From 6d6e7288fe0200353740e03e6218a2781342f3e4 Mon Sep 17 00:00:00 2001 From: Richard van der Hoff Date: Mon, 21 May 2018 16:49:59 +0100 Subject: Stop the transaction cache caching failures The transaction cache has some code which tries to stop it caching failures, but if the callback function failed straight away, then things would happen backwards and we'd end up with the failure stuck in the cache. --- tests/rest/client/test_transactions.py | 54 ++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) (limited to 'tests/rest/client') diff --git a/tests/rest/client/test_transactions.py b/tests/rest/client/test_transactions.py index d7cea30260..b650a7772b 100644 --- a/tests/rest/client/test_transactions.py +++ b/tests/rest/client/test_transactions.py @@ -2,6 +2,8 @@ from synapse.rest.client.transactions import HttpTransactionCache from synapse.rest.client.transactions import CLEANUP_PERIOD_MS from twisted.internet import defer from mock import Mock, call + +from synapse.util.logcontext import LoggingContext from tests import unittest from tests.utils import MockClock @@ -39,6 +41,58 @@ class HttpTransactionCacheTestCase(unittest.TestCase): # expect only a single call to do the work cb.assert_called_once_with("some_arg", keyword="arg", changing_args=0) + @defer.inlineCallbacks + def test_does_not_cache_exceptions(self): + """Checks that, if the callback throws an exception, it is called again + for the next request. + """ + called = [False] + + def cb(): + if called[0]: + # return a valid result the second time + return defer.succeed(self.mock_http_response) + + called[0] = True + raise Exception("boo") + + with LoggingContext("test") as test_context: + try: + yield self.cache.fetch_or_execute(self.mock_key, cb) + except Exception as e: + self.assertEqual(e.message, "boo") + self.assertIs(LoggingContext.current_context(), test_context) + + res = yield self.cache.fetch_or_execute(self.mock_key, cb) + self.assertEqual(res, self.mock_http_response) + self.assertIs(LoggingContext.current_context(), test_context) + + @defer.inlineCallbacks + def test_does_not_cache_failures(self): + """Checks that, if the callback returns a failure, it is called again + for the next request. + """ + called = [False] + + def cb(): + if called[0]: + # return a valid result the second time + return defer.succeed(self.mock_http_response) + + called[0] = True + return defer.fail(Exception("boo")) + + with LoggingContext("test") as test_context: + try: + yield self.cache.fetch_or_execute(self.mock_key, cb) + except Exception as e: + self.assertEqual(e.message, "boo") + self.assertIs(LoggingContext.current_context(), test_context) + + res = yield self.cache.fetch_or_execute(self.mock_key, cb) + self.assertEqual(res, self.mock_http_response) + self.assertIs(LoggingContext.current_context(), test_context) + @defer.inlineCallbacks def test_cleans_up(self): cb = Mock( -- cgit 1.4.1