Various Error path handling tests and fixes.

varlink/error.py

@@ -32,6 +32,9 @@ def new(cls, message, namespaced=False):
         elif message["error"] == "org.varlink.service.MethodNotImplemented":
             return MethodNotImplemented.new(message, namespaced)
 
+        elif message["error"] == "org.varlink.service.MethodNotFound":
+            return MethodNotFound.new(message, namespaced)
+
         else:
             return cls(message, namespaced)
 
@@ -45,15 +48,19 @@ def error(self):
         """returns the exception varlink error name"""
         return self.args[0].get("error")
 
-    def parameters(self, namespaced=False):
-        """returns the exception varlink error parameters"""
+    @staticmethod
+    def message_parameters(message, namespaced=False):
         if namespaced:
             return json.loads(
-                json.dumps(self.args[0]["parameters"]),
+                json.dumps(message["parameters"]),
                 object_hook=lambda d: SimpleNamespace(**d),
             )
         else:
-            return self.args[0].get("parameters")
+            return message.get("parameters")
+
+    def parameters(self, namespaced=False):
+        """returns the exception varlink error parameters"""
+        return self.message_parameters(self.args[0], namespaced)
 
     def as_dict(self):
         return self.args[0]
@@ -64,9 +71,11 @@ class InterfaceNotFound(VarlinkError):
 
     @classmethod
     def new(cls, message, namespaced=False):
-        return cls(
-            namespaced and message["parameters"].interface or message["parameters"].get("interface", None)
-        )
+        parameters = cls.message_parameters(message, namespaced)
+        if parameters is None:
+            # Back-compatibility error
+            raise KeyError("parameters")
+        return cls(parameters.interface if namespaced else parameters.get("interface", None))
 
     def __init__(self, interface):
         VarlinkError.__init__(
@@ -83,7 +92,8 @@ class MethodNotFound(VarlinkError):
 
     @classmethod
     def new(cls, message, namespaced=False):
-        return cls(namespaced and message["parameters"].method or message["parameters"].get("method", None))
+        parameters = cls.message_parameters(message, namespaced)
+        return cls(namespaced and parameters.method or parameters.get("method", None))
 
     def __init__(self, method):
         VarlinkError.__init__(
@@ -100,7 +110,8 @@ class MethodNotImplemented(VarlinkError):
 
     @classmethod
     def new(cls, message, namespaced=False):
-        return cls(namespaced and message["parameters"].method or message["parameters"].get("method", None))
+        parameters = cls.message_parameters(message, namespaced)
+        return cls(namespaced and parameters.method or parameters.get("method", None))
 
     def __init__(self, method):
         VarlinkError.__init__(
@@ -117,9 +128,8 @@ class InvalidParameter(VarlinkError):
 
     @classmethod
     def new(cls, message, namespaced=False):
-        return cls(
-            namespaced and message["parameters"].parameter or message["parameters"].get("parameter", None)
-        )
+        parameters = cls.message_parameters(message, namespaced)
+        return cls(namespaced and parameters.parameter or parameters.get("parameter", None))
 
     def __init__(self, name):
         VarlinkError.__init__(

varlink/tests/test_error.py

@@ -0,0 +1,34 @@
+import json
+import unittest
+
+import varlink
+
+
+class OneMessageClientHandler(varlink.ClientInterfaceHandler):
+    def __init__(self, interface, namespaced, next_message):
+        # No interface but we do not use them
+        super().__init__(interface, namespaced)
+        self.next_message = next_message
+
+    def _next_message(self):
+        yield self.next_message
+
+
+class TestError(unittest.TestCase):
+    def test_pack_unpack(self):
+        dummy_if = varlink.Interface("interface org.example.dummy")
+        for error in [
+            varlink.InterfaceNotFound("org.varlink.notfound"),
+            varlink.MethodNotFound("Method"),
+            varlink.MethodNotImplemented("Abstract"),
+            varlink.InvalidParameter("Struct.param"),
+        ]:
+            for namespaced in (True, False):
+                with self.subTest(error=error, namespaced=namespaced):
+                    # encode error
+                    encoded = json.dumps(error, cls=varlink.VarlinkEncoder)
+
+                    # Emulates the client receiving an error
+                    handler = OneMessageClientHandler(dummy_if, namespaced, encoded)
+                    with self.assertRaises(error.__class__):
+                        handler._next_varlink_message()