Fix parameters

Author: bcb

.pre-commit-config.yaml

@@ -9,26 +9,14 @@ repos:
       - id: black
         args: [--diff, --check]
 
-  - repo: https://github.com/PyCQA/pylint
-    rev: v2.15.5
+  - repo: local
     hooks:
-      - id: pylint
-        stages: [manual]
-        additional_dependencies:
-          - returns<1
-          - aiohttp<4
-          - aiozmq<1
-          - django<5
-          - fastapi<1
-          - flask<3
-          - flask-socketio<5.3.1
-          - jsonschema<5
-          - pytest
-          - pyzmq
-          - sanic
-          - tornado<7
-          - uvicorn<1
-          - websockets<11
+    -   id: pylint
+        name: pylint
+        entry: pylint
+        language: system
+        types: [python]
+        require_serial: true
 
   - repo: https://github.com/pre-commit/mirrors-mypy
     rev: v0.971

docs/dispatch.md

@@ -12,6 +12,9 @@ and gives a JSON-RPC response.
 
 ## Optional parameters
 
+The `dispatch` function has some optional parameters that allow you to
+customise how it works.
+
 ### methods
 
 This lets you specify the methods to dispatch to. It's an alternative to using
@@ -43,23 +46,36 @@ def greet(context, name):
 
 ### deserializer
 
-A function that parses the request string. Default is `json.loads`.
+A function that parses the JSON request string. Default is `json.loads`.
 
 ```python
 dispatch(request, deserializer=ujson.loads)
 ```
 
+### jsonrpc_validator
+
+A function that validates the request once the JSON string has been parsed. The
+function should raise an exception (any exception) if the request doesn't match
+the JSON-RPC spec (https://www.jsonrpc.org/specification). Default is
+`default_jsonrpc_validator` which uses Jsonschema to validate requests against
+a schema.
+
+To disable JSON-RPC validation, pass `jsonrpc_validator=lambda _: None`, which
+will improve performance because this validation takes around half the dispatch
+time.
+
+### args_validator
+
+A function that validates a request's parameters against the signature of the
+Python function that will be called for it. Note this should not validate the
+_values_ of the parameters, it should simply ensure the parameters match the
+Python function's signature. For reference, see the `validate_args` function in
+`dispatcher.py`, which is the default `args_validator`.
+
 ### serializer
 
 A function that serializes the response string. Default is `json.dumps`.
 
 ```python
 dispatch(request, serializer=ujson.dumps)
 ```
-
-### validator
-
-A function that validates the request once the json has been parsed. The
-function should raise an exception (any exception) if the request doesn't match
-the JSON-RPC spec. Default is `default_validator` which validates the request
-against a schema.

examples/fastapi_server.py

@@ -1,6 +1,6 @@
 """FastAPI server"""
 from fastapi import FastAPI, Request, Response
-import uvicorn  # type: ignore
+import uvicorn
 from jsonrpcserver import dispatch, method, Ok, Result
 
 app = FastAPI()

jsonrpcserver/async_main.py

@@ -5,7 +5,7 @@
 from .async_dispatcher import dispatch_to_response_pure
 from .async_methods import Methods, global_methods
 from .dispatcher import Deserialized
-from .main import default_validator, default_deserializer
+from .main import default_jsonrpc_validator, default_deserializer
 from .response import Response, to_serializable
 from .sentinels import NOCONTEXT
 from .utils import identity
@@ -20,7 +20,7 @@ async def dispatch_to_response(
     *,
     context: Any = NOCONTEXT,
     deserializer: Callable[[str], Deserialized] = default_deserializer,
-    validator: Callable[[Deserialized], Deserialized] = default_validator,
+    validator: Callable[[Deserialized], Deserialized] = default_jsonrpc_validator,
     post_process: Callable[[Response], Any] = identity,
 ) -> Union[Response, Iterable[Response], None]:
     return await dispatch_to_response_pure(

jsonrpcserver/dispatcher.py

@@ -31,6 +31,7 @@
 from .sentinels import NOCONTEXT, NOID
 from .utils import compose, make_list
 
+ArgsValidator = Callable[[Any, Request, Method], Result[Method, ErrorResult]]
 Deserialized = Union[Dict[str, Any], List[Dict[str, Any]]]
 
 logger = logging.getLogger(__name__)
@@ -120,7 +121,9 @@ def validate_result(result: Result[SuccessResult, ErrorResult]) -> None:
 
 
 def call(
-    request: Request, context: Any, method: Method
+    request: Request,
+    context: Any,
+    method: Method,
 ) -> Result[SuccessResult, ErrorResult]:
     """Call the method.
 
