fastmcp/tests/resources/test_resource_template.py

666 lines
22 KiB
Python

import json
from urllib.parse import quote
import pytest
from pydantic import BaseModel
from fastmcp import Context
from fastmcp.resources import FunctionResource, ResourceTemplate
from fastmcp.resources.template import match_uri_template
class TestResourceTemplate:
"""Test ResourceTemplate functionality."""
def test_template_creation(self):
"""Test creating a template from a function."""
def my_func(key: str, value: int) -> dict:
return {"key": key, "value": value}
template = ResourceTemplate.from_function(
fn=my_func,
uri_template="test://{key}/{value}",
name="test",
)
assert template.uri_template == "test://{key}/{value}"
assert template.name == "test"
assert template.mime_type == "text/plain" # default
test_input = {"key": "test", "value": 42}
assert template.fn(**test_input) == my_func(**test_input)
def test_template_matches(self):
"""Test matching URIs against a template."""
def my_func(key: str, value: int) -> dict:
return {"key": key, "value": value}
template = ResourceTemplate.from_function(
fn=my_func,
uri_template="test://{key}/{value}",
name="test",
)
# Valid match
params = template.matches("test://foo/123")
assert params == {"key": "foo", "value": "123"}
# No match
assert template.matches("test://foo") is None
assert template.matches("other://foo/123") is None
def test_template_matches_with_prefix(self):
"""Test matching URIs against a template with a prefix."""
def my_func(key: str, value: int) -> dict:
return {"key": key, "value": value}
template = ResourceTemplate.from_function(
fn=my_func,
uri_template="app+test://{key}/{value}",
name="test",
)
# Valid match
params = template.matches("app+test://foo/123")
assert params == {"key": "foo", "value": "123"}
# No match
assert template.matches("test://foo/123") is None
assert template.matches("test://foo") is None
assert template.matches("other://foo/123") is None
def test_template_uri_validation(self):
"""Test validation rule: URI template must have at least one parameter."""
def my_func() -> dict:
return {"data": "value"}
with pytest.raises(
ValueError, match="URI template must contain at least one parameter"
):
ResourceTemplate.from_function(
fn=my_func,
uri_template="test://no-params",
name="test",
)
def test_template_uri_params_subset_of_function_params(self):
"""Test validation rule: URI parameters must be a subset of function parameters."""
def my_func(key: str, value: int) -> dict:
return {"key": key, "value": value}
# This should work - URI params are a subset of function params
template = ResourceTemplate.from_function(
fn=my_func,
uri_template="test://{key}/{value}",
name="test",
)
assert template.uri_template == "test://{key}/{value}"
# This should fail - 'unknown' is not a function parameter
with pytest.raises(
ValueError,
match="Required function arguments .* must be a subset of the URI parameters",
):
ResourceTemplate.from_function(
fn=my_func,
uri_template="test://{key}/{unknown}",
name="test",
)
def test_required_params_subset_of_uri_params(self):
"""Test validation rule: Required function parameters must be in URI parameters."""
# Function with required parameters
def func_with_required(
required_param: str, optional_param: str = "default"
) -> dict:
return {"required": required_param, "optional": optional_param}
# This should work - required param is in URI
template = ResourceTemplate.from_function(
fn=func_with_required,
uri_template="test://{required_param}",
name="test",
)
assert template.uri_template == "test://{required_param}"
# This should fail - required param is not in URI
with pytest.raises(
ValueError,
match="Required function arguments .* must be a subset of the URI parameters",
):
ResourceTemplate.from_function(
fn=func_with_required,
uri_template="test://{optional_param}",
name="test",
)
def test_multiple_required_params(self):
"""Test validation with multiple required parameters."""
def multi_required(param1: str, param2: int, optional: str = "default") -> dict:
return {"p1": param1, "p2": param2, "opt": optional}
# This works - all required params in URI
template = ResourceTemplate.from_function(
fn=multi_required,
uri_template="test://{param1}/{param2}",
name="test",
)
assert template.uri_template == "test://{param1}/{param2}"
# This fails - missing one required param
with pytest.raises(
ValueError,
match="Required function arguments .* must be a subset of the URI parameters",
):
ResourceTemplate.from_function(
fn=multi_required,
uri_template="test://{param1}",
name="test",
)
async def test_create_resource(self):
"""Test creating a resource from a template."""
def my_func(key: str, value: int) -> dict:
return {"key": key, "value": value}
template = ResourceTemplate.from_function(
fn=my_func,
uri_template="test://{key}/{value}",
name="test",
)
resource = await template.create_resource(
"test://foo/123",
{"key": "foo", "value": 123},
)
assert isinstance(resource, FunctionResource)
content = await resource.read()
assert isinstance(content, str)
data = json.loads(content)
assert data == {"key": "foo", "value": 123}
async def test_async_text_resource(self):
"""Test creating a text resource from async function."""
async def greet(name: str) -> str:
return f"Hello, {name}!"
template = ResourceTemplate.from_function(
fn=greet,
uri_template="greet://{name}",
name="greeter",
)
resource = await template.create_resource(
"greet://world",
{"name": "world"},
)
assert isinstance(resource, FunctionResource)
content = await resource.read()
assert content == "Hello, world!"
async def test_async_binary_resource(self):
"""Test creating a binary resource from async function."""
async def get_bytes(value: str) -> bytes:
return value.encode()
template = ResourceTemplate.from_function(
fn=get_bytes,
uri_template="bytes://{value}",
name="bytes",
)
resource = await template.create_resource(
"bytes://test",
{"value": "test"},
)
assert isinstance(resource, FunctionResource)
content = await resource.read()
assert content == b"test"
async def test_basemodel_conversion(self):
"""Test handling of BaseModel types."""
class MyModel(BaseModel):
key: str
value: int
def get_data(key: str, value: int) -> MyModel:
return MyModel(key=key, value=value)
template = ResourceTemplate.from_function(
fn=get_data,
uri_template="test://{key}/{value}",
name="test",
)
resource = await template.create_resource(
"test://foo/123",
{"key": "foo", "value": 123},
)
assert isinstance(resource, FunctionResource)
content = await resource.read()
assert isinstance(content, str)
data = json.loads(content)
assert data == {"key": "foo", "value": 123}
async def test_custom_type_conversion(self):
"""Test handling of custom types."""
class CustomData:
def __init__(self, value: str):
self.value = value
def __str__(self) -> str:
return self.value
def get_data(value: str) -> CustomData:
return CustomData(value)
template = ResourceTemplate.from_function(
fn=get_data,
uri_template="test://{value}",
name="test",
)
resource = await template.create_resource(
"test://hello",
{"value": "hello"},
)
assert isinstance(resource, FunctionResource)
content = await resource.read()
assert content == '"hello"'
async def test_wildcard_param_can_create_resource(self):
"""Test that wildcard parameters are valid."""
def identity(path: str) -> str:
return path
template = ResourceTemplate.from_function(
fn=identity,
uri_template="test://{path*}.py",
name="test",
)
assert await template.create_resource(
"test://path/to/test.py",
{"path": "path/to/test.py"},
)
async def test_wildcard_param_matches(self):
def identify(path: str) -> str:
return path
template = ResourceTemplate.from_function(
fn=identify,
uri_template="test://src/{path*}.py",
name="test",
)
# Valid match
params = template.matches("test://src/path/to/test.py")
assert params == {"path": "path/to/test"}
async def test_multiple_wildcard_params(self):
"""Test that multiple wildcard parameters are valid."""
def identity(path: str, path2: str) -> str:
return f"{path}/{path2}"
template = ResourceTemplate.from_function(
fn=identity,
uri_template="test://{path*}/xyz/{path2*}",
name="test",
)
params = template.matches("test://path/to/xyz/abc")
assert params == {"path": "path/to", "path2": "abc"}
async def test_wildcard_param_with_regular_param(self):
"""Test that a wildcard parameter can be used with a regular parameter."""
def identity(prefix: str, path: str) -> str:
return f"{prefix}/{path}"
template = ResourceTemplate.from_function(
fn=identity,
uri_template="test://{prefix}/{path*}",
name="test",
)
params = template.matches("test://src/path/to/test.py")
assert params == {"prefix": "src", "path": "path/to/test.py"}
async def test_function_with_varargs_not_allowed(self):
def func(x: int, *args: int) -> int:
return x + sum(args)
with pytest.raises(
ValueError,
match=r"Functions with \*args are not supported as resource templates",
):
ResourceTemplate.from_function(
fn=func,
uri_template="test://{x}/{args*}",
name="test",
)
async def test_function_with_varkwargs_ok(self):
def func(x: int, **kwargs: int) -> int:
return x + sum(kwargs.values())
template = ResourceTemplate.from_function(
fn=func,
uri_template="test://{x}/{y}/{z}",
name="test",
)
assert template.uri_template == "test://{x}/{y}/{z}"
async def test_callable_object_as_template(self):
"""Test that a callable object can be used as a template."""
class MyTemplate:
"""This is my template"""
def __call__(self, x: str) -> str:
"""ignore this"""
return f"X was {x}"
template = ResourceTemplate.from_function(
fn=MyTemplate(),
uri_template="test://{x}",
name="test",
)
resource = await template.create_resource(
"test://foo",
{"x": "foo"},
)
assert isinstance(resource, FunctionResource)
content = await resource.read()
assert content == "X was foo"
class TestMatchUriTemplate:
"""Test match_uri_template function."""
@pytest.mark.parametrize(
"uri, expected_params",
[
("test://a/b", None),
("test://a/b/c", None),
("test://a/x/b", {"x": "x"}),
("test://a/x/y/b", None),
],
)
def test_match_uri_template_single_param(
self, uri: str, expected_params: dict[str, str]
):
"""Test that match_uri_template uses the slash delimiter."""
uri_template = "test://a/{x}/b"
result = match_uri_template(uri=uri, uri_template=uri_template)
assert result == expected_params
@pytest.mark.parametrize(
"uri, expected_params",
[
("test://foo/123", {"x": "foo", "y": "123"}),
("test://bar/456", {"x": "bar", "y": "456"}),
("test://foo/bar", {"x": "foo", "y": "bar"}),
("test://foo/bar/baz", None),
("test://foo/email@domain.com", {"x": "foo", "y": "email@domain.com"}),
("test://two words/foo", {"x": "two words", "y": "foo"}),
("test://two.words/foo+bar", {"x": "two.words", "y": "foo+bar"}),
(
f"test://escaped{quote('/', safe='')}word/bar",
{"x": "escaped/word", "y": "bar"},
),
(
f"test://escaped{quote('{', safe='')}x{quote('}', safe='')}word/bar",
{"x": "escaped{x}word", "y": "bar"},
),
("prefix+test://foo/123", None),
("test://foo", None),
("other://foo/123", None),
("t.est://foo/bar", None),
],
)
def test_match_uri_template_simple_params(
self, uri: str, expected_params: dict[str, str] | None
):
"""Test matching URIs against a template with simple parameters."""
uri_template = "test://{x}/{y}"
result = match_uri_template(uri=uri, uri_template=uri_template)
assert result == expected_params
@pytest.mark.parametrize(
"uri, expected_params",
[
("test://a/b/foo/c/d/123", {"x": "foo", "y": "123"}),
("test://a/b/bar/c/d/456", {"x": "bar", "y": "456"}),
("prefix+test://a/b/foo/c/d/123", None),
("test://a/b/foo", None),
("other://a/b/foo/c/d/123", None),
],
)
def test_match_uri_template_params_and_literal_segments(
self, uri: str, expected_params: dict[str, str] | None
):
"""Test matching URIs against a template with parameters and literal segments."""
uri_template = "test://a/b/{x}/c/d/{y}"
result = match_uri_template(uri=uri, uri_template=uri_template)
assert result == expected_params
@pytest.mark.parametrize(
"uri, expected_params",
[
("prefix+test://foo/test/123", {"x": "foo", "y": "123"}),
("prefix+test://bar/test/456", {"x": "bar", "y": "456"}),
("test://foo/test/123", None),
("other.prefix+test://foo/test/123", None),
("other+prefix+test://foo/test/123", None),
],
)
def test_match_uri_template_with_prefix(
self, uri: str, expected_params: dict[str, str] | None
):
"""Test matching URIs against a template with a prefix."""
uri_template = "prefix+test://{x}/test/{y}"
result = match_uri_template(uri=uri, uri_template=uri_template)
assert result == expected_params
def test_match_uri_template_quoted_params(self):
uri_template = "user://{name}/{email}"
quoted_name = quote("John Doe", safe="")
quoted_email = quote("john@example.com", safe="")
uri = f"user://{quoted_name}/{quoted_email}"
result = match_uri_template(uri=uri, uri_template=uri_template)
assert result == {"name": "John Doe", "email": "john@example.com"}
@pytest.mark.parametrize(
"uri, expected_params",
[
("test://a/b", None),
("test://a/b/c", None),
("test://a/x/b", {"x": "x"}),
("test://a/x/y/b", {"x": "x/y"}),
("bad-prefix://a/x/y/b", None),
("test://a/x/y/z", None),
],
)
def test_match_uri_template_wildcard_param(
self, uri: str, expected_params: dict[str, str]
):
"""Test that match_uri_template uses the slash delimiter."""
