Use uuid4 for request IDs

Fixes #7

jsonrpc_base/jsonrpc.py

@@ -1,8 +1,7 @@
 import inspect
 import json
 import logging
-import random
-import sys
+import uuid
 
 _LOGGER = logging.getLogger(__name__)
 
@@ -126,9 +125,7 @@ def __request(self, method_name, args=None, kwargs=None):
         if kwargs.pop('_notification', False):
             msg_id = None
         else:
-            # some JSON-RPC servers complain when receiving str(uuid.uuid4()).
-            # Let's pick something simpler.
-            msg_id = random.randint(1, sys.maxsize)
+            msg_id = str(uuid.uuid4())
 
         if args and kwargs:
             raise ProtocolError(

tests.py

@@ -1,29 +1,14 @@
-import contextlib
 import json
-import random
-import sys
 
 import pytest
-from unittest.mock import Mock
+from unittest import mock
 
 import jsonrpc_base
 from jsonrpc_base import Server, ProtocolError, TransportError
 
 pytestmark = pytest.mark.asyncio
 
 
-class DummyFile(object):
-    def write(self, x): pass
-
-
-@contextlib.contextmanager
-def block_stderr():
-    real_stderr = sys.stderr
-    sys.stderr = DummyFile()
-    yield
-    sys.stderr = real_stderr
-
-
 class MockTransportError(ValueError):
     """Test exception representing a transport library error."""
 
@@ -56,12 +41,6 @@ def assertSameJSON(json1, json2):
     assert json.loads(json1) == json.loads(json2)
 
 
-@pytest.fixture(autouse=True)
-def mock_rand():
-    """Mock the build in rand method for determinism in tests."""
-    random.randint = Mock(return_value=1)
-
-
 @pytest.fixture
 def server():
     """Get the mock server object"""
@@ -205,6 +184,7 @@ def handler(message):
 def test_calls(server):
     # rpc call with positional parameters:
     def handler1(message):
+        assert message.msg_id == "abcd-1234"
         assert message.params == [42, 23]
         return {
             "jsonrpc": "2.0",
@@ -213,7 +193,8 @@ def handler1(message):
         }
 
     server._handler = handler1
-    assert server.subtract(42, 23) == 19
+    with mock.patch("uuid.uuid4", return_value="abcd-1234"):
+        assert server.subtract(42, 23) == 19
 
     # rpc call with named parameters
     def handler2(message):
@@ -320,9 +301,8 @@ def bad_handler():
 
     # receive_request will normally print traceback when an exception is caught
     # This isn't necessary for the test
-    with block_stderr():
-        response = server.receive_request(jsonrpc_base.Request(
-            'on_bad_handler', msg_id=1))
+    response = server.receive_request(jsonrpc_base.Request(
+        'on_bad_handler', msg_id=1))
     assert response.error['code'] == -32000
     assert response.error['message'] == 'Server Error: Bad Server Handler'