test: Support disconnect waiting for add_p2p_connection

Adds a new boolean parameter `expect_success` to the
`add_p2p_connection` method. If set, the node under
test doesn't wait for connection to be established
and is useful for testing scenarios when disconnection
is expected.

Without this parameter, intermittent test failures can happen
if the disconnection happens before wait_until for is_connected
is hit inside `add_p2p_connection`.

Co-Authored-By: Sebastian Falbesoner <[email protected]>

Author: stratospher

test/functional/test_framework/test_node.py

@@ -667,7 +667,7 @@ def assert_start_raises_init_error(self, extra_args=None, expected_msg=None, mat
                     assert_msg += "with expected error " + expected_msg
                 self._raise_assertion_error(assert_msg)
 
-    def add_p2p_connection(self, p2p_conn, *, wait_for_verack=True, send_version=True, supports_v2_p2p=None, wait_for_v2_handshake=True, **kwargs):
+    def add_p2p_connection(self, p2p_conn, *, wait_for_verack=True, send_version=True, supports_v2_p2p=None, wait_for_v2_handshake=True, expect_success=True, **kwargs):
         """Add an inbound p2p connection to the node.
 
         This method adds the p2p connection to the self.p2ps list and also
@@ -687,14 +687,15 @@ def add_p2p_connection(self, p2p_conn, *, wait_for_verack=True, send_version=Tru
         if supports_v2_p2p is None:
             supports_v2_p2p = self.use_v2transport
 
-
         p2p_conn.p2p_connected_to_node = True
         if self.use_v2transport:
             kwargs['services'] = kwargs.get('services', P2P_SERVICES) | NODE_P2P_V2
         supports_v2_p2p = self.use_v2transport and supports_v2_p2p
         p2p_conn.peer_connect(**kwargs, send_version=send_version, net=self.chain, timeout_factor=self.timeout_factor, supports_v2_p2p=supports_v2_p2p)()
 
         self.p2ps.append(p2p_conn)
+        if not expect_success:
+            return p2p_conn
         p2p_conn.wait_until(lambda: p2p_conn.is_connected, check_connected=False)
         if supports_v2_p2p and wait_for_v2_handshake:
             p2p_conn.wait_until(lambda: p2p_conn.v2_state.tried_v2_handshake)