Trying to fix tests

Author: strawgate

pydantic_ai_slim/pydantic_ai/toolsets/fastmcp.py

@@ -4,15 +4,9 @@
 from asyncio import Lock
 from contextlib import AsyncExitStack
 from enum import Enum
-from typing import TYPE_CHECKING, Any, Self
+from typing import TYPE_CHECKING, Any
 
-from mcp.types import (
-    AudioContent,
-    ContentBlock,
-    ImageContent,
-    TextContent,
-    Tool as MCPTool,
-)
+from typing_extensions import Self
 
 from pydantic_ai.exceptions import ModelRetry
 from pydantic_ai.mcp import TOOL_SCHEMA_VALIDATOR, messages
@@ -26,6 +20,14 @@
     from fastmcp.exceptions import ToolError
     from fastmcp.mcp_config import MCPConfig
     from fastmcp.server.server import FastMCP
+    from mcp.types import (
+        AudioContent,
+        ContentBlock,
+        ImageContent,
+        TextContent,
+        Tool as MCPTool,
+    )
+
 except ImportError as _import_error:
     raise ImportError(
         'Please install the `fastmcp` package to use the FastMCP server, '
@@ -70,6 +72,13 @@ class FastMCPToolset(AbstractToolset[AgentDepsT]):
     def __init__(
         self, fastmcp_client: Client[Any], tool_retries: int = 2, tool_error_behavior: ToolErrorBehavior | None = None
     ):
+        """Build a new FastMCPToolset.
+
+        Args:
+            fastmcp_client: The FastMCP client to use.
+            tool_retries: The number of times to retry a tool call.
+            tool_error_behavior: The behavior to take when a tool error occurs.
+        """
         self._tool_retries = tool_retries
         self._fastmcp_client = fastmcp_client
         self._enter_lock = Lock()
@@ -150,7 +159,7 @@ def from_fastmcp_server(
         async def my_tool(a: int, b: int) -> int:
             return a + b
 
-        toolset = FastMCPToolset.from_fastmcp_server(fastmcp_server=fastmcp_server)
+        FastMCPToolset.from_fastmcp_server(fastmcp_server=fastmcp_server)
         ```
         """
         transport = FastMCPTransport(fastmcp_server)
@@ -168,23 +177,15 @@ def from_mcp_server(
 
         Example:
         ```python
-        from pydantic_ai import Agent
         from pydantic_ai.toolsets.fastmcp import FastMCPToolset
 
         time_mcp_server = {
-            'command': 'uvx',
-            'args': [
-                'mcp-server-time',
-            ]
+            'command': 'uv',
+            'args': ['run', 'mcp-run-python', 'stdio'],
         }
 
-        toolset = FastMCPToolset.from_mcp_server(name='time_server', mcp_server=time_mcp_server)
-        agent = Agent('openai:gpt-4o', toolsets=[toolset])
-        async def main():
-            async with agent:  # (1)!
-                ...
+        FastMCPToolset.from_mcp_server(name='time_server', mcp_server=time_mcp_server)
         ```
-        1. This will start the MCP Server running over stdio.
         """
         mcp_config: MCPConfig = MCPConfig.from_dict(config={name: mcp_server})
 
@@ -198,35 +199,23 @@ def from_mcp_config(
 
         Example:
         ```python
-        from pydantic_ai import Agent
         from pydantic_ai.toolsets.fastmcp import FastMCPToolset
 
         mcp_config = {
             'mcpServers': {
-                'time_server': {
-                    'command': 'uvx',
-                    'args': [
-                        'mcp-server-time',
-                    ]
+                'first_server': {
+                    'command': 'uv',
+                    'args': ['run', 'mcp-run-python', 'stdio'],
                 },
-                'fetch_server': {
-                    'command': 'uvx',
-                    'args': [
-                        'mcp-server-fetch',
-                    ]
+                'second_server': {
+                    'command': 'uv',
+                    'args': ['run', 'mcp-run-python', 'stdio'],
                 }
             }
         }
 
-        fastmcp_toolset = FastMCPToolset.from_mcp_config(mcp_config)
-
-        agent = Agent('openai:gpt-4o', toolsets=[fastmcp_toolset])
-        async def main():
-            async with agent:  # (1)!
-                ...
+        FastMCPToolset.from_mcp_config(mcp_config)
         ```
-
-        1. This will start both MCP Servers running over stdio`.
         """
         transport: MCPConfigTransport = MCPConfigTransport(config=mcp_config)
         fastmcp_client: Client[MCPConfigTransport] = Client[MCPConfigTransport](transport=transport)

pyproject.toml

@@ -89,6 +89,7 @@ dev = [
     "coverage[toml]>=7.10.3",
     "dirty-equals>=0.9.0",
     "duckduckgo-search>=7.0.0",
+    "fastmcp>=2.12.0",
     "inline-snapshot>=0.19.3",
     "pytest>=8.3.3",
     "pytest-examples>=0.0.18",

tests/test_fastmcp.py

@@ -7,7 +7,6 @@
 
 import pytest
 from inline_snapshot import snapshot
-from mcp.types import TextContent
 
 from pydantic_ai._run_context import RunContext
 from pydantic_ai.exceptions import ModelRetry
@@ -26,6 +25,7 @@
     from mcp.types import (
         AudioContent,
         ImageContent,
+        TextContent,
     )
 
     # Import the content mapping functions for testing
@@ -57,11 +57,9 @@ async def another_tool(value: float) -> dict[str, Any]:
         return {'result': 'success', 'value': value, 'doubled': value * 2}
 
     @server.tool()
-    async def error_tool(should_fail: bool = False) -> str:
+    async def error_tool() -> str:
         """A tool that can fail for testing error handling."""
-        if should_fail:
-            raise ValueError('This is a test error')
-        return 'success'
+        raise ValueError('This is a test error')
 
     @server.tool()
     async def binary_tool() -> ImageContent:
@@ -395,7 +393,7 @@ async def test_call_tool_with_error_behavior_raise(
 
             with pytest.raises(ToolError, match='This is a test error'):
                 await fastmcp_toolset.call_tool(
-                    name='error_tool', tool_args={'should_fail': True}, ctx=run_context, tool=error_tool
+                    name='error_tool', tool_args={}, ctx=run_context, tool=error_tool
                 )
 
     async def test_call_tool_with_error_behavior_model_retry(
@@ -411,7 +409,7 @@ async def test_call_tool_with_error_behavior_model_retry(
             error_tool = tools['error_tool']
 
             with pytest.raises(ModelRetry, match='This is a test error'):
-                await toolset.call_tool('error_tool', {'should_fail': True}, run_context, error_tool)
+                await toolset.call_tool('error_tool', {}, run_context, error_tool)
 
 
 class TestFastMCPToolsetFactoryMethods: