TRUE]), 0xffffffff))
+        assert(len(out[17].vout) < 42)
+        tx.vin.append(CTxIn(COutPoint(out[17].sha256, 42), CScript([OP_TRUE]), 0xffffffff))
         tx.vout.append(CTxOut(0, b""))
         tx.calc_sha256()
         b58 = self.update_block(58, [tx])
@@ -738,7 +733,7 @@ class FullBlockTest(BitcoinTestFramework):
         self.log.info("Reject a block with a transaction with outputs > inputs")
         self.move_tip(57)
         b59 = self.next_block(59)
-        tx = self.create_and_sign_transaction(out[17].tx, out[17].n, 51 * COIN)
+        tx = self.create_and_sign_transaction(out[17], 51 * COIN)
         b59 = self.update_block(59, [tx])
         self.sync_blocks([b59], False, 16, b'bad-txns-in-belowout', reconnect=True)
 
@@ -776,8 +771,7 @@ class FullBlockTest(BitcoinTestFramework):
         b62 = self.next_block(62)
         tx = CTransaction()
         tx.nLockTime = 0xffffffff  # this locktime is non-final
-        assert(out[18].n < len(out[18].tx.vout))
-        tx.vin.append(CTxIn(COutPoint(out[18].tx.sha256, out[18].n)))  # don't set nSequence
+        tx.vin.append(CTxIn(COutPoint(out[18].sha256, 0)))  # don't set nSequence
         tx.vout.append(CTxOut(0, CScript([OP_TRUE])))
         assert(tx.vin[0].nSequence < 0xffffffff)
         tx.calc_sha256()
@@ -856,8 +850,8 @@ class FullBlockTest(BitcoinTestFramework):
         self.log.info("Accept a block with a transaction spending an output created in the same block")
         self.move_tip(64)
         b65 = self.next_block(65)
-        tx1 = self.create_and_sign_transaction(out[19].tx, out[19].n, out[19].tx.vout[0].nValue)
-        tx2 = self.create_and_sign_transaction(tx1, 0, 0)
+        tx1 = self.create_and_sign_transaction(out[19], out[19].vout[0].nValue)
+        tx2 = self.create_and_sign_transaction(tx1, 0)
         b65 = self.update_block(65, [tx1, tx2])
         self.sync_blocks([b65], True)
         self.save_spendable_output()
@@ -869,8 +863,8 @@ class FullBlockTest(BitcoinTestFramework):
         self.log.info("Reject a block with a transaction spending an output created later in the same block")
         self.move_tip(65)
         b66 = self.next_block(66)
-        tx1 = self.create_and_sign_transaction(out[20].tx, out[20].n, out[20].tx.vout[0].nValue)
-        tx2 = self.create_and_sign_transaction(tx1, 0, 1)
+        tx1 = self.create_and_sign_transaction(out[20], out[20].vout[0].nValue)
+        tx2 = self.create_and_sign_transaction(tx1, 1)
         b66 = self.update_block(66, [tx2, tx1])
         self.sync_blocks([b66], False, 16, b'bad-txns-inputs-missingorspent', reconnect=True)
 
@@ -883,9 +877,9 @@ class FullBlockTest(BitcoinTestFramework):
         self.log.info("Reject a block with a transaction double spending a transaction creted in the same block")
         self.move_tip(65)
         b67 = self.next_block(67)
-        tx1 = self.create_and_sign_transaction(out[20].tx, out[20].n, out[20].tx.vout[0].nValue)
-        tx2 = self.create_and_sign_transaction(tx1, 0, 1)
-        tx3 = self.create_and_sign_transaction(tx1, 0, 2)
+        tx1 = self.create_and_sign_transaction(out[20], out[20].vout[0].nValue)
+        tx2 = self.create_and_sign_transaction(tx1, 1)
+        tx3 = self.create_and_sign_transaction(tx1, 2)
         b67 = self.update_block(67, [tx1, tx2, tx3])
         self.sync_blocks([b67], False, 16, b'bad-txns-inputs-missingorspent', reconnect=True)
 
@@ -904,14 +898,14 @@ class FullBlockTest(BitcoinTestFramework):
         self.log.info("Reject a block trying to claim too much subsidy in the coinbase transaction")
         self.move_tip(65)
         b68 = self.next_block(68, additional_coinbase_value=10)
-        tx = self.create_and_sign_transaction(out[20].tx, out[20].n, out[20].tx.vout[0].nValue - 9)
+        tx = self.create_and_sign_transaction(out[20], out[20].vout[0].nValue - 9)
         b68 = self.update_block(68, [tx])
         self.sync_blocks([b68], False, 16, b'bad-cb-amount', reconnect=True)
 
