qa: Add TestNode::assert_debug_log

test/functional/test_framework/test_node.py

@@ -4,6 +4,7 @@
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 """Class for bitcoind node under test"""
 
+import contextlib
 import decimal
 import errno
 from enum import Enum
@@ -229,6 +230,23 @@ class TestNode():
     def wait_until_stopped(self, timeout=BITCOIND_PROC_WAIT_TIMEOUT):
         wait_until(self.is_node_stopped, timeout=timeout)
 
+    @contextlib.contextmanager
+    def assert_debug_log(self, expected_msgs):
+        debug_log = os.path.join(self.datadir, 'regtest', 'debug.log')
+        with open(debug_log, encoding='utf-8') as dl:
+            dl.seek(0, 2)
+            prev_size = dl.tell()
+        try:
+            yield
+        finally:
+            with open(debug_log, encoding='utf-8') as dl:
+                dl.seek(prev_size)
+                log = dl.read()
+            print_log = " - " + "\n - ".join(log.splitlines())
+            for expected_msg in expected_msgs:
+                if re.search(re.escape(expected_msg), log, flags=re.MULTILINE) is None:
+                    self._raise_assertion_error('Expected message "{}" does not partially match log:\n\n{}\n\n'.format(expected_msg, print_log))
+
     def assert_start_raises_init_error(self, extra_args=None, expected_msg=None, match=ErrorMatch.FULL_TEXT, *args, **kwargs):
         """Attempt to start the node and expect it to raise an error.