qa: Add feature_framework_stop_node.py

test/functional/feature_framework_stop_node.py

@@ -0,0 +1,49 @@
+#!/usr/bin/env python3
+# Copyright (c) 2024-present The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+"""
+Verify that when a node process fails due to a startup error, we can still call
+TestNode.stop_node() without triggering knock-on errors.
+"""
+
+from test_framework.test_node import (
+    FailedToStartError,
+    TestNode,
+)
+from test_framework.util import (
+    assert_raises_message,
+)
+from test_framework.test_framework import BitcoinTestFramework
+
+class FeatureFrameworkStopNode(BitcoinTestFramework):
+    def set_test_params(self):
+        self.num_nodes = 1
+
+    # Overridden to avoid syncing non-started nodes.
+    def setup_network(self):
+        self.setup_nodes()
+
+    # Overridden to avoid starting nodes before run_test.
+    def setup_nodes(self):
+        self.add_nodes(self.num_nodes, self.extra_args)
+
+    def run_test(self):
+        # Don't use the full assert_start_raises_init_error() here, as we want
+        # to clean state ourselves after wait_for_rpc_connection() fails.
+        invalid_arg_error = "Error: Error parsing command line arguments: Invalid parameter -nonexistentarg"
+        assert_raises_message(
+            exc=FailedToStartError,
+            message="[node 0] bitcoind exited with status 1 during initialization. " + invalid_arg_error,
+            fun=BitcoinTestFramework.start_node,
+            self=self,
+            i=0,
+            extra_args=['-nonexistentarg'], # Intentionally trigger startup failure.
+        )
+        assert self.nodes[0].running, \
+            "The process should still be flagged as running before calling stop_node()"
+        self.log.info("One WARNING expected - Explicitly stopping the node to verify it completes cleanly during the test")
+        self.nodes[0].stop_node(expected_stderr=invalid_arg_error, avoid_exceptions=True)
+
+if __name__ == '__main__':
+    FeatureFrameworkStopNode(__file__).main()

test/functional/test_runner.py

@@ -406,6 +406,7 @@
     'feature_help.py',
     'feature_framework_rpc_failure.py',
     'feature_framework_rpc_failure_details.py',
+    'feature_framework_stop_node.py',
     'feature_shutdown.py',
     'wallet_migration.py',
     'p2p_ibd_txrelay.py',