@@ -146,7 +149,9 @@ def call(
 
 
 def validate_args(
-    request: Request, context: Any, func: Method
+    request: Request,
+    context: Any,
+    func: Method,
 ) -> Result[Method, ErrorResult]:
     """Ensure the method can be called with the arguments given.
 
@@ -171,7 +176,10 @@ def get_method(methods: Methods, method_name: str) -> Result[Method, ErrorResult
 
 
 def dispatch_request(
-    methods: Methods, context: Any, request: Request
+    args_validator: ArgsValidator,
+    methods: Methods,
+    context: Any,
+    request: Request,
 ) -> Tuple[Request, Result[SuccessResult, ErrorResult]]:
     """Get the method, validates the arguments and calls the method.
 
@@ -182,7 +190,7 @@ def dispatch_request(
     return (
         request,
         get_method(methods, request.method)
-        .bind(partial(validate_args, request, context))
+        .bind(partial(args_validator, request, context))
         .bind(partial(call, request, context)),
     )
 
@@ -203,9 +211,10 @@ def not_notification(request_result: Any) -> bool:
 
 
 def dispatch_deserialized(
+    args_validator: ArgsValidator,
+    post_process: Callable[[Response], Response],
     methods: Methods,
     context: Any,
-    post_process: Callable[[Response], Response],
     deserialized: Deserialized,
 ) -> Union[Response, List[Response], None]:
     """This is simply continuing the pipeline from dispatch_to_response_pure. It exists
@@ -216,15 +225,17 @@ def dispatch_deserialized(
         applied to the Response(s).
     """
     results = map(
-        compose(partial(dispatch_request, methods, context), create_request),
+        compose(
+            partial(dispatch_request, args_validator, methods, context), create_request
+        ),
         make_list(deserialized),
     )
     responses = starmap(to_response, filter(not_notification, results))
     return extract_list(isinstance(deserialized, list), map(post_process, responses))
 
 
 def validate_request(
-    validator: Callable[[Deserialized], Deserialized], request: Deserialized
+    jsonrpc_validator: Callable[[Deserialized], Deserialized], request: Deserialized
 ) -> Result[Deserialized, ErrorResponse]:
     """Validate the request against a JSON-RPC schema.
 
@@ -233,9 +244,9 @@ def validate_request(
     Returns: Either the same request passed in or an Invalid request response.
     """
     try:
-        validator(request)
+        jsonrpc_validator(request)
     # Since the validator is unknown, the specific exception that will be raised is also
-    # unknown. Any exception raised we assume the request is invalid and  return an
+    # unknown. Any exception raised we assume the request is invalid and return an
     # "invalid request" response.
     except Exception:  # pylint: disable=broad-except
         return Failure(InvalidRequestResponse("The request failed schema validation"))
@@ -259,29 +270,31 @@ def deserialize_request(
 
 
 def dispatch_to_response_pure(
-    *,
+    args_validator: ArgsValidator,
     deserializer: Callable[[str], Deserialized],
-    validator: Callable[[Deserialized], Deserialized],
+    jsonrpc_validator: Callable[[Deserialized], Deserialized],
+    post_process: Callable[[Response], Response],
     methods: Methods,
     context: Any,
-    post_process: Callable[[Response], Response],
     request: str,
 ) -> Union[Response, List[Response], None]:
     """A function from JSON-RPC request string to Response namedtuple(s), (yet to be
     serialized to json).
 
