Hermes-agent

tests/tools/test_mcp_structured_content.py

@@ -0,0 +1,143 @@
+"""Tests for MCP tool structuredContent preservation."""
+
+import asyncio
+import json
+from types import SimpleNamespace
+from unittest.mock import AsyncMock, MagicMock, patch
+
+import pytest
+
+from tools import mcp_tool
+
+
+class _FakeContentBlock:
+    """Minimal content block with .text and .type attributes."""
+
+    def __init__(self, text: str, block_type: str = "text"):
+        self.text = text
+        self.type = block_type
+
+
+class _FakeCallToolResult:
+    """Minimal CallToolResult stand-in.
+
+    Uses camelCase ``structuredContent`` / ``isError`` to match the real
+    MCP SDK Pydantic model (``mcp.types.CallToolResult``).
+    """
+
+    def __init__(self, content, is_error=False, structuredContent=None):
+        self.content = content
+        self.isError = is_error
+        self.structuredContent = structuredContent
+
+
+def _fake_run_on_mcp_loop(coro_or_factory, timeout=30):
+    coro = coro_or_factory() if callable(coro_or_factory) else coro_or_factory
+    """Run an MCP coroutine directly in a fresh event loop."""
+    loop = asyncio.new_event_loop()
+    try:
+        # `_rpc_lock` must be created inside the loop that awaits it, or asyncio
+        # raises "attached to a different loop". Build it here and attach it to
+        # whatever fake server is currently registered under _servers.
+        async def _install_lock_and_run():
+            for srv in list(mcp_tool._servers.values()):
+                if getattr(srv, "_rpc_lock", None) is None:
+                    srv._rpc_lock = asyncio.Lock()
+            return await coro
+        return loop.run_until_complete(_install_lock_and_run())
+    finally:
+        loop.close()
+
+
+@pytest.fixture
+def _patch_mcp_server():
+    """Patch _servers and the MCP event loop so _make_tool_handler can run."""
+    fake_session = MagicMock()
+    # `_rpc_lock` is acquired by _make_tool_handler's call path (mcp_tool.py
+    # ~L2008) to serialize JSON-RPC against the server — build it inside the
+    # fresh loop that _fake_run_on_mcp_loop spins up, not at fixture import.
+    fake_server = SimpleNamespace(session=fake_session, _rpc_lock=None)
+    with patch.dict(mcp_tool._servers, {"test-server": fake_server}), \
+         patch("tools.mcp_tool._run_on_mcp_loop", side_effect=_fake_run_on_mcp_loop):
+        yield fake_session
+
+
+class TestStructuredContentPreservation:
+    """Ensure structuredContent from CallToolResult is forwarded."""
+
+    def test_text_only_result(self, _patch_mcp_server):
+        """When no structuredContent, result is text-only (existing behaviour)."""
+        session = _patch_mcp_server
+        session.call_tool = AsyncMock(
+            return_value=_FakeCallToolResult(
+                content=[_FakeContentBlock("hello")],
+            )
+        )
+        handler = mcp_tool._make_tool_handler("test-server", "my-tool", 30.0)
+        raw = handler({})
+        data = json.loads(raw)
+        assert data == {"result": "hello"}
+
+    def test_both_content_and_structured(self, _patch_mcp_server):
+        """When both content and structuredContent are present, combine them."""
+        session = _patch_mcp_server
+        payload = {"value": "secret-123", "revealed": True}
+        session.call_tool = AsyncMock(
+            return_value=_FakeCallToolResult(
+                content=[_FakeContentBlock("OK")],
+                structuredContent=payload,
+            )
+        )
+        handler = mcp_tool._make_tool_handler("test-server", "my-tool", 30.0)
+        raw = handler({})
+        data = json.loads(raw)
+        # content is the primary result, structuredContent is supplementary
+        assert data["result"] == "OK"
+        assert data["structuredContent"] == payload
+
+    def test_both_content_and_structured_desktop_commander(self, _patch_mcp_server):
+        """Real-world case: Desktop Commander returns file text in content,
+        metadata in structuredContent.  Agent must see file contents."""
+        session = _patch_mcp_server
+        file_text = "import os\nprint('hello')\n"
+        metadata = {"fileName": "main.py", "filePath": "/tmp/main.py", "fileType": "python"}
+        session.call_tool = AsyncMock(
+            return_value=_FakeCallToolResult(
+                content=[_FakeContentBlock(file_text)],
+                structuredContent=metadata,
+            )
+        )
+        handler = mcp_tool._make_tool_handler("test-server", "my-tool", 30.0)
+        raw = handler({})
+        data = json.loads(raw)
+        assert data["result"] == file_text
+        assert data["structuredContent"] == metadata
+
+    def test_structured_content_none_falls_back_to_text(self, _patch_mcp_server):
+        """When structuredContent is explicitly None, fall back to text."""
+        session = _patch_mcp_server
+        session.call_tool = AsyncMock(
+            return_value=_FakeCallToolResult(
+                content=[_FakeContentBlock("done")],
+                structuredContent=None,
+            )
+        )
+        handler = mcp_tool._make_tool_handler("test-server", "my-tool", 30.0)
+        raw = handler({})
+        data = json.loads(raw)
+        assert data == {"result": "done"}
+
+    def test_empty_text_with_structured_content(self, _patch_mcp_server):
+        """When content blocks are empty but structuredContent exists."""
+        session = _patch_mcp_server
+        payload = {"status": "ok", "data": [1, 2, 3]}
+        session.call_tool = AsyncMock(
+            return_value=_FakeCallToolResult(
+                content=[],
+                structuredContent=payload,
+            )
+        )
+        handler = mcp_tool._make_tool_handler("test-server", "my-tool", 30.0)
+        raw = handler({})
+        data = json.loads(raw)
+        assert data["result"] == payload