         self.log.info("Accept a block claiming the correct subsidy in the coinbase transaction")
         self.move_tip(65)
         b69 = self.next_block(69, additional_coinbase_value=10)
-        tx = self.create_and_sign_transaction(out[20].tx, out[20].n, out[20].tx.vout[0].nValue - 10)
+        tx = self.create_and_sign_transaction(out[20], out[20].vout[0].nValue - 10)
         self.update_block(69, [tx])
         self.sync_blocks([b69], True)
         self.save_spendable_output()
@@ -942,8 +936,8 @@ class FullBlockTest(BitcoinTestFramework):
         self.log.info("Reject a block containing a duplicate transaction but with the same Merkle root (Merkle tree malleability")
         self.move_tip(69)
         b72 = self.next_block(72)
-        tx1 = self.create_and_sign_transaction(out[21].tx, out[21].n, 2)
-        tx2 = self.create_and_sign_transaction(tx1, 0, 1)
+        tx1 = self.create_and_sign_transaction(out[21], 2)
+        tx2 = self.create_and_sign_transaction(tx1, 1)
         b72 = self.update_block(72, [tx1, tx2])  # now tip is 72
         b71 = copy.deepcopy(b72)
         b71.vtx.append(tx2)   # add duplicate tx2
@@ -990,7 +984,7 @@ class FullBlockTest(BitcoinTestFramework):
         a[MAX_BLOCK_SIGOPS + 2] = 0
         a[MAX_BLOCK_SIGOPS + 3] = 0
 
-        tx = self.create_and_sign_transaction(out[22].tx, 0, 1, CScript(a))
+        tx = self.create_and_sign_transaction(out[22], 1, CScript(a))
         b73 = self.update_block(73, [tx])
         assert_equal(get_legacy_sigopcount_block(b73), MAX_BLOCK_SIGOPS + 1)
         self.sync_blocks([b73], False, 16, b'bad-blk-sigops', reconnect=True)
@@ -1015,7 +1009,7 @@ class FullBlockTest(BitcoinTestFramework):
         a[MAX_BLOCK_SIGOPS + 2] = 0xff
         a[MAX_BLOCK_SIGOPS + 3] = 0xff
         a[MAX_BLOCK_SIGOPS + 4] = 0xff
-        tx = self.create_and_sign_transaction(out[22].tx, 0, 1, CScript(a))
+        tx = self.create_and_sign_transaction(out[22], 1, CScript(a))
         b74 = self.update_block(74, [tx])
         self.sync_blocks([b74], False, 16, b'bad-blk-sigops', reconnect=True)
 
@@ -1028,7 +1022,7 @@ class FullBlockTest(BitcoinTestFramework):
         a[MAX_BLOCK_SIGOPS + 1] = 0xff
         a[MAX_BLOCK_SIGOPS + 2] = 0xff
         a[MAX_BLOCK_SIGOPS + 3] = 0xff
-        tx = self.create_and_sign_transaction(out[22].tx, 0, 1, CScript(a))
+        tx = self.create_and_sign_transaction(out[22], 1, CScript(a))
         b75 = self.update_block(75, [tx])
         self.sync_blocks([b75], True)
         self.save_spendable_output()
@@ -1039,7 +1033,7 @@ class FullBlockTest(BitcoinTestFramework):
         size = MAX_BLOCK_SIGOPS - 1 + MAX_SCRIPT_ELEMENT_SIZE + 1 + 5
         a = bytearray([OP_CHECKSIG] * size)
         a[MAX_BLOCK_SIGOPS - 1] = 0x4e  # PUSHDATA4, but leave the following bytes as just checksigs
-        tx = self.create_and_sign_transaction(out[23].tx, 0, 1, CScript(a))
+        tx = self.create_and_sign_transaction(out[23], 1, CScript(a))
         b76 = self.update_block(76, [tx])
         self.sync_blocks([b76], True)
         self.save_spendable_output()
@@ -1064,7 +1058,7 @@ class FullBlockTest(BitcoinTestFramework):
         self.log.info("Test transaction resurrection during a re-org")
         self.move_tip(76)
         b77 = self.next_block(77)
-        tx77 = self.create_and_sign_transaction(out[24].tx, out[24].n, 10 * COIN)
+        tx77 = self.create_and_sign_transaction(out[24], 10 * COIN)
         b77 = self.update_block(77, [tx77])
         self.sync_blocks([b77], True)
         self.save_spendable_output()
@@ -1109,9 +1103,9 @@ class FullBlockTest(BitcoinTestFramework):
         b83 = self.next_block(83)
         op_codes = [OP_IF, OP_INVALIDOPCODE, OP_ELSE, OP_TRUE, OP_ENDIF]
         script = CScript(op_codes)
-        tx1 = self.create_and_sign_transaction(out[28].tx, out[28].n, out[28].tx.vout[0].nValue, script)
+        tx1 = self.create_and_sign_transaction(out[28], out[28].vout[0].nValue, script)
 
-        tx2 = self.create_and_sign_transaction(tx1, 0, 0, CScript([OP_TRUE]))
+        tx2 = self.create_and_sign_transaction(tx1, 0, CScript([OP_TRUE]))
         tx2.vin[0].scriptSig = CScript([OP_FALSE])
         tx2.rehash()
 
