daphne/tests/test_websocket.py

# coding: utf8

import collections
from urllib import parse

from hypothesis import given, settings

import http_strategies
from http_base import DaphneTestCase, DaphneTestingInstance


class TestWebsocket(DaphneTestCase):
    """
    Tests WebSocket handshake, send and receive.
    """

    def assert_valid_websocket_scope(
        self,
        scope,
        path="/",
        params=None,
        headers=None,
        scheme=None,
        subprotocols=None,
    ):
        """
        Checks that the passed scope is a valid ASGI HTTP scope regarding types
        and some urlencoding things.
        """
        # Check overall keys
        self.assert_key_sets(
            required_keys={"type", "path", "query_string", "headers"},
            optional_keys={"scheme", "root_path", "client", "server", "subprotocols"},
            actual_keys=scope.keys(),
        )
        # Check that it is the right type
        self.assertEqual(scope["type"], "websocket")
        # Path
        self.assert_valid_path(scope["path"], path)
        # Scheme
        self.assertIn(scope.get("scheme", "ws"), ["ws", "wss"])
        if scheme:
            self.assertEqual(scheme, scope["scheme"])
        # Query string (byte string and still url encoded)
        query_string = scope["query_string"]
        self.assertIsInstance(query_string, bytes)
        if params:
            self.assertEqual(query_string, parse.urlencode(params or []).encode("ascii"))
        # Ordering of header names is not important, but the order of values for a header
        # name is. To assert whether that order is kept, we transform both the request
        # headers and the channel message headers into a dictionary
        # {name: [value1, value2, ...]} and check if they're equal.
        transformed_scope_headers = collections.defaultdict(list)
        for name, value in scope["headers"]:
            transformed_scope_headers.setdefault(name, [])
            # Make sure to split out any headers collapsed with commas
            for bit in value.split(b","):
                if bit.strip():
                    transformed_scope_headers[name].append(bit.strip())
        transformed_request_headers = collections.defaultdict(list)
        for name, value in (headers or []):
            expected_name = name.lower().strip().encode("ascii")
            expected_value = value.strip().encode("ascii")
            # Make sure to split out any headers collapsed with commas
            transformed_request_headers.setdefault(expected_name, [])
            for bit in expected_value.split(b","):
                if bit.strip():
                    transformed_request_headers[expected_name].append(bit.strip())
        for name, value in transformed_request_headers.items():
            self.assertIn(name, transformed_scope_headers)
            self.assertEqual(value, transformed_scope_headers[name])
        # Root path
        self.assertIsInstance(scope.get("root_path", ""), str)
        # Client and server addresses
        client = scope.get("client")
        if client is not None:
            self.assert_valid_address_and_port(client)
        server = scope.get("server")
        if server is not None:
            self.assert_valid_address_and_port(server)
        # Subprotocols
        scope_subprotocols = scope.get("subprotocols", [])
        if scope_subprotocols:
            assert all(isinstance(x, str) for x in scope_subprotocols)
        if subprotocols:
            assert sorted(scope_subprotocols) == sorted(subprotocols)

    def assert_valid_websocket_connect_message(self, message):
        """
        Asserts that a message is a valid http.request message
        """
        # Check overall keys
        self.assert_key_sets(
            required_keys={"type"},
            optional_keys=set(),
            actual_keys=message.keys(),
        )
        # Check that it is the right type
        self.assertEqual(message["type"], "websocket.connect")

    def test_accept(self):
        """
        Tests we can open and accept a socket.
        """
        with DaphneTestingInstance() as test_app:
            test_app.add_send_messages([
                {
                    "type": "websocket.accept",
                }
            ])
            self.websocket_handshake(test_app)
            # Validate the scope and messages we got
            scope, messages = test_app.get_received()
            self.assert_valid_websocket_scope(scope)
            self.assert_valid_websocket_connect_message(messages[0])

    def test_reject(self):
        """
        Tests we can reject a socket and it won't complete the handshake.
        """
        with DaphneTestingInstance() as test_app:
            test_app.add_send_messages([
                {
                    "type": "websocket.close",
                }
            ])
            with self.assertRaises(RuntimeError):
                self.websocket_handshake(test_app)

    def test_subprotocols(self):
        """
        Tests that we can ask for subprotocols and then select one.
        """
        subprotocols = ["proto1", "proto2"]
        with DaphneTestingInstance() as test_app:
            test_app.add_send_messages([
                {
                    "type": "websocket.accept",
                    "subprotocol": "proto2",
                }
            ])
            _, subprotocol = self.websocket_handshake(test_app, subprotocols=subprotocols)
            # Validate the scope and messages we got
            assert subprotocol == "proto2"
            scope, messages = test_app.get_received()
            self.assert_valid_websocket_scope(scope, subprotocols=subprotocols)
            self.assert_valid_websocket_connect_message(messages[0])

    @given(
        request_path=http_strategies.http_path(),
        request_params=http_strategies.query_params(),
        request_headers=http_strategies.headers(),
    )
    @settings(max_examples=5, deadline=2000)
    def test_http_bits(
        self,
        request_path,
        request_params,
        request_headers,
    ):
        """
        Tests that various HTTP-level bits (query string params, path, headers)
        carry over into the scope.
        """
        with DaphneTestingInstance() as test_app:
            test_app.add_send_messages([
                {
                    "type": "websocket.accept",
                }
            ])
            self.websocket_handshake(
                test_app,
                path=request_path,
                params=request_params,
                headers=request_headers,
            )
            # Validate the scope and messages we got
            scope, messages = test_app.get_received()
            self.assert_valid_websocket_scope(
                scope,
                path=request_path,
                params=request_params,
                headers=request_headers,
            )
            self.assert_valid_websocket_connect_message(messages[0])

    def test_text_frames(self):
        """
        Tests we can send and receive text frames.
        """
        with DaphneTestingInstance() as test_app:
            # Connect
            test_app.add_send_messages([
                {
                    "type": "websocket.accept",
                }
            ])
            sock, _ = self.websocket_handshake(test_app)
            _, messages = test_app.get_received()
            self.assert_valid_websocket_connect_message(messages[0])
            # Prep frame for it to send
            test_app.add_send_messages([
                {
                    "type": "websocket.send",
                    "text": "here be dragons 🐉",
                }
            ])
            # Send it a frame
            self.websocket_send_frame(sock, "what is here? 🌍")
            # Receive a frame and make sure it's correct
            assert self.websocket_receive_frame(sock) == "here be dragons 🐉"
            # Make sure it got our frame
            _, messages = test_app.get_received()
            assert messages[1] == {"type": "websocket.receive", "text": "what is here? 🌍"}

    def test_binary_frames(self):
        """
        Tests we can send and receive binary frames with things that are very
        much not valid UTF-8.
        """
        with DaphneTestingInstance() as test_app:
            # Connect
            test_app.add_send_messages([
                {
                    "type": "websocket.accept",
                }
            ])
            sock, _ = self.websocket_handshake(test_app)
            _, messages = test_app.get_received()
            self.assert_valid_websocket_connect_message(messages[0])
            # Prep frame for it to send
            test_app.add_send_messages([
                {
                    "type": "websocket.send",
                    "bytes": b"here be \xe2 bytes",
                }
            ])
            # Send it a frame
            self.websocket_send_frame(sock, b"what is here? \xe2")
            # Receive a frame and make sure it's correct
            assert self.websocket_receive_frame(sock) == b"here be \xe2 bytes"
            # Make sure it got our frame
            _, messages = test_app.get_received()
            assert messages[1] == {"type": "websocket.receive", "bytes": b"what is here? \xe2"}