from typing import cast import pytest from pydantic import AnyUrl from fastmcp.client import Client from fastmcp.client.transports import FastMCPTransport from fastmcp.server.server import FastMCP @pytest.fixture def fastmcp_server(): """Fixture that creates a FastMCP server with tools, resources, and prompts.""" server = FastMCP("TestServer") # Add a tool @server.tool() def greet(name: str) -> str: """Greet someone by name.""" return f"Hello, {name}!" # Add a second tool @server.tool() def add(a: int, b: int) -> int: """Add two numbers together.""" return a + b # Add a resource @server.resource(uri="data://users") async def get_users(): return ["Alice", "Bob", "Charlie"] # Add a resource template @server.resource(uri="data://user/{user_id}") async def get_user(user_id: str): return {"id": user_id, "name": f"User {user_id}", "active": True} # Add a prompt @server.prompt() def welcome(name: str) -> str: return f"Welcome to FastMCP, {name}!" return server async def test_list_tools(fastmcp_server): """Test listing tools with InMemoryClient.""" client = Client(transport=FastMCPTransport(fastmcp_server)) async with client: result = await client.list_tools() # Check that our tools are available assert len(result) == 2 assert set(tool.name for tool in result) == {"greet", "add"} async def test_call_tool(fastmcp_server): """Test calling a tool with InMemoryClient.""" client = Client(transport=FastMCPTransport(fastmcp_server)) async with client: result = await client.call_tool("greet", {"name": "World"}) # The result content should contain our greeting content_str = str(result[0]) assert "Hello, World!" in content_str async def test_list_resources(fastmcp_server): """Test listing resources with InMemoryClient.""" client = Client(transport=FastMCPTransport(fastmcp_server)) async with client: result = await client.list_resources() # Check that our resource is available assert len(result) == 1 assert str(result[0].uri) == "data://users" async def test_list_prompts(fastmcp_server): """Test listing prompts with InMemoryClient.""" client = Client(transport=FastMCPTransport(fastmcp_server)) async with client: result = await client.list_prompts() # Check that our prompt is available assert len(result) == 1 assert result[0].name == "welcome" async def test_get_prompt(fastmcp_server): """Test getting a prompt with InMemoryClient.""" client = Client(transport=FastMCPTransport(fastmcp_server)) async with client: result = await client.get_prompt("welcome", {"name": "Developer"}) # The result should contain our welcome message result_str = str(result) assert "Welcome to FastMCP, Developer!" in result_str async def test_read_resource(fastmcp_server): """Test reading a resource with InMemoryClient.""" client = Client(transport=FastMCPTransport(fastmcp_server)) async with client: # Use the URI from the resource we know exists in our server uri = cast( AnyUrl, "data://users" ) # Use cast for type hint only, the URI is valid result = await client.read_resource(uri) # The contents should include our user list contents_str = str(result[0]) assert "Alice" in contents_str assert "Bob" in contents_str assert "Charlie" in contents_str async def test_client_connection(fastmcp_server): """Test that the client connects and disconnects properly.""" client = Client(transport=FastMCPTransport(fastmcp_server)) # Before connection assert not client.is_connected() # During connection async with client: assert client.is_connected() # After connection assert not client.is_connected() async def test_resource_template(fastmcp_server): """Test using a resource template with InMemoryClient.""" client = Client(transport=FastMCPTransport(fastmcp_server)) async with client: # First, list templates result = await client.list_resource_templates() # Check that our template is available assert len(result) == 1 assert "data://user/{user_id}" in result[0].uriTemplate # Now use the template with a specific user_id uri = cast(AnyUrl, "data://user/123") result = await client.read_resource(uri) # Check the content matches what we expect for the provided user_id content_str = str(result[0]) assert '"id": "123"' in content_str assert '"name": "User 123"' in content_str assert '"active": true' in content_str