@@ -1126,13 +1120,13 @@ class FullBlockTest(BitcoinTestFramework):
         #
         self.log.info("Test re-orging blocks with OP_RETURN in them")
         b84 = self.next_block(84)
-        tx1 = self.create_tx(out[29].tx, out[29].n, 0, CScript([OP_RETURN]))
+        tx1 = self.create_tx(out[29], 0, 0, CScript([OP_RETURN]))
         tx1.vout.append(CTxOut(0, CScript([OP_TRUE])))
         tx1.vout.append(CTxOut(0, CScript([OP_TRUE])))
         tx1.vout.append(CTxOut(0, CScript([OP_TRUE])))
         tx1.vout.append(CTxOut(0, CScript([OP_TRUE])))
         tx1.calc_sha256()
-        self.sign_tx(tx1, out[29].tx, out[29].n)
+        self.sign_tx(tx1, out[29])
         tx1.rehash()
         tx2 = self.create_tx(tx1, 1, 0, CScript([OP_RETURN]))
         tx2.vout.append(CTxOut(0, CScript([OP_RETURN])))
@@ -1217,21 +1211,21 @@ class FullBlockTest(BitcoinTestFramework):
 
     # this is a little handier to use than the version in blocktools.py
     def create_tx(self, spend_tx, n, value, script=CScript([OP_TRUE, OP_DROP] * 15 + [OP_TRUE])):
-        return create_transaction(spend_tx, n, b"", value, script)
+        return create_tx_with_script(spend_tx, n, amount=value, script_pub_key=script)
 
     # sign a transaction, using the key we know about
     # this signs input 0 in tx, which is assumed to be spending output n in spend_tx
-    def sign_tx(self, tx, spend_tx, n):
-        scriptPubKey = bytearray(spend_tx.vout[n].scriptPubKey)
+    def sign_tx(self, tx, spend_tx):
+        scriptPubKey = bytearray(spend_tx.vout[0].scriptPubKey)
         if (scriptPubKey[0] == OP_TRUE):  # an anyone-can-spend
             tx.vin[0].scriptSig = CScript()
             return
-        (sighash, err) = SignatureHash(spend_tx.vout[n].scriptPubKey, tx, 0, SIGHASH_ALL)
+        (sighash, err) = SignatureHash(spend_tx.vout[0].scriptPubKey, tx, 0, SIGHASH_ALL)
         tx.vin[0].scriptSig = CScript([self.coinbase_key.sign(sighash) + bytes(bytearray([SIGHASH_ALL]))])
 
-    def create_and_sign_transaction(self, spend_tx, n, value, script=CScript([OP_TRUE])):
-        tx = self.create_tx(spend_tx, n, value, script)
-        self.sign_tx(tx, spend_tx, n)
+    def create_and_sign_transaction(self, spend_tx, value, script=CScript([OP_TRUE])):
+        tx = self.create_tx(spend_tx, 0, value, script)
+        self.sign_tx(tx, spend_tx)
         tx.rehash()
         return tx
 
@@ -1250,11 +1244,11 @@ class FullBlockTest(BitcoinTestFramework):
         if spend is None:
             block = create_block(base_block_hash, coinbase, block_time)
         else:
-            coinbase.vout[0].nValue += spend.tx.vout[spend.n].nValue - 1  # all but one satoshi to fees
+            coinbase.vout[0].nValue += spend.vout[0].nValue - 1  # all but one satoshi to fees
             coinbase.rehash()
             block = create_block(base_block_hash, coinbase, block_time)
-            tx = create_transaction(spend.tx, spend.n, b"", 1, script)  # spend 1 satoshi
-            self.sign_tx(tx, spend.tx, spend.n)
+            tx = self.create_tx(spend, 0, 1, script)  # spend 1 satoshi
+            self.sign_tx(tx, spend)
             self.add_transactions_to_block(block, [tx])
             block.hashMerkleRoot = block.calc_merkle_root()
         if solve:
@@ -1273,7 +1267,7 @@ class FullBlockTest(BitcoinTestFramework):
     # get an output that we previously marked as spendable
     def get_spendable_output(self):
         self.log.debug("getting spendable output %s" % self.spendable_outputs[0].vtx[0])
-        return PreviousSpendableOutput(self.spendable_outputs.pop(0).vtx[0], 0)
+        return self.spendable_outputs.pop(0).vtx[0]
 
     # move the tip back to a previous block
     def move_tip(self, number):
diff --git a/test/functional/feature_cltv.py b/test/functional/feature_cltv.py
index ca35def3ce..cc59ea8c9b 100755
--- a/test/functional/feature_cltv.py
+++ b/test/functional/feature_cltv.py
@@ -11,7 +11,7 @@ Test that the CHECKLOCKTIMEVERIFY soft-fork activates at (regtest) block height
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import *
 from test_framework.mininode import *
-from test_framework.blocktools import create_coinbase, create_block
+from test_framework.blocktools import create_coinbase, create_block, create_transaction
 from test_framework.script import CScript, OP_1NEGATE, OP_CHECKLOCKTIMEVERIFY, OP_DROP, CScriptNum
 from io import BytesIO
 
