L2SS-392: Add opcua client test that talks to a server instead of mocking one. Fix call_method.

tangostationcontrol/tangostationcontrol/clients/opcua_client.py

@@ -117,7 +117,7 @@ class OPCUAConnection(AsyncCommClient):
         return path
 
 
-    async def setup_attribute(self, annotation, attribute):
+    async def setup_protocol_attribute(self, annotation, attribute):
         # process the annotation
         path = self.get_node_path(annotation)
 
@@ -142,6 +142,11 @@ class OPCUAConnection(AsyncCommClient):
         except:
             pass
 
+        return prot_attr
+
+    async def setup_attribute(self, annotation, attribute):
+        prot_attr = await self.setup_protocol_attribute(annotation, attribute)
+
         # Tango will call these from a separate polling thread.
         def read_function():
             return asyncio.run_coroutine_threadsafe(prot_attr.read_function(), self.event_loop).result()
@@ -157,11 +162,13 @@ class OPCUAConnection(AsyncCommClient):
         method_path = self.get_node_path(method_path)
 
         try:
-            node = await self.obj.get_child(method_path[:-1])
+            node = await self.obj.get_child(method_path[:-1]) if len(method_path) > 1 else self.obj
             result = await node.call_method(method_path[-1], *args)
         except Exception as e:
             raise Exception(f"Calling method {method_path} failed") from e
 
+        return result
+
 
     def call_method(self, method_path, *args):
         return asyncio.run_coroutine_threadsafe(self._call_method(method_path, *args), self.event_loop).result()

tangostationcontrol/tangostationcontrol/test/clients/test_opcua_client_against_server.py

+import asyncua
+import numpy
+
+from clients.opcua_client import OPCUAConnection
+
+from test import base
+
+
+class TestClientServer(base.AsyncTestCase):
+    """ Test the OPCUAConnection against an OPCUA server we instantiate ourselves. """
+
+    async def setup_server(self, port):
+        """ Setup a server on a dedicated port for the test, to allow
+            the tests to be run in parallel. """
+
+        # where we will run the server
+        self.endpoint = f"opc.tcp://127.0.0.1:{port}"
+        self.namespace = "http://example.com"
+
+        # setup an OPC-UA server
+        self.server = asyncua.Server()
+        await self.server.init()
+        self.server.set_endpoint(self.endpoint)
+        self.server.set_server_name(f"Test server spawned by {__file__}")
+
+        # create an interface
+        idx = await self.server.register_namespace(self.namespace)
+        obj = self.server.get_objects_node()
+
+        # add double_R/double_RW
+        double_R = await obj.add_variable(idx, "double_R", 42.0)
+        double_RW = await obj.add_variable(idx, "double_RW", 42.0)
+        await double_RW.set_writable()
+
+        # add methods
+        @asyncua.uamethod
+        def multiply(parent, x, y):
+            return x * y
+
+        @asyncua.uamethod
+        def procedure(parent):
+            return
+
+        multiply_method = await obj.add_method(idx, "multiply", multiply, [asyncua.ua.VariantType.Double, asyncua.ua.VariantType.Int64], [asyncua.ua.VariantType.Double])
+        procedure_method = await obj.add_method(idx, "procedure", procedure, [], [])
+
+        # run the server
+        await self.server.start()
+
+    async def setUp(self):
+        self.server = None
+
+    async def tearDown(self):
+        if self.server:
+            await self.server.stop()
+
+    def fault_func(self):
+        raise Exception("FAULT")
+
+    async def test_opcua_connection(self):
+        await self.setup_server(14840)
+
+        test_client = OPCUAConnection(self.endpoint, self.namespace, 5, self.fault_func, self.loop)
+        try:
+            await test_client.start()
+        finally:
+            await test_client.stop()
+
+    async def test_read_attribute(self):
+        await self.setup_server(14841)
+
+        test_client = OPCUAConnection(self.endpoint, self.namespace, 5, self.fault_func, self.loop)
+        try:
+            await test_client.start()
+
+            # setup the attribute
+            class attribute(object):
+                dim_x = 1
+                dim_y = 0
+                numpy_type = numpy.double
+
+            prot_attr = await test_client.setup_protocol_attribute(["double_R"], attribute())
+
+            # read it from the server
+            self.assertEqual(42.0, await prot_attr.read_function())
+        finally:
+            await test_client.stop()
+
+    async def test_write_attribute(self):
+        await self.setup_server(14842)
+
+        test_client = OPCUAConnection(self.endpoint, self.namespace, 5, self.fault_func, self.loop)
+        try:
+            await test_client.start()
+
+            # setup the attribute
+            class attribute(object):
+                dim_x = 1
+                dim_y = 0
+                numpy_type = numpy.double
+
+            prot_attr = await test_client.setup_protocol_attribute(["double_RW"], attribute())
+
+            # write it to the server and read it back to verify
+            await prot_attr.write_function(123.0)
+
+            self.assertEqual(123.0, await prot_attr.read_function())
+        finally:
+            await test_client.stop()
+
+    async def test_method_without_args(self):
+        await self.setup_server(14843)
+
+        test_client = OPCUAConnection(self.endpoint, self.namespace, 5, self.fault_func, self.loop)
+        try:
+            await test_client.start()
+
+            self.assertEqual(None, await test_client._call_method(["procedure"]))
+        finally:
+            await test_client.stop()
+
+    async def test_method_with_args(self):
+        await self.setup_server(14843)
+
+        test_client = OPCUAConnection(self.endpoint, self.namespace, 5, self.fault_func, self.loop)
+        try:
+            await test_client.start()
+
+            self.assertEqual(21.0, await test_client._call_method(
+                ["multiply"],
+                asyncua.ua.Variant(3.0, asyncua.ua.VariantType.Double), 
+                asyncua.ua.Variant(7, asyncua.ua.VariantType.Int64)))
+        finally:
+            await test_client.stop()