Merge pull request #12 from QualiSystems/feature/borismod_context2

add ErrorHandlingContext class

cloudshell/core/context/error_handling_context.py

@@ -0,0 +1,44 @@
+import traceback
+
+from cloudshell.core.context.context_service import ContextBasedService
+
+
+class ErrorHandlingContext(ContextBasedService):
+    def __init__(self, context, logger):
+        """
+        Initializes an instance of ErrorHandlingContext
+        Allows proper logging on exception
+        :param context: ResourceCommandContext
+        :param logger: Logger
+        :type logger: Logger
+        """
+        self.context = context
+        self.logger = logger
+
+    def get_objects(self):
+        """
+        Returns context instance. Should not be called explicitly
+        :return:  ErrorHandlingContext
+        :rtype ErrorHandlingContext
+        """
+        return self
+
+    def context_started(self):
+        """
+        Called upon block start. Should not be called explicitly
+        :return:  ErrorHandlingContext
+        :rtype ErrorHandlingContext
+        """
+        return self
+
+    def context_ended(self, exc_type, exc_value, exc_traceback):
+        """
+        Called upon block end. Should not be called explicitly
+        In case of exception during the block execution logs the error with debug severity
+        and allows the same exception to be thrown
+        :return:  ErrorHandlingContext
+        :rtype ErrorHandlingContext
+        """
+        lines = traceback.format_exception(exc_type, exc_value, exc_traceback)
+        self.logger.error('Error occurred: ' + ''.join(lines))
+        return False

tests/core/context/test_error_handling_context.py

@@ -0,0 +1,19 @@
+from unittest import TestCase
+
+from mock import Mock, MagicMock
+
+from cloudshell.core.context.error_handling_context import ErrorHandlingContext
+
+
+class TestLoggingSession(TestCase):
+
+    def test_log_written_when_exception_occurs(self):
+        context = Mock()
+        logger = Mock()
+        logger.error = MagicMock()
+        try:
+            with ErrorHandlingContext(context=context, logger=logger):
+                raise ValueError('some value error occurred')
+        except ValueError:
+            self.assertTrue(logger.error.called)
+