@@ -49,16 +49,6 @@ def cltv_validate(node, tx, height):
                                   list(CScript(new_tx.vin[0].scriptSig)))
     return new_tx
 
-def create_transaction(node, coinbase, to_address, amount):
-    from_txid = node.getblock(coinbase)['tx'][0]
-    inputs = [{ "txid" : from_txid, "vout" : 0}]
-    outputs = { to_address : amount }
-    rawtx = node.createrawtransaction(inputs, outputs)
-    signresult = node.signrawtransactionwithwallet(rawtx)
-    tx = CTransaction()
-    tx.deserialize(BytesIO(hex_str_to_bytes(signresult['hex'])))
-    return tx
-
 class BIP65Test(BitcoinTestFramework):
     def set_test_params(self):
         self.num_nodes = 1
@@ -69,12 +59,12 @@ class BIP65Test(BitcoinTestFramework):
         self.nodes[0].add_p2p_connection(P2PInterface())
 
         self.log.info("Mining %d blocks", CLTV_HEIGHT - 2)
-        self.coinbase_blocks = self.nodes[0].generate(CLTV_HEIGHT - 2)
+        self.coinbase_txids = [self.nodes[0].getblock(b)['tx'][0] for b in self.nodes[0].generate(CLTV_HEIGHT - 2)]
         self.nodeaddress = self.nodes[0].getnewaddress()
 
         self.log.info("Test that an invalid-according-to-CLTV transaction can still appear in a block")
 
-        spendtx = create_transaction(self.nodes[0], self.coinbase_blocks[0],
+        spendtx = create_transaction(self.nodes[0], self.coinbase_txids[0],
                 self.nodeaddress, 1.0)
         cltv_invalidate(spendtx)
         spendtx.rehash()
@@ -109,7 +99,7 @@ class BIP65Test(BitcoinTestFramework):
         self.log.info("Test that invalid-according-to-cltv transactions cannot appear in a block")
         block.nVersion = 4
 
-        spendtx = create_transaction(self.nodes[0], self.coinbase_blocks[1],
+        spendtx = create_transaction(self.nodes[0], self.coinbase_txids[1],
                 self.nodeaddress, 1.0)
         cltv_invalidate(spendtx)
         spendtx.rehash()
diff --git a/test/functional/feature_csv_activation.py b/test/functional/feature_csv_activation.py
index 56d2ac463d..2d17c3d8c4 100755
--- a/test/functional/feature_csv_activation.py
+++ b/test/functional/feature_csv_activation.py
@@ -47,7 +47,7 @@ from itertools import product
 from io import BytesIO
 import time
 
-from test_framework.blocktools import create_coinbase, create_block
+from test_framework.blocktools import create_coinbase, create_block, create_transaction
 from test_framework.messages import ToHex, CTransaction
 from test_framework.mininode import P2PDataStore
 from test_framework.script import (
@@ -85,15 +85,6 @@ def relative_locktime(sdf, srhb, stf, srlb):
 def all_rlt_txs(txs):
     return [tx['tx'] for tx in txs]
 
-def create_transaction(node, txid, to_address, amount):
-    inputs = [{"txid": txid, "vout": 0}]
-    outputs = {to_address: amount}
-    rawtx = node.createrawtransaction(inputs, outputs)
-    tx = CTransaction()
-    f = BytesIO(hex_str_to_bytes(rawtx))
-    tx.deserialize(f)
-    return tx
-
 def sign_transaction(node, unsignedtx):
     rawtx = ToHex(unsignedtx)
     signresult = node.signrawtransactionwithwallet(rawtx)
diff --git a/test/functional/feature_dersig.py b/test/functional/feature_dersig.py
index 5b46b4d4b4..b53e742681 100755
--- a/test/functional/feature_dersig.py
+++ b/test/functional/feature_dersig.py
@@ -10,9 +10,8 @@ Test that the DERSIG soft-fork activates at (regtest) height 1251.
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import *
 from test_framework.mininode import *
-from test_framework.blocktools import create_coinbase, create_block
+from test_framework.blocktools import create_coinbase, create_block, create_transaction
 from test_framework.script import CScript
-from io import BytesIO
 
 DERSIG_HEIGHT = 1251
 
@@ -37,15 +36,6 @@ def unDERify(tx):
             newscript.append(i)
     tx.vin[0].scriptSig = CScript(newscript)
 
-def create_transaction(node, coinbase, to_address, amount):
-    from_txid = node.getblock(coinbase)['tx'][0]
-    inputs = [{ "txid" : from_txid, "vout" : 0}]
-    outputs = { to_address : amount }
-    rawtx = node.createrawtransaction(inputs, outputs)
-    signresult = node.signrawtransactionwithwallet(rawtx)
-    tx = CTransaction()
-    tx.deserialize(BytesIO(hex_str_to_bytes(signresult['hex'])))
-    return tx
 
 
 class BIP66Test(BitcoinTestFramework):
@@ -58,12 +48,12 @@ class BIP66Test(BitcoinTestFramework):
         self.nodes[0].add_p2p_connection(P2PInterface())
 
         self.log.info("Mining %d blocks", DERSIG_HEIGHT - 2)
-        self.coinbase_blocks = self.nodes[0].generate(DERSIG_HEIGHT - 2)
+        self.coinbase_txids = [self.nodes[0].getblock(b)['tx'][0] for b in self.nodes[0].generate(DERSIG_HEIGHT - 2)]
         self.nodeaddress = self.nodes[0].getnewaddress()
 
         self.log.info("Test that a transaction with non-DER signature can still appear in a block")
 
-        spendtx = create_transaction(self.nodes[0], self.coinbase_blocks[0],
+        spendtx = create_transaction(self.nodes[0], self.coinbase_txids[0],
                 self.nodeaddress, 1.0)
         unDERify(spendtx)
         spendtx.rehash()
@@ -100,7 +90,7 @@ class BIP66Test(BitcoinTestFramework):
         self.log.info("Test that transactions with non-DER signatures cannot appear in a block")
         block.nVersion = 3
 
-        spendtx = create_transaction(self.nodes[0], self.coinbase_blocks[1],
+        spendtx = create_transaction(self.nodes[0], self.coinbase_txids[1],
                 self.nodeaddress, 1.0)
         unDERify(spendtx)
         spendtx.rehash()
@@ -138,7 +128,7 @@ class BIP66Test(BitcoinTestFramework):
 
         self.log.info("Test that a version 3 block with a DERSIG-compliant transaction is accepted")
         block.vtx[1] = create_transaction(self.nodes[0],
-                self.coinbase_blocks[1], self.nodeaddress, 1.0)
+                self.coinbase_txids[1], self.nodeaddress, 1.0)
         block.hashMerkleRoot = block.calc_merkle_root()
         block.rehash()
         block.solve()
diff --git a/test/functional/feature_nulldummy.py b/test/functional/feature_nulldummy.py
index bd41913e0d..21255c89c8 100755
--- a/test/functional/feature_nulldummy.py
+++ b/test/functional/feature_nulldummy.py
@@ -16,9 +16,8 @@ Generate 427 more blocks.
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import *
 from test_framework.messages import CTransaction
-from test_framework.blocktools import create_coinbase, create_block, add_witness_commitment
+from test_framework.blocktools import create_coinbase, create_block, create_transaction, add_witness_commitment
 from test_framework.script import CScript
-from io import BytesIO
 import time
 
 NULLDUMMY_ERROR = "non-mandatory-script-verify-flag (Dummy CHECKMULTISIG argument must be zero) (code 64)"
@@ -61,16 +60,16 @@ class NULLDUMMYTest(BitcoinTestFramework):
         self.lastblocktime = int(time.time()) + 429
 
         self.log.info("Test 1: NULLDUMMY compliant base transactions should be accepted to mempool and mined before activation [430]")
-        test1txs = [self.create_transaction(self.nodes[0], coinbase_txid[0], self.ms_address, 49)]
+        test1txs = [create_transaction(self.nodes[0], coinbase_txid[0], self.ms_address, 49)]
         txid1 = self.nodes[0].sendrawtransaction(bytes_to_hex_str(test1txs[0].serialize_with_witness()), True)
-        test1txs.append(self.create_transaction(self.nodes[0], txid1, self.ms_address, 48))
+        test1txs.append(create_transaction(self.nodes[0], txid1, self.ms_address, 48))
         txid2 = self.nodes[0].sendrawtransaction(bytes_to_hex_str(test1txs[1].serialize_with_witness()), True)
-        test1txs.append(self.create_transaction(self.nodes[0], coinbase_txid[1], self.wit_ms_address, 49))
+        test1txs.append(create_transaction(self.nodes[0], coinbase_txid[1], self.wit_ms_address, 49))
         txid3 = self.nodes[0].sendrawtransaction(bytes_to_hex_str(test1txs[2].serialize_with_witness()), True)
         self.block_submit(self.nodes[0], test1txs, False, True)
 
         self.log.info("Test 2: Non-NULLDUMMY base multisig transaction should not be accepted to mempool before activation")
-        test2tx = self.create_transaction(self.nodes[0], txid2, self.ms_address, 47)
+        test2tx = create_transaction(self.nodes[0], txid2, self.ms_address, 47)
         trueDummy(test2tx)
         assert_raises_rpc_error(-26, NULLDUMMY_ERROR, self.nodes[0].sendrawtransaction, bytes_to_hex_str(test2tx.serialize_with_witness()), True)
 
