Fix handling of MultipleException

Change-Id: I187c364db9e41c437e9d6dbcbc6df7bfadba43bb

tobiko/__init__.py

@@ -33,6 +33,8 @@ fail = _asserts.fail
 TobikoException = _exception.TobikoException
 check_valid_type = _exception.check_valid_type
 exc_info = _exception.exc_info
+handle_multiple_exceptions = _exception.handle_multiple_exceptions
+list_exc_infos = _exception.list_exc_infos
 
 is_fixture = _fixture.is_fixture
 get_fixture = _fixture.get_fixture

tobiko/common/_exception.py

@@ -13,11 +13,13 @@
 #    under the License.
 from __future__ import absolute_import
 
+import contextlib
 import collections
 import sys
 
 from oslo_log import log
 import six
+import testtools
 
 
 LOG = log.getLogger(__name__)
@@ -107,3 +109,36 @@ def exc_info(reraise=True):
     info = ExceptionInfo(*sys.exc_info())
     info.reraise_on_exit = reraise
     return info
+
+
+@contextlib.contextmanager
+def handle_multiple_exceptions():
+    try:
+        yield
+    except testtools.MultipleExceptions as exc:
+        exc_infos = list_exc_infos()
+        if exc_infos:
+            for info in exc_infos[1:]:
+                LOG.exception("Unhandled exception:", exc_info=info)
+            six.reraise(*exc_infos[0])
+        else:
+            LOG.debug('empty MultipleExceptions: %s', str(exc))
+
+
+def list_exc_infos(exc_info=None):
+    # pylint: disable=redefined-outer-name
+    exc_info = exc_info or sys.exc_info()
+    result = []
+    if exc_info[0]:
+        visited = set()
+        visiting = [exc_info]
+        while visiting:
+            exc_info = visiting.pop()
+            _, exc, _ = exc_info
+            if exc not in visited:
+                visited.add(exc)
+                if isinstance(exc, testtools.MultipleExceptions):
+                    visiting.extend(reversed(exc.args))
+                else:
+                    result.append(exc_info)
+    return result

tobiko/common/_fixture.py

@@ -23,6 +23,7 @@ import testtools
 
 import tobiko
 from tobiko.common import _detail
+from tobiko.common import _exception
 
 
 LOG = log.getLogger(__name__)
@@ -98,33 +99,24 @@ def remove_fixture(obj, manager=None):
 def setup_fixture(obj, manager=None):
     '''Get registered fixture and setup it up'''
     fixture = get_fixture(obj, manager=manager)
-    try:
+    with _exception.handle_multiple_exceptions():
         fixture.setUp()
-    except testtools.MultipleExceptions as ex:
-        for exc_info in ex.args[1:]:
-            LOG.exception("Error setting up fixture %r",
-                          fixture.fixture_name, exc_info=exc_info)
-        six.reraise(*ex.args[0])
     return fixture
 
 
 def reset_fixture(obj, manager=None):
-    '''Get registered fixture and setup it up'''
+    '''Get registered fixture and reset it'''
     fixture = get_fixture(obj, manager=manager)
-    try:
+    with _exception.handle_multiple_exceptions():
         fixture.reset()
-    except testtools.MultipleExceptions as ex:
-        for exc_info in ex.args[1:]:
-            LOG.exception("Error reseting fixture %r",
-                          fixture.fixture_name, exc_info=exc_info)
-        six.reraise(*ex.args[0])
     return fixture
 
 
 def cleanup_fixture(obj, manager=None):
     '''Get registered fixture and clean it up'''
     fixture = get_fixture(obj, manager=manager)
-    fixture.cleanUp()
+    with _exception.handle_multiple_exceptions():
+        fixture.cleanUp()
     return fixture
 
