fastmcp/tests/client/test_client.py
2025-04-15 20:28:14 -04:00

268 lines
8.5 KiB
Python

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
@pytest.fixture
def tagged_resources_server():
"""Fixture that creates a FastMCP server with tagged resources and templates."""
server = FastMCP("TaggedResourcesServer")
# Add a resource with tags
@server.resource(
uri="data://tagged", tags={"test", "metadata"}, description="A tagged resource"
)
async def get_tagged_data():
return {"type": "tagged_data"}
# Add a resource template with tags
@server.resource(
uri="template://{id}",
tags={"template", "parameterized"},
description="A tagged template",
)
async def get_template_data(id: str):
return {"id": id, "type": "template_data"}
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
async def test_mcp_resource_generation(fastmcp_server):
"""Test that resources are properly generated in MCP format."""
client = Client(transport=FastMCPTransport(fastmcp_server))
async with client:
resources = await client.list_resources()
assert len(resources) == 1
resource = resources[0]
# Verify resource has correct MCP format
assert hasattr(resource, "uri")
assert hasattr(resource, "name")
assert hasattr(resource, "description")
assert str(resource.uri) == "data://users"
async def test_mcp_template_generation(fastmcp_server):
"""Test that templates are properly generated in MCP format."""
client = Client(transport=FastMCPTransport(fastmcp_server))
async with client:
templates = await client.list_resource_templates()
assert len(templates) == 1
template = templates[0]
# Verify template has correct MCP format
assert hasattr(template, "uriTemplate")
assert hasattr(template, "name")
assert hasattr(template, "description")
assert "data://user/{user_id}" in template.uriTemplate
async def test_template_access_via_client(fastmcp_server):
"""Test that templates can be accessed through a client."""
client = Client(transport=FastMCPTransport(fastmcp_server))
async with client:
# Verify template works correctly when accessed
uri = cast(AnyUrl, "data://user/456")
result = await client.read_resource(uri)
content_str = str(result[0])
assert '"id": "456"' in content_str
async def test_tagged_resource_metadata(tagged_resources_server):
"""Test that resource metadata is preserved in MCP format."""
client = Client(transport=FastMCPTransport(tagged_resources_server))
async with client:
resources = await client.list_resources()
assert len(resources) == 1
resource = resources[0]
# Verify resource metadata is preserved
assert str(resource.uri) == "data://tagged"
assert resource.description == "A tagged resource"
async def test_tagged_template_metadata(tagged_resources_server):
"""Test that template metadata is preserved in MCP format."""
client = Client(transport=FastMCPTransport(tagged_resources_server))
async with client:
templates = await client.list_resource_templates()
assert len(templates) == 1
template = templates[0]
# Verify template metadata is preserved
assert "template://{id}" in template.uriTemplate
assert template.description == "A tagged template"
async def test_tagged_template_functionality(tagged_resources_server):
"""Test that tagged templates function correctly when accessed."""
client = Client(transport=FastMCPTransport(tagged_resources_server))
async with client:
# Verify template functionality
uri = cast(AnyUrl, "template://123")
result = await client.read_resource(uri)
content_str = str(result[0])
assert '"id": "123"' in content_str
assert '"type": "template_data"' in content_str