@@ -78,14 +77,14 @@ class NULLDUMMYTest(BitcoinTestFramework):
         self.block_submit(self.nodes[0], [test2tx], False, True)
 
         self.log.info("Test 4: Non-NULLDUMMY base multisig transaction is invalid after activation")
-        test4tx = self.create_transaction(self.nodes[0], test2tx.hash, self.address, 46)
+        test4tx = create_transaction(self.nodes[0], test2tx.hash, self.address, 46)
         test6txs=[CTransaction(test4tx)]
         trueDummy(test4tx)
         assert_raises_rpc_error(-26, NULLDUMMY_ERROR, self.nodes[0].sendrawtransaction, bytes_to_hex_str(test4tx.serialize_with_witness()), True)
         self.block_submit(self.nodes[0], [test4tx])
 
         self.log.info("Test 5: Non-NULLDUMMY P2WSH multisig transaction invalid after activation")
-        test5tx = self.create_transaction(self.nodes[0], txid3, self.wit_address, 48)
+        test5tx = create_transaction(self.nodes[0], txid3, self.wit_address, 48)
         test6txs.append(CTransaction(test5tx))
         test5tx.wit.vtxinwit[0].scriptWitness.stack[0] = b'\x01'
         assert_raises_rpc_error(-26, NULLDUMMY_ERROR, self.nodes[0].sendrawtransaction, bytes_to_hex_str(test5tx.serialize_with_witness()), True)
@@ -97,17 +96,6 @@ class NULLDUMMYTest(BitcoinTestFramework):
         self.block_submit(self.nodes[0], test6txs, True, True)
 
 
-    def create_transaction(self, node, txid, to_address, amount):
-        inputs = [{ "txid" : txid, "vout" : 0}]
-        outputs = { to_address : amount }
-        rawtx = node.createrawtransaction(inputs, outputs)
-        signresult = node.signrawtransactionwithwallet(rawtx)
-        tx = CTransaction()
-        f = BytesIO(hex_str_to_bytes(signresult['hex']))
-        tx.deserialize(f)
-        return tx
-
-
     def block_submit(self, node, txs, witness = False, accept = False):
         block = create_block(self.tip, create_coinbase(self.lastblockheight + 1), self.lastblocktime + 1)
         block.nVersion = 4
diff --git a/test/functional/mempool_reorg.py b/test/functional/mempool_reorg.py
index fc4f6d6a52..afacd69d54 100755
--- a/test/functional/mempool_reorg.py
+++ b/test/functional/mempool_reorg.py
@@ -9,6 +9,7 @@ that spend (directly or indirectly) coinbase transactions.
 """
 
 from test_framework.test_framework import BitcoinTestFramework
+from test_framework.blocktools import create_raw_transaction
 from test_framework.util import *
 
 # Create one-input, one-output, no-fee transaction:
@@ -39,9 +40,9 @@ class MempoolCoinbaseTest(BitcoinTestFramework):
         # and make sure the mempool code behaves correctly.
         b = [ self.nodes[0].getblockhash(n) for n in range(101, 105) ]
         coinbase_txids = [ self.nodes[0].getblock(h)['tx'][0] for h in b ]
-        spend_101_raw = create_tx(self.nodes[0], coinbase_txids[1], node1_address, 49.99)
-        spend_102_raw = create_tx(self.nodes[0], coinbase_txids[2], node0_address, 49.99)
-        spend_103_raw = create_tx(self.nodes[0], coinbase_txids[3], node0_address, 49.99)
+        spend_101_raw = create_raw_transaction(self.nodes[0], coinbase_txids[1], node1_address, 49.99)
+        spend_102_raw = create_raw_transaction(self.nodes[0], coinbase_txids[2], node0_address, 49.99)
+        spend_103_raw = create_raw_transaction(self.nodes[0], coinbase_txids[3], node0_address, 49.99)
 
         # Create a transaction which is time-locked to two blocks in the future
         timelock_tx = self.nodes[0].createrawtransaction([{"txid": coinbase_txids[0], "vout": 0}], {node0_address: 49.99})
@@ -60,8 +61,8 @@ class MempoolCoinbaseTest(BitcoinTestFramework):
         assert_raises_rpc_error(-26,'non-final', self.nodes[0].sendrawtransaction, timelock_tx)
 
         # Create 102_1 and 103_1:
-        spend_102_1_raw = create_tx(self.nodes[0], spend_102_id, node1_address, 49.98)
-        spend_103_1_raw = create_tx(self.nodes[0], spend_103_id, node1_address, 49.98)
+        spend_102_1_raw = create_raw_transaction(self.nodes[0], spend_102_id, node1_address, 49.98)
+        spend_103_1_raw = create_raw_transaction(self.nodes[0], spend_103_id, node1_address, 49.98)
 
         # Broadcast and mine 103_1:
         spend_103_1_id = self.nodes[0].sendrawtransaction(spend_103_1_raw)
diff --git a/test/functional/mempool_resurrect.py b/test/functional/mempool_resurrect.py
index 1c8028dd74..3625e011eb 100755
--- a/test/functional/mempool_resurrect.py
+++ b/test/functional/mempool_resurrect.py
@@ -5,6 +5,7 @@
 """Test resurrection of mined transactions when the blockchain is re-organized."""
 
 from test_framework.test_framework import BitcoinTestFramework
+from test_framework.blocktools import create_raw_transaction
 from test_framework.util import *
 
