|
| 1 | +from contextlib import asynccontextmanager |
| 2 | +from unittest.mock import patch |
| 3 | + |
| 4 | +import pytest |
| 5 | + |
| 6 | +import mcp.shared.memory |
| 7 | +from mcp.shared.message import SessionMessage |
| 8 | +from mcp.types import ( |
| 9 | + JSONRPCNotification, |
| 10 | + JSONRPCRequest, |
| 11 | +) |
| 12 | + |
| 13 | + |
| 14 | +class SpyMemoryObjectSendStream: |
| 15 | + def __init__(self, original_stream): |
| 16 | + self.original_stream = original_stream |
| 17 | + self.sent_messages: list[SessionMessage] = [] |
| 18 | + |
| 19 | + async def send(self, message): |
| 20 | + self.sent_messages.append(message) |
| 21 | + await self.original_stream.send(message) |
| 22 | + |
| 23 | + async def aclose(self): |
| 24 | + await self.original_stream.aclose() |
| 25 | + |
| 26 | + async def __aenter__(self): |
| 27 | + return self |
| 28 | + |
| 29 | + async def __aexit__(self, *args): |
| 30 | + await self.aclose() |
| 31 | + |
| 32 | + |
| 33 | +class StreamSpyCollection: |
| 34 | + def __init__( |
| 35 | + self, |
| 36 | + client_spy: SpyMemoryObjectSendStream, |
| 37 | + server_spy: SpyMemoryObjectSendStream, |
| 38 | + ): |
| 39 | + self.client = client_spy |
| 40 | + self.server = server_spy |
| 41 | + |
| 42 | + def clear(self) -> None: |
| 43 | + """Clear all captured messages.""" |
| 44 | + self.client.sent_messages.clear() |
| 45 | + self.server.sent_messages.clear() |
| 46 | + |
| 47 | + def get_client_requests(self, method: str | None = None) -> list[JSONRPCRequest]: |
| 48 | + """Get client-sent requests, optionally filtered by method.""" |
| 49 | + return [ |
| 50 | + req.message.root |
| 51 | + for req in self.client.sent_messages |
| 52 | + if isinstance(req.message.root, JSONRPCRequest) |
| 53 | + and (method is None or req.message.root.method == method) |
| 54 | + ] |
| 55 | + |
| 56 | + def get_server_requests(self, method: str | None = None) -> list[JSONRPCRequest]: |
| 57 | + """Get server-sent requests, optionally filtered by method.""" |
| 58 | + return [ |
| 59 | + req.message.root |
| 60 | + for req in self.server.sent_messages |
| 61 | + if isinstance(req.message.root, JSONRPCRequest) |
| 62 | + and (method is None or req.message.root.method == method) |
| 63 | + ] |
| 64 | + |
| 65 | + def get_client_notifications( |
| 66 | + self, method: str | None = None |
| 67 | + ) -> list[JSONRPCNotification]: |
| 68 | + """Get client-sent notifications, optionally filtered by method.""" |
| 69 | + return [ |
| 70 | + notif.message.root |
| 71 | + for notif in self.client.sent_messages |
| 72 | + if isinstance(notif.message.root, JSONRPCNotification) |
| 73 | + and (method is None or notif.message.root.method == method) |
| 74 | + ] |
| 75 | + |
| 76 | + def get_server_notifications( |
| 77 | + self, method: str | None = None |
| 78 | + ) -> list[JSONRPCNotification]: |
| 79 | + """Get server-sent notifications, optionally filtered by method.""" |
| 80 | + return [ |
| 81 | + notif.message.root |
| 82 | + for notif in self.server.sent_messages |
| 83 | + if isinstance(notif.message.root, JSONRPCNotification) |
| 84 | + and (method is None or notif.message.root.method == method) |
| 85 | + ] |
| 86 | + |
| 87 | + |
| 88 | +@pytest.fixture |
| 89 | +def stream_spy(): |
| 90 | + """Fixture that provides spies for both client and server write streams. |
| 91 | +
|
| 92 | + Example usage: |
| 93 | + async def test_something(stream_spy): |
| 94 | + # ... set up server and client ... |
| 95 | +
|
| 96 | + spies = stream_spy() |
| 97 | +
|
| 98 | + # Run some operation that sends messages |
| 99 | + await client.some_operation() |
| 100 | +
|
| 101 | + # Check the messages |
| 102 | + requests = spies.get_client_requests(method="some/method") |
| 103 | + assert len(requests) == 1 |
| 104 | +
|
| 105 | + # Clear for the next operation |
| 106 | + spies.clear() |
| 107 | + """ |
| 108 | + client_spy = None |
| 109 | + server_spy = None |
| 110 | + |
| 111 | + # Store references to our spy objects |
| 112 | + def capture_spies(c_spy, s_spy): |
| 113 | + nonlocal client_spy, server_spy |
| 114 | + client_spy = c_spy |
| 115 | + server_spy = s_spy |
| 116 | + |
| 117 | + # Create patched version of stream creation |
| 118 | + original_create_streams = mcp.shared.memory.create_client_server_memory_streams |
| 119 | + |
| 120 | + @asynccontextmanager |
| 121 | + async def patched_create_streams(): |
| 122 | + async with original_create_streams() as (client_streams, server_streams): |
| 123 | + client_read, client_write = client_streams |
| 124 | + server_read, server_write = server_streams |
| 125 | + |
| 126 | + # Create spy wrappers |
| 127 | + spy_client_write = SpyMemoryObjectSendStream(client_write) |
| 128 | + spy_server_write = SpyMemoryObjectSendStream(server_write) |
| 129 | + |
| 130 | + # Capture references for the test to use |
| 131 | + capture_spies(spy_client_write, spy_server_write) |
| 132 | + |
| 133 | + yield (client_read, spy_client_write), (server_read, spy_server_write) |
| 134 | + |
| 135 | + # Apply the patch for the duration of the test |
| 136 | + with patch( |
| 137 | + "mcp.shared.memory.create_client_server_memory_streams", patched_create_streams |
| 138 | + ): |
| 139 | + # Return a collection with helper methods |
| 140 | + yield lambda: StreamSpyCollection(client_spy, server_spy) |
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