test: add node.chain_path and node.debug_log_path

To allow easier access to the node's datadir and debug logs.

test/functional/test_framework/test_node.py

@@ -20,6 +20,7 @@ import urllib.parse
 import collections
 import shlex
 import sys
+from pathlib import Path
 
 from .authproxy import JSONRPCException
 from .descriptors import descsum_create
@@ -368,13 +369,20 @@ class TestNode():
     def wait_until_stopped(self, timeout=BITCOIND_PROC_WAIT_TIMEOUT):
         wait_until_helper(self.is_node_stopped, timeout=timeout, timeout_factor=self.timeout_factor)
 
+    @property
+    def chain_path(self) -> Path:
+        return Path(self.datadir) / self.chain
+
+    @property
+    def debug_log_path(self) -> Path:
+        return self.chain_path / 'debug.log'
+
     @contextlib.contextmanager
     def assert_debug_log(self, expected_msgs, unexpected_msgs=None, timeout=2):
         if unexpected_msgs is None:
             unexpected_msgs = []
         time_end = time.time() + timeout * self.timeout_factor
-        debug_log = os.path.join(self.datadir, self.chain, 'debug.log')
+        with open(self.debug_log_path, encoding='utf-8') as dl:
-        with open(debug_log, encoding='utf-8') as dl:
             dl.seek(0, 2)
             prev_size = dl.tell()
 
@@ -382,7 +390,7 @@ class TestNode():
 
         while True:
             found = True
-            with open(debug_log, encoding='utf-8') as dl:
+            with open(self.debug_log_path, encoding='utf-8') as dl:
                 dl.seek(prev_size)
                 log = dl.read()
             print_log = " - " + "\n - ".join(log.splitlines())