 # Create one-input, one-output, no-fee transaction:
@@ -27,13 +28,13 @@ class MempoolCoinbaseTest(BitcoinTestFramework):
 
         b = [ self.nodes[0].getblockhash(n) for n in range(1, 4) ]
         coinbase_txids = [ self.nodes[0].getblock(h)['tx'][0] for h in b ]
-        spends1_raw = [ create_tx(self.nodes[0], txid, node0_address, 49.99) for txid in coinbase_txids ]
+        spends1_raw = [ create_raw_transaction(self.nodes[0], txid, node0_address, 49.99) for txid in coinbase_txids ]
         spends1_id = [ self.nodes[0].sendrawtransaction(tx) for tx in spends1_raw ]
 
         blocks = []
         blocks.extend(self.nodes[0].generate(1))
 
-        spends2_raw = [ create_tx(self.nodes[0], txid, node0_address, 49.98) for txid in spends1_id ]
+        spends2_raw = [ create_raw_transaction(self.nodes[0], txid, node0_address, 49.98) for txid in spends1_id ]
         spends2_id = [ self.nodes[0].sendrawtransaction(tx) for tx in spends2_raw ]
 
         blocks.extend(self.nodes[0].generate(1))
diff --git a/test/functional/mempool_spend_coinbase.py b/test/functional/mempool_spend_coinbase.py
index fb3c01a9de..74a3634a6c 100755
--- a/test/functional/mempool_spend_coinbase.py
+++ b/test/functional/mempool_spend_coinbase.py
@@ -13,6 +13,7 @@ but less mature coinbase spends are NOT.
 """
 
 from test_framework.test_framework import BitcoinTestFramework
+from test_framework.blocktools import create_raw_transaction
 from test_framework.util import *
 
 # Create one-input, one-output, no-fee transaction:
@@ -31,7 +32,7 @@ class MempoolSpendCoinbaseTest(BitcoinTestFramework):
         # is too immature to spend.
         b = [ self.nodes[0].getblockhash(n) for n in range(101, 103) ]
         coinbase_txids = [ self.nodes[0].getblock(h)['tx'][0] for h in b ]
-        spends_raw = [ create_tx(self.nodes[0], txid, node0_address, 49.99) for txid in coinbase_txids ]
+        spends_raw = [ create_raw_transaction(self.nodes[0], txid, node0_address, 49.99) for txid in coinbase_txids ]
 
         spend_101_id = self.nodes[0].sendrawtransaction(spends_raw[0])
 
diff --git a/test/functional/p2p_invalid_block.py b/test/functional/p2p_invalid_block.py
index b14270cb96..e910bedd09 100755
--- a/test/functional/p2p_invalid_block.py
+++ b/test/functional/p2p_invalid_block.py
@@ -12,7 +12,7 @@ re-requested.
 """
 import copy
 
-from test_framework.blocktools import create_block, create_coinbase, create_transaction
+from test_framework.blocktools import create_block, create_coinbase, create_tx_with_script
 from test_framework.messages import COIN
 from test_framework.mininode import P2PDataStore
 from test_framework.test_framework import BitcoinTestFramework
@@ -63,8 +63,8 @@ class InvalidBlockRequestTest(BitcoinTestFramework):
         block_time += 1
 
         # b'0x51' is OP_TRUE
-        tx1 = create_transaction(block1.vtx[0], 0, b'\x51', 50 * COIN)
-        tx2 = create_transaction(tx1, 0, b'\x51', 50 * COIN)
+        tx1 = create_tx_with_script(block1.vtx[0], 0, script_sig=b'\x51', amount=50 * COIN)
+        tx2 = create_tx_with_script(tx1, 0, script_sig=b'\x51', amount=50 * COIN)
 
         block2.vtx.extend([tx1, tx2])
         block2.hashMerkleRoot = block2.calc_merkle_root()
diff --git a/test/functional/p2p_invalid_tx.py b/test/functional/p2p_invalid_tx.py
index 8236cdf89b..0aa5e21103 100755
--- a/test/functional/p2p_invalid_tx.py
+++ b/test/functional/p2p_invalid_tx.py
@@ -5,7 +5,7 @@
 """Test node responses to invalid transactions.
 
 In this test we connect to one node over p2p, and test tx requests."""
-from test_framework.blocktools import create_block, create_coinbase, create_transaction
+from test_framework.blocktools import create_block, create_coinbase, create_tx_with_script
 from test_framework.messages import (
     COIN,
     COutPoint,
@@ -67,7 +67,7 @@ class InvalidTxRequestTest(BitcoinTestFramework):
         # Transaction will be rejected with code 16 (REJECT_INVALID)
         # and we get disconnected immediately
         self.log.info('Test a transaction that is rejected')
-        tx1 = create_transaction(block1.vtx[0], 0, b'\x64' * 35, 50 * COIN - 12000)
+        tx1 = create_tx_with_script(block1.vtx[0], 0, script_sig=b'\x64' * 35, amount=50 * COIN - 12000)
         node.p2p.send_txs_and_test([tx1], node, success=False, expect_disconnect=True)
 