 

tobiko/tests/unit/test_exception.py

@@ -17,6 +17,7 @@ import sys
 
 import tobiko
 from tobiko.tests import unit
+import testtools
 
 
 class SomeException(tobiko.TobikoException):
@@ -122,3 +123,95 @@ class TestExcInfo(unit.TobikoUnitTest):
 
         reraised = self.assertRaises(RuntimeError, exc_info.reraise)
         self.assertIs(exc_value, reraised)
+
+
+class TestListExcInfo(unit.TobikoUnitTest):
+
+    def test_list_exc_info(self):
+        result = tobiko.list_exc_infos()
+        self.assertEqual([], result)
+
+    def test_list_exc_info_with_info(self):
+        error = make_exception(RuntimeError, 'error')
+        result = tobiko.list_exc_infos(exc_info=error)
+        self.assertEqual([error], result)
+
+    def test_list_exc_info_handling_exception(self):
+        try:
+            raise RuntimeError('error')
+        except RuntimeError:
+            result = tobiko.list_exc_infos()
+            self.assertEqual([sys.exc_info()], result)
+
+    def test_list_exc_info_handling_empty_multiple_exceptions(self):
+        error = make_exception(testtools.MultipleExceptions)
+        result = tobiko.list_exc_infos(exc_info=error)
+        self.assertEqual([], result)
+
+    def test_list_exc_info_handling_multiple_exceptions(self):
+        a = make_exception(RuntimeError, 'a')
+        b = make_exception(ValueError, 'b')
+        c = make_exception(TypeError, 'c')
+        multi = make_exception(testtools.MultipleExceptions, a, b, c)
+        result = tobiko.list_exc_infos(exc_info=multi)
+        self.assertEqual([a, b, c], result)
+
+    def test_list_exc_info_handling_nested_multiple_exceptions(self):
+        a = make_exception(RuntimeError, 'a')
+        b = make_exception(ValueError, 'b')
+        c = make_exception(TypeError, 'c')
+        d = make_exception(IndexError, 'd')
+        inner = make_exception(testtools.MultipleExceptions, b, c)
+        multi = make_exception(testtools.MultipleExceptions, a, inner, d)
+        result = tobiko.list_exc_infos(exc_info=multi)
+        self.assertEqual([a, b, c, d], result)
+
+
+class TestHandleMultipleExceptions(unit.TobikoUnitTest):
+
+    def test_handle_multiple_exceptions(self):
+        with tobiko.handle_multiple_exceptions():
+            pass
+
+    def test_handle_multiple_exceptions_with_exception(self):
+        def run():
+            with tobiko.handle_multiple_exceptions():
+                raise RuntimeError('error')
+        self.assertRaises(RuntimeError, run)
+
+    def test_handle_multiple_exceptions_with_empty_multiple_exception(self):
+        with tobiko.handle_multiple_exceptions():
+            raise testtools.MultipleExceptions()
+
+    def test_handle_multiple_exceptions_with_multiple_exceptions(self):
+        a = make_exception(TypeError, 'a')
+        b = make_exception(ValueError, 'b')
+        c = make_exception(RuntimeError, 'c')
+
+        def run():
+            with tobiko.handle_multiple_exceptions():
+                raise testtools.MultipleExceptions(a, b, c)
+
+        ex = self.assertRaises(TypeError, run)
+        self.assertEqual(a[1], ex)
+
+    def test_handle_multiple_exceptions_with_nested_multiple_exceptions(self):
+        a = make_exception(RuntimeError, 'a')
+        b = make_exception(ValueError, 'b')
+        c = make_exception(TypeError, 'c')
+        d = make_exception(IndexError, 'd')
+        inner = make_exception(testtools.MultipleExceptions, b, c)
+
+        def run():
+            with tobiko.handle_multiple_exceptions():
+                raise testtools.MultipleExceptions(a, inner, d)
+
+        ex = self.assertRaises(RuntimeError, run)
+        self.assertEqual(a[1], ex)
+
+
+def make_exception(cls, *args, **kwargs):
+    try:
+        raise cls(*args, **kwargs)
+    except cls:
+        return sys.exc_info()