Fail unit tests that leave messages sitting around undrained.

Tests might be accidentally forgetting to drain their messages, and
hence think messages got delivered when they did not.  Fail the tests
if that happens.

Fixes #17624

src/app/tests/TestReadInteraction.cpp

@@ -306,7 +306,7 @@ class TestReadInteraction
     static void TestSubscribeEarlyShutdown(nlTestSuite * apSuite, void * apContext);
     static void TestSubscribeInvalidAttributePathRoundtrip(nlTestSuite * apSuite, void * apContext);
     static void TestReadInvalidAttributePathRoundtrip(nlTestSuite * apSuite, void * apContext);
-    static void TestSubscribeInvalidIterval(nlTestSuite * apSuite, void * apContext);
+    static void TestSubscribeInvalidInterval(nlTestSuite * apSuite, void * apContext);
     static void TestReadShutdown(nlTestSuite * apSuite, void * apContext);
     static void TestResubscribeRoundtrip(nlTestSuite * apSuite, void * apContext);
     static void TestSubscribeRoundtripStatusReportTimeout(nlTestSuite * apSuite, void * apContext);
@@ -411,6 +411,12 @@ void TestReadInteraction::TestReadClient(nlTestSuite * apSuite, void * apContext
     err = readClient.SendRequest(readPrepareParams);
     NL_TEST_ASSERT(apSuite, err == CHIP_NO_ERROR);
 
+    // We don't actually want to deliver that message, because we want to
+    // synthesize the read response.  But we don't want it hanging around
+    // forever either.
+    ctx.GetLoopback().mNumMessagesToDrop = 1;
+    ctx.DrainAndServiceIO();
+
     GenerateReportData(apSuite, apContext, buf, false /*aNeedInvalidReport*/, true /* aSuppressResponse*/);
     err = readClient.ProcessReportData(std::move(buf));
     NL_TEST_ASSERT(apSuite, err == CHIP_NO_ERROR);
@@ -545,6 +551,12 @@ void TestReadInteraction::TestReadClientInvalidReport(nlTestSuite * apSuite, voi
     err = readClient.SendRequest(readPrepareParams);
     NL_TEST_ASSERT(apSuite, err == CHIP_NO_ERROR);
 
+    // We don't actually want to deliver that message, because we want to
+    // synthesize the read response.  But we don't want it hanging around
+    // forever either.
+    ctx.GetLoopback().mNumMessagesToDrop = 1;
+    ctx.DrainAndServiceIO();
+
     GenerateReportData(apSuite, apContext, buf, true /*aNeedInvalidReport*/, true /* aSuppressResponse*/);
 
     err = readClient.ProcessReportData(std::move(buf));
@@ -1992,7 +2004,7 @@ void TestReadInteraction::TestReadShutdown(nlTestSuite * apSuite, void * apConte
     Platform::Delete(pClients[2]);
 }
 
-void TestReadInteraction::TestSubscribeInvalidIterval(nlTestSuite * apSuite, void * apContext)
+void TestReadInteraction::TestSubscribeInvalidInterval(nlTestSuite * apSuite, void * apContext)
 {
     TestContext & ctx = *static_cast<TestContext *>(apContext);
     CHIP_ERROR err    = CHIP_NO_ERROR;
@@ -2553,6 +2565,11 @@ void TestReadInteraction::TestPostSubscribeRoundtripChunkReportTimeout(nlTestSui
     NL_TEST_ASSERT(apSuite, engine->GetNumActiveReadClients() == 0);
     engine->Shutdown();
     NL_TEST_ASSERT(apSuite, ctx.GetExchangeManager().GetNumActiveExchanges() == 0);
+
+    // Engine shutdown seems to trigger some messages to try to be sent.  Make
+    // sure those get flushed out.
+    ctx.DrainAndServiceIO();
+
     ctx.CreateSessionBobToAlice();
 }
 } // namespace app
@@ -2593,10 +2610,9 @@ const nlTest sTests[] =
     NL_TEST_DEF("TestSubscribeEarlyShutdown", chip::app::TestReadInteraction::TestSubscribeEarlyShutdown),
     NL_TEST_DEF("TestSubscribeInvalidAttributePathRoundtrip", chip::app::TestReadInteraction::TestSubscribeInvalidAttributePathRoundtrip),
     NL_TEST_DEF("TestReadInvalidAttributePathRoundtrip", chip::app::TestReadInteraction::TestReadInvalidAttributePathRoundtrip),
-    NL_TEST_DEF("TestSubscribeInvalidIterval", chip::app::TestReadInteraction::TestSubscribeInvalidIterval),
+    NL_TEST_DEF("TestSubscribeInvalidInterval", chip::app::TestReadInteraction::TestSubscribeInvalidInterval),
     NL_TEST_DEF("TestSubscribeRoundtripStatusReportTimeout", chip::app::TestReadInteraction::TestSubscribeRoundtripStatusReportTimeout),
     NL_TEST_DEF("TestPostSubscribeRoundtripStatusReportTimeout", chip::app::TestReadInteraction::TestPostSubscribeRoundtripStatusReportTimeout),
-    //#if 0
     NL_TEST_DEF("TestReadChunkingStatusReportTimeout", chip::app::TestReadInteraction::TestReadChunkingStatusReportTimeout),
     NL_TEST_DEF("TestSubscribeRoundtripChunkStatusReportTimeout", chip::app::TestReadInteraction::TestSubscribeRoundtripChunkStatusReportTimeout),
     NL_TEST_DEF("TestPostSubscribeRoundtripChunkStatusReportTimeout", chip::app::TestReadInteraction::TestPostSubscribeRoundtripChunkStatusReportTimeout),

src/app/tests/TestReportingEngine.cpp

@@ -158,6 +158,9 @@ void TestReportingEngine::TestBuildAndSendSingleReportData(nlTestSuite * apSuite
     app::ReadHandler readHandler(dummy, exchangeCtx, chip::app::ReadHandler::InteractionType::Read);
     readHandler.OnInitialRequest(std::move(readRequestbuf));
     err = InteractionModelEngine::GetInstance()->GetReportingEngine().BuildAndSendSingleReportData(&readHandler);
+
+    ctx.DrainAndServiceIO();
+
     NL_TEST_ASSERT(apSuite, err == CHIP_NO_ERROR);
 }
 

src/transport/raw/tests/NetworkTestHelpers.h

@@ -74,10 +74,9 @@ class LoopbackTransport : public Transport::Base
     void InitLoopbackTransport(System::Layer * systemLayer) { mSystemLayer = systemLayer; }
     void ShutdownLoopbackTransport()
     {
-        // TODO: remove these after #17624 (Ensure tests drain all message in loopback transport) being fixed
-        // Packets are allocated from platform memory, we should release them before Platform::MemoryShutdown
-        while (!mPendingMessageQueue.empty())
-            mPendingMessageQueue.pop();
+        // Make sure no one left packets hanging out that they thought got
+        // delivered but actually didn't.
+        VerifyOrDie(mPendingMessageQueue.empty());
     }
 
     /// Transports are required to have a constructor that takes exactly one argument