         # Make two p2p connections to provide the node with orphans
diff --git a/test/functional/p2p_unrequested_blocks.py b/test/functional/p2p_unrequested_blocks.py
index 04a81b0be5..23175bf4a9 100755
--- a/test/functional/p2p_unrequested_blocks.py
+++ b/test/functional/p2p_unrequested_blocks.py
@@ -55,7 +55,7 @@ from test_framework.mininode import *
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import *
 import time
-from test_framework.blocktools import create_block, create_coinbase, create_transaction
+from test_framework.blocktools import create_block, create_coinbase, create_tx_with_script
 
 
 class AcceptBlockTest(BitcoinTestFramework):
@@ -241,7 +241,7 @@ class AcceptBlockTest(BitcoinTestFramework):
         block_290f.solve()
         block_291 = create_block(block_290f.sha256, create_coinbase(291), block_290f.nTime+1)
         # block_291 spends a coinbase below maturity!
-        block_291.vtx.append(create_transaction(block_290f.vtx[0], 0, b"42", 1))
+        block_291.vtx.append(create_tx_with_script(block_290f.vtx[0], 0, script_sig=b"42", amount=1))
         block_291.hashMerkleRoot = block_291.calc_merkle_root()
         block_291.solve()
         block_292 = create_block(block_291.sha256, create_coinbase(292), block_291.nTime+1)
diff --git a/test/functional/test_framework/blocktools.py b/test/functional/test_framework/blocktools.py
index 898da9346a..56f70d9833 100644
--- a/test/functional/test_framework/blocktools.py
+++ b/test/functional/test_framework/blocktools.py
@@ -39,6 +39,7 @@ from .script import (
     hash160,
 )
 from .util import assert_equal
+from io import BytesIO
 
 # From BIP141
 WITNESS_COMMITMENT_HEADER = b"\xaa\x21\xa9\xed"
@@ -117,17 +118,43 @@ def create_coinbase(height, pubkey=None):
     coinbase.calc_sha256()
     return coinbase
 
-def create_transaction(prevtx, n, sig, value, script_pub_key=CScript()):
-    """Create a transaction.
+def create_tx_with_script(prevtx, n, script_sig=b"", amount=1, script_pub_key=CScript()):
+    """Return one-input, one-output transaction object
+       spending the prevtx's n-th output with the given amount.
 
-    If the script_pub_key is not specified, make it anyone-can-spend."""
+       Can optionally pass scriptPubKey and scriptSig, default is anyone-can-spend ouput.
+    """
     tx = CTransaction()
     assert(n < len(prevtx.vout))
-    tx.vin.append(CTxIn(COutPoint(prevtx.sha256, n), sig, 0xffffffff))
-    tx.vout.append(CTxOut(value, script_pub_key))
+    tx.vin.append(CTxIn(COutPoint(prevtx.sha256, n), script_sig, 0xffffffff))
+    tx.vout.append(CTxOut(amount, script_pub_key))
     tx.calc_sha256()
     return tx
 
+def create_transaction(node, txid, to_address, amount):
+    """ Return signed transaction spending the first output of the
+        input txid. Note that the node must be able to sign for the
+        output that is being spent, and the node must not be running
+        multiple wallets.
+    """
+    raw_tx = create_raw_transaction(node, txid, to_address, amount)
+    tx = CTransaction()
+    tx.deserialize(BytesIO(hex_str_to_bytes(raw_tx)))
+    return tx
+
+def create_raw_transaction(node, txid, to_address, amount):
+    """ Return raw signed transaction spending the first output of the
+        input txid. Note that the node must be able to sign for the
+        output that is being spent, and the node must not be running
+        multiple wallets.
+    """
+    inputs = [{"txid": txid, "vout": 0}]
+    outputs = {to_address: amount}
+    rawtx = node.createrawtransaction(inputs, outputs)
+    signresult = node.signrawtransactionwithwallet(rawtx)
+    assert_equal(signresult["complete"], True)
+    return signresult['hex']
+
 def get_legacy_sigopcount_block(block, accurate=True):
     count = 0
     for tx in block.vtx:
diff --git a/test/functional/test_framework/util.py b/test/functional/test_framework/util.py
index be40fa60e5..b355816d8b 100644
--- a/test/functional/test_framework/util.py
+++ b/test/functional/test_framework/util.py
@@ -526,14 +526,6 @@ def gen_return_txouts():
         txouts = txouts + script_pubkey
     return txouts
 
-def create_tx(node, coinbase, to_address, amount):
-    inputs = [{"txid": coinbase, "vout": 0}]
-    outputs = {to_address: amount}
-    rawtx = node.createrawtransaction(inputs, outputs)
-    signresult = node.signrawtransactionwithwallet(rawtx)
-    assert_equal(signresult["complete"], True)
-    return signresult["hex"]
-
 # Create a spend of each passed-in utxo, splicing in "txouts" to each raw
 # transaction to make it large.  See gen_return_txouts() above.
 def create_lots_of_big_transactions(node, txouts, utxos, num, fee):