Merge pull request #2547 from matrix-org/rav/test_make_deferred_yieldable

Add some tests for make_deferred_yieldable

1 files changed, 134 insertions, 0 deletions

diff --git a/tests/util/test_logcontext.py b/tests/util/test_logcontext.py
new file mode 100644
index 0000000000..e2f7765f49
--- /dev/null
+++ b/tests/util/test_logcontext.py
@@ -0,0 +1,134 @@
+import twisted.python.failure
+from twisted.internet import defer
+from twisted.internet import reactor
+from .. import unittest
+
+from synapse.util.async import sleep
+from synapse.util import logcontext
+from synapse.util.logcontext import LoggingContext
+
+
+class LoggingContextTestCase(unittest.TestCase):
+
+    def _check_test_key(self, value):
+        self.assertEquals(
+            LoggingContext.current_context().test_key, value
+        )
+
+    def test_with_context(self):
+        with LoggingContext() as context_one:
+            context_one.test_key = "test"
+            self._check_test_key("test")
+
+    @defer.inlineCallbacks
+    def test_sleep(self):
+        @defer.inlineCallbacks
+        def competing_callback():
+            with LoggingContext() as competing_context:
+                competing_context.test_key = "competing"
+                yield sleep(0)
+                self._check_test_key("competing")
+
+        reactor.callLater(0, competing_callback)
+
+        with LoggingContext() as context_one:
+            context_one.test_key = "one"
+            yield sleep(0)
+            self._check_test_key("one")
+
+    def _test_preserve_fn(self, function):
+        sentinel_context = LoggingContext.current_context()
+
+        callback_completed = [False]
+
+        @defer.inlineCallbacks
+        def cb():
+            context_one.test_key = "one"
+            yield function()
+            self._check_test_key("one")
+
+            callback_completed[0] = True
+
+        with LoggingContext() as context_one:
+            context_one.test_key = "one"
+
+            # fire off function, but don't wait on it.
+            logcontext.preserve_fn(cb)()
+
+            self._check_test_key("one")
+
+        # now wait for the function under test to have run, and check that
+        # the logcontext is left in a sane state.
+        d2 = defer.Deferred()
+
+        def check_logcontext():
+            if not callback_completed[0]:
+                reactor.callLater(0.01, check_logcontext)
+                return
+
+            # make sure that the context was reset before it got thrown back
+            # into the reactor
+            try:
+                self.assertIs(LoggingContext.current_context(),
+                              sentinel_context)
+                d2.callback(None)
+            except BaseException:
+                d2.errback(twisted.python.failure.Failure())
+
+        reactor.callLater(0.01, check_logcontext)
+
+        # test is done once d2 finishes
+        return d2
+
+    def test_preserve_fn_with_blocking_fn(self):
+        @defer.inlineCallbacks
+        def blocking_function():
+            yield sleep(0)
+
+        return self._test_preserve_fn(blocking_function)
+
+    def test_preserve_fn_with_non_blocking_fn(self):
+        @defer.inlineCallbacks
+        def nonblocking_function():
+            with logcontext.PreserveLoggingContext():
+                yield defer.succeed(None)
+
+        return self._test_preserve_fn(nonblocking_function)
+
+    @defer.inlineCallbacks
+    def test_make_deferred_yieldable(self):
+        # a function which retuns an incomplete deferred, but doesn't follow
+        # the synapse rules.
+        def blocking_function():
+            d = defer.Deferred()
+            reactor.callLater(0, d.callback, None)
+            return d
+
+        sentinel_context = LoggingContext.current_context()
+
+        with LoggingContext() as context_one:
+            context_one.test_key = "one"
+
+            d1 = logcontext.make_deferred_yieldable(blocking_function())
+            # make sure that the context was reset by make_deferred_yieldable
+            self.assertIs(LoggingContext.current_context(), sentinel_context)
+
+            yield d1
+
+            # now it should be restored
+            self._check_test_key("one")
+
+    @defer.inlineCallbacks
+    def test_make_deferred_yieldable_on_non_deferred(self):
+        """Check that make_deferred_yieldable does the right thing when its
+        argument isn't actually a deferred"""
+
+        with LoggingContext() as context_one:
+            context_one.test_key = "one"
+
+            d1 = logcontext.make_deferred_yieldable("bum")
+            self._check_test_key("one")
+
+            r = yield d1
+            self.assertEqual(r, "bum")
+            self._check_test_key("one")