Add message queue for SSE messages POST endpoint (#459)

tests/server/message_dispatch/conftest.py

@@ -0,0 +1,28 @@
+"""Shared fixtures for message queue tests."""
+
+from collections.abc import AsyncGenerator
+from unittest.mock import patch
+
+import pytest
+
+from mcp.server.message_queue.redis import RedisMessageDispatch
+
+# Set up fakeredis for testing
+try:
+    from fakeredis import aioredis as fake_redis
+except ImportError:
+    pytest.skip(
+        "fakeredis is required for testing Redis functionality", allow_module_level=True
+    )
+
+
+@pytest.fixture
+async def message_dispatch() -> AsyncGenerator[RedisMessageDispatch, None]:
+    """Create a shared Redis message dispatch with a fake Redis client."""
+    with patch("mcp.server.message_queue.redis.redis", fake_redis.FakeRedis):
+        # Shorter TTL for testing
+        message_dispatch = RedisMessageDispatch(session_ttl=5)
+        try:
+            yield message_dispatch
+        finally:
+            await message_dispatch.close()