Client proxy handle RPC with no arguments

src/p4p/rpc.py

@@ -252,27 +252,28 @@ class RPCProxyBase(object):
     scheme = None  # set to override automatic
 
 
-def _wrapMethod(K, V):
-    pv, req = V._call_PV, V._call_Request
+def _wrapMethod(name, meth):
+    pv, req = meth._call_PV, meth._call_Request
     if sys.version_info >= (3, 0):
-        S = inspect.getfullargspec(V)
+        S = inspect.getfullargspec(meth)
         keywords = S.varkw
     else:
-        S = inspect.getargspec(V)
+        S = inspect.getargspec(meth)
         keywords = S.keywords
+    defaults = S.defaults or [] # for getfullargspec().defaults can be None
 
     if S.varargs is not None or keywords is not None:
-        raise TypeError("vararg not supported for proxy method %s" % K)
+        raise TypeError("vararg not supported for proxy method %s" % name)
 
-    if len(S.args) != len(S.defaults):
-        raise TypeError("proxy method %s must specify types for all arguments" % K)
+    if len(S.args) != len(defaults):
+        raise TypeError("proxy method %s must specify types for all arguments" % name)
 
     try:
-        NT = NTURI(zip(S.args, S.defaults))
+        NT = NTURI(zip(S.args, defaults))
     except Exception as e:
-        raise TypeError("%s : failed to build method from %s, %s" % (e, S.args, S.defaults))
+        raise TypeError("%s : failed to build method from %s, %s" % (e, S.args, defaults))
 
-    @wraps(V)
+    @wraps(meth)
     def mcall(self, *args, **kws):
         pvname = pv % self.format
         try:

src/p4p/test/test_rpc.py

@@ -22,6 +22,9 @@ class TestService(object):
     def add(self, lhs, rhs):
         return float(lhs) + float(rhs)
 
+    @rpc(NTScalar('d'))
+    def magicnum(self):
+        return 42
 
 class TestRPCFull(RefTestCase):
 
@@ -110,6 +113,13 @@ def testAdd3(self):
             sum = ctxt.rpc(self.prefix + 'add', args)
             self.assertEqual(sum.value, 3.0)
 
+    def testMagic(self):
+        args = NTURI([
+        ]).wrap(self.prefix + 'magicnum', kws={
+        }, scheme='pva')
+        with Context(self.provider, useenv=False, conf=self.getconfig(), unwrap=False) as ctxt:
+            num = ctxt.rpc(self.prefix + 'magicnum', args)
+            self.assertEqual(num.value, 42)
 
 #class TestRPCProvider(TestRPCFull):
 #
@@ -142,13 +152,30 @@ def bar(A='i', B='s'):
         def another(X='s', Y='i'):
             pass
 
+        @rpccall('%smagicnum')
+        def magicnum():
+            pass
+
     def setUp(self):
         super(TestProxy, self).setUp()
         ctxt = self.MockContext()
         self.proxy = self.MyProxy(myarg=3, context=ctxt, format='pv:')
         self.assertEqual(self.proxy.myarg, 3)
         self.assertIs(self.proxy.context, ctxt)
 
+    def test_call0(self):
+        args, kws = self.proxy.magicnum()
+
+        self.assertEqual(args[0], 'pv:magicnum')
+        self.assertListEqual(args[1].tolist(), [
+            ('scheme', u'fake'),
+            ('authority', u''),
+            ('path', u'pv:magicnum'),
+            ('query', [])
+        ])
+        self.assertEqual(len(args), 2)
+        self.assertDictEqual(kws, {'request': None, 'throw': True, 'timeout': 3.0})
+
     def test_call1(self):
         args, kws = self.proxy.bar(4, 'one')