uri_template = "test://a/{x*}/b"
result = match_uri_template(uri=uri, uri_template=uri_template)
assert result == expected_params
@pytest.mark.parametrize(
"uri, expected_params",
[
("test://a/x/y/b/c/d", {"x": "x/y", "y": "c/d"}),
("bad-prefix://a/x/y/b/c/d", None),
("test://a/x/y/c/d", None),
("test://a/x/b/y", {"x": "x", "y": "y"}),
],
)
def test_match_uri_template_multiple_wildcard_params(
self, uri: str, expected_params: dict[str, str]
):
"""Test that match_uri_template uses the slash delimiter."""
uri_template = "test://a/{x*}/b/{y*}"
result = match_uri_template(uri=uri, uri_template=uri_template)
assert result == expected_params
def test_match_uri_template_wildcard_and_literal_param(self):
"""Test that match_uri_template uses the slash delimiter."""
uri = "test://a/x/y/b"
uri_template = "test://a/{x*}/{y}"
result = match_uri_template(uri=uri, uri_template=uri_template)
assert result == {"x": "x/y", "y": "b"}
def test_match_consecutive_params(self):
"""Test that consecutive parameters without a / are not matched."""
uri = "test://a/x/y"
uri_template = "test://a/{x}{y}"
result = match_uri_template(uri=uri, uri_template=uri_template)
assert result is None
@pytest.mark.parametrize(
"uri, expected_params",
[
("file://abc/xyz.py", {"path": "xyz"}),
("file://abc/x/y/z.py", {"path": "x/y/z"}),
("file://abc/x/y/z/.py", {"path": "x/y/z/"}),
("file://abc/x/y/z.md", None),
("file://x/y/z.txt", None),
],
)
def test_match_uri_template_with_non_slash_suffix(
self, uri: str, expected_params: dict[str, str]
):
uri_template = "file://abc/{path*}.py"
result = match_uri_template(uri=uri, uri_template=uri_template)
assert result == expected_params
class TestContextHandling:
"""Test context handling in resource templates."""
def test_context_parameter_detection(self):
"""Test that context parameters are properly detected in
ResourceTemplate.from_function()."""
def template_with_context(x: int, ctx: Context) -> str:
return str(x)
ResourceTemplate.from_function(
fn=template_with_context,
uri_template="test://{x}",
name="test",
)
def template_without_context(x: int) -> str:
return str(x)
ResourceTemplate.from_function(
fn=template_without_context,
uri_template="test://{x}",
name="test",
)
def test_parameterized_context_parameter_detection(self):
"""Test that parameterized context parameters are properly detected in
ResourceTemplate.from_function()."""
def template_with_context(x: int, ctx: Context) -> str:
return str(x)
ResourceTemplate.from_function(
fn=template_with_context,
uri_template="test://{x}",
name="test",
)
def test_parameterized_union_context_parameter_detection(self):
"""Test that context parameters in a union are properly detected in
ResourceTemplate.from_function()."""
def template_with_context(x: int, ctx: Context | None) -> str:
return str(x)
ResourceTemplate.from_function(
fn=template_with_context,
uri_template="test://{x}",
name="test",
)
async def test_context_injection(self):
"""Test that context is properly injected during resource creation."""
def resource_with_context(x: int, ctx: Context) -> str:
assert isinstance(ctx, Context)
return str(x)
template = ResourceTemplate.from_function(
fn=resource_with_context,
uri_template="test://{x}",
name="test",
)
from fastmcp import FastMCP
mcp = FastMCP()
context = Context(fastmcp=mcp)
with context:
resource = await template.create_resource(
"test://42",
{"x": 42},
)
assert isinstance(resource, FunctionResource)
content = await resource.read()
assert content == "42"
async def test_context_optional(self):
"""Test that context is optional when creating resources."""
def resource_with_context(x: int, ctx: Context | None = None) -> str:
return str(x)
template = ResourceTemplate.from_function(
fn=resource_with_context,
uri_template="test://{x}",
name="test",
)
# Even for optional context, we need to provide a context
from fastmcp import FastMCP
mcp = FastMCP()
context = Context(fastmcp=mcp)
with context:
resource = await template.create_resource(
"test://42",
{"x": 42},
)
assert isinstance(resource, FunctionResource)
content = await resource.read()
assert content == "42"