avocado.result: Introduce TestResultProxy

Create a class that has the same interface as a
test result, but in fact has a list of test result
objects and can write to each of them any time
a test result operation is called. This is the
first step to make multiple output plugins to
work.
Signed-off-by: NLucas Meneghel Rodrigues <lmr@redhat.com>

avocado/result.py

@@ -21,6 +21,70 @@ used by the test runner.
 """
 
 
+class InvalidOutputPlugin(Exception):
+    pass
+
+
+class TestResultProxy(object):
+
+    def __init__(self):
+        self.output_plugins = []
+        self.console_plugin = None
+
+    def __getattr__(self, attr):
+        for output_plugin in self.output_plugins:
+            if hasattr(output_plugin, attr):
+                return getattr(output_plugin, attr)
+            else:
+                return None
+
+    def add_output_plugin(self, plugin):
+        if not isinstance(plugin, TestResult):
+            raise InvalidOutputPlugin("Object %s is not an instance of "
+                                      "TestResult" % plugin)
+        self.output_plugins.append(plugin)
+
+    def start_tests(self):
+        for output_plugin in self.output_plugins:
+            output_plugin.start_tests()
+
+    def end_tests(self):
+        for output_plugin in self.output_plugins:
+            output_plugin.end_tests()
+
+    def start_test(self, test):
+        for output_plugin in self.output_plugins:
+            output_plugin.start_test(test)
+
+    def end_test(self, test):
+        for output_plugin in self.output_plugins:
+            output_plugin.end_test(test)
+
+    def add_pass(self, test):
+        for output_plugin in self.output_plugins:
+            output_plugin.add_pass(test)
+
+    def add_error(self, test):
+        for output_plugin in self.output_plugins:
+            output_plugin.add_error(test)
+
+    def add_fail(self, test):
+        for output_plugin in self.output_plugins:
+            output_plugin.add_fail(test)
+
+    def add_skip(self, test):
+        for output_plugin in self.output_plugins:
+            output_plugin.add_skip(test)
+
+    def add_warn(self, test):
+        for output_plugin in self.output_plugins:
+            output_plugin.add_warn(test)
+
+    def check_test(self, test):
+        for output_plugin in self.output_plugins:
+            output_plugin.check_test(test)
+
+
 class TestResult(object):
 
     """