Merge bitcoin/bitcoin#24559: test: add test for signet miner script

038d2a607f93a31be76f3a8210a5385996012783 test: add test for signet miner script (Sebastian Falbesoner)
449b96ed97f8b95cae91858dba605b326de1fd45 test: add `is_bitcoin_util_compiled` helper (Sebastian Falbesoner)
dde33eca63347801097e39b8dbed5b9ebbd97278 test: determine path to `bitcoin-util` in test framework (Sebastian Falbesoner)

Pull request description:

  This PR adds a very basic test for the signet miner script (contrib/signet/miner). ~~It was based on #24553 (merged by now) which fixes a bug (and was also the motivation to write this test).~~

  The test roughly follows the steps from https://en.bitcoin.it/wiki/Signet#Custom_Signet, except that the challenge key-pair is created solely with the test framework. Calibration is also skipped, the difficulty is simply set to the first mainnet target `0x1d00ffff` (see also https://bitcoin.stackexchange.com/a/57186).

ACKs for top commit:
  laanwj:
    re-ACK 038d2a607f93a31be76f3a8210a5385996012783

Tree-SHA512: 150698a3c0cda3679661b47688e3b932c9761e777fdd284776b867b485db6a8895960177bd02a53f838a4c9b9bbe6a9beea8d7a5b14825b38e4e43b3177821b3

4 files changed, 80 insertions, 0 deletions

diff --git a/test/config.ini.in b/test/config.ini.in
index d7105c419b..5888ef443b 100644
--- a/test/config.ini.in
+++ b/test/config.ini.in
@@ -19,6 +19,7 @@ RPCAUTH=@abs_top_srcdir@/share/rpcauth/rpcauth.py
 @USE_SQLITE_TRUE@USE_SQLITE=true
 @USE_BDB_TRUE@USE_BDB=true
 @BUILD_BITCOIN_CLI_TRUE@ENABLE_CLI=true
+@BUILD_BITCOIN_UTIL_TRUE@ENABLE_BITCOIN_UTIL=true
 @BUILD_BITCOIN_WALLET_TRUE@ENABLE_WALLET_TOOL=true
 @BUILD_BITCOIND_TRUE@ENABLE_BITCOIND=true
 @ENABLE_FUZZ_TRUE@ENABLE_FUZZ=true
diff --git a/test/functional/test_framework/test_framework.py b/test/functional/test_framework/test_framework.py
index 2fb9ec0942..a39ee003ef 100755
--- a/test/functional/test_framework/test_framework.py
+++ b/test/functional/test_framework/test_framework.py
@@ -244,8 +244,14 @@ class BitcoinTestFramework(metaclass=BitcoinTestMetaClass):
             "src",
             "bitcoin-cli" + config["environment"]["EXEEXT"],
         )
+        fname_bitcoinutil = os.path.join(
+            config["environment"]["BUILDDIR"],
+            "src",
+            "bitcoin-util" + config["environment"]["EXEEXT"],
+        )
         self.options.bitcoind = os.getenv("BITCOIND", default=fname_bitcoind)
         self.options.bitcoincli = os.getenv("BITCOINCLI", default=fname_bitcoincli)
+        self.options.bitcoinutil = os.getenv("BITCOINUTIL", default=fname_bitcoinutil)
 
         os.environ['PATH'] = os.pathsep.join([
             os.path.join(config['environment']['BUILDDIR'], 'src'),
@@ -880,6 +886,11 @@ class BitcoinTestFramework(metaclass=BitcoinTestMetaClass):
         if not self.is_wallet_tool_compiled():
             raise SkipTest("bitcoin-wallet has not been compiled")
 
+    def skip_if_no_bitcoin_util(self):
+        """Skip the running test if bitcoin-util has not been compiled."""
+        if not self.is_bitcoin_util_compiled():
+            raise SkipTest("bitcoin-util has not been compiled")
+
     def skip_if_no_cli(self):
         """Skip the running test if bitcoin-cli has not been compiled."""
         if not self.is_cli_compiled():
@@ -927,6 +938,10 @@ class BitcoinTestFramework(metaclass=BitcoinTestMetaClass):
         """Checks whether bitcoin-wallet was compiled."""
         return self.config["components"].getboolean("ENABLE_WALLET_TOOL")
 
+    def is_bitcoin_util_compiled(self):
+        """Checks whether bitcoin-util was compiled."""
+        return self.config["components"].getboolean("ENABLE_BITCOIN_UTIL")
+
     def is_zmq_compiled(self):
         """Checks whether the zmq module was compiled."""
         return self.config["components"].getboolean("ENABLE_ZMQ")
diff --git a/test/functional/test_runner.py b/test/functional/test_runner.py
index 1f0f806d91..a3c938ae26 100755
--- a/test/functional/test_runner.py
+++ b/test/functional/test_runner.py
@@ -145,6 +145,8 @@ BASE_SCRIPTS = [
     'wallet_txn_doublespend.py --mineblock',
     'tool_wallet.py --legacy-wallet',
     'tool_wallet.py --descriptors',
+    'tool_signet_miner.py --legacy-wallet',
+    'tool_signet_miner.py --descriptors',
     'wallet_txn_clone.py',
     'wallet_txn_clone.py --segwit',
     'rpc_getchaintips.py',
diff --git a/test/functional/tool_signet_miner.py b/test/functional/tool_signet_miner.py
new file mode 100755
index 0000000000..e6fc9072ab
--- /dev/null
+++ b/test/functional/tool_signet_miner.py
@@ -0,0 +1,62 @@
+#!/usr/bin/env python3
+# Copyright (c) 2022 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+"""Test signet miner tool"""
+
+import os.path
+import subprocess
+import sys
+import time
+
+from test_framework.key import ECKey
+from test_framework.script_util import key_to_p2wpkh_script
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import assert_equal
+from test_framework.wallet_util import bytes_to_wif
+
+
+CHALLENGE_PRIVATE_KEY = (42).to_bytes(32, 'big')
+
+
+class SignetMinerTest(BitcoinTestFramework):
+    def set_test_params(self):
+        self.chain = "signet"
+        self.setup_clean_chain = True
+        self.num_nodes = 1
+
+        # generate and specify signet challenge (simple p2wpkh script)
+        privkey = ECKey()
+        privkey.set(CHALLENGE_PRIVATE_KEY, True)
+        pubkey = privkey.get_pubkey().get_bytes()
+        challenge = key_to_p2wpkh_script(pubkey)
+        self.extra_args = [[f'-signetchallenge={challenge.hex()}']]
+
+    def skip_test_if_missing_module(self):
+        self.skip_if_no_cli()
+        self.skip_if_no_wallet()
+        self.skip_if_no_bitcoin_util()
+
+    def run_test(self):
+        node = self.nodes[0]
+        # import private key needed for signing block
+        node.importprivkey(bytes_to_wif(CHALLENGE_PRIVATE_KEY))
+
+        # generate block with signet miner tool
+        base_dir = self.config["environment"]["SRCDIR"]
+        signet_miner_path = os.path.join(base_dir, "contrib", "signet", "miner")
+        subprocess.run([
+                sys.executable,
+                signet_miner_path,
+                f'--cli={node.cli.binary} -datadir={node.cli.datadir}',
+                'generate',
+                f'--address={node.getnewaddress()}',
+                f'--grind-cmd={self.options.bitcoinutil} grind',
+                '--nbits=1d00ffff',
+                f'--set-block-time={int(time.time())}',
+            ], check=True, stderr=subprocess.STDOUT)
+        assert_equal(node.getblockcount(), 1)
+
+
+if __name__ == "__main__":
+    SignetMinerTest().main()