     Returns: A single Response, a list of Responses, or None. None is given for
-        notifications or batches of notifications, to indicate that we should not
-        respond.
+        notifications or batches of notifications, to indicate that we should
+        not respond.
     """
     try:
         result = deserialize_request(deserializer, request).bind(
-            partial(validate_request, validator)
+            partial(validate_request, jsonrpc_validator)
         )
         return (
             post_process(result)
             if isinstance(result, Failure)
-            else dispatch_deserialized(methods, context, post_process, result.unwrap())
+            else dispatch_deserialized(
+                args_validator, post_process, methods, context, result.unwrap()
+            )
         )
     except Exception as exc:  # pylint: disable=broad-except
         # There was an error with the jsonrpcserver library.

jsonrpcserver/main.py

@@ -15,30 +15,38 @@
 
 from jsonschema.validators import validator_for  # type: ignore
 
-from .dispatcher import dispatch_to_response_pure, Deserialized
+from .dispatcher import (
+    ArgsValidator,
+    Deserialized,
+    dispatch_to_response_pure,
+    validate_args,
+)
 from .methods import Methods, global_methods
 from .response import Response, to_dict
 from .sentinels import NOCONTEXT
 from .utils import identity
 
 
+default_args_validator = validate_args
 default_deserializer = json.loads
 
-# Prepare the jsonschema validator. This is global so it loads only once, not every
-# time dispatch is called.
+# Prepare the jsonschema validator. This is global so it loads only once, not every time
+# dispatch is called.
 schema = json.loads(read_text(__package__, "request-schema.json"))
 klass = validator_for(schema)
 klass.check_schema(schema)
-default_validator = klass(schema).validate
+default_jsonrpc_validator = klass(schema).validate
 
 
 def dispatch_to_response(
     request: str,
-    methods: Optional[Methods] = None,
-    *,
+    methods: Methods = global_methods,
     context: Any = NOCONTEXT,
+    args_validator: ArgsValidator = default_args_validator,
     deserializer: Callable[[str], Deserialized] = json.loads,
-    validator: Callable[[Deserialized], Deserialized] = default_validator,
+    jsonrpc_validator: Callable[
+        [Deserialized], Deserialized
+    ] = default_jsonrpc_validator,
     post_process: Callable[[Response], Any] = identity,
 ) -> Union[Response, List[Response], None]:
     """Takes a JSON-RPC request string and dispatches it to method(s), giving Response
@@ -54,9 +62,11 @@ def dispatch_to_response(
             populated with the @method decorator.
         context: If given, will be passed as the first argument to methods.
         deserializer: Function that deserializes the request string.
-        validator: Function that validates the JSON-RPC request. The function should
-            raise an exception if the request is invalid. To disable validation, pass
-            lambda _: None.
+        args_validator: Function that validates that the parameters in the request match
+            the Python function being called.
+        jsonrpc_validator: Function that validates the JSON-RPC request. The function
+            should raise an exception if the request is invalid. To disable validation,
+            pass lambda _: None.
         post_process: Function that will be applied to Responses.
 
     Returns:
@@ -67,12 +77,13 @@ def dispatch_to_response(
        '{"jsonrpc": "2.0", "result": "pong", "id": 1}'
     """
     return dispatch_to_response_pure(
-        deserializer=deserializer,
-        validator=validator,
-        post_process=post_process,
-        context=context,
-        methods=global_methods if methods is None else methods,
-        request=request,
+        args_validator,
+        deserializer,
+        jsonrpc_validator,
+        post_process,
+        methods,
+        context,
+        request,
     )
 
 

tests/test_async_dispatcher.py

@@ -10,7 +10,7 @@
     dispatch_request,
     dispatch_to_response_pure,
 )
-from jsonrpcserver.main import default_deserializer, default_validator
+from jsonrpcserver.main import default_deserializer, default_jsonrpc_validator
 from jsonrpcserver.codes import ERROR_INTERNAL_ERROR, ERROR_SERVER_ERROR
 from jsonrpcserver.exceptions import JsonRpcError
 from jsonrpcserver.request import Request
@@ -76,7 +76,7 @@ async def test_dispatch_deserialized() -> None:
 async def test_dispatch_to_response_pure_success() -> None:
     assert await dispatch_to_response_pure(
         deserializer=default_deserializer,
-        validator=default_validator,
+        validator=default_jsonrpc_validator,
         post_process=identity,
         context=NOCONTEXT,
         methods={"ping": ping},
@@ -92,7 +92,7 @@ async def ping() -> Result:
 
     assert await dispatch_to_response_pure(
         deserializer=default_deserializer,
-        validator=default_validator,
+        validator=default_jsonrpc_validator,
         post_process=identity,
         context=NOCONTEXT,
         methods={"ping": ping},