QTestEventLoop: stop when the test fails

It makes no sense for the event loop of a test to keep running after a
test has failed. This lets test code simply use the usual testlib
macros to compare and verify values in asynchronous tests that would
otherwise need to hand-test values and send a signal on failure (that
the main test can connect to an event-loops quit() or equivalent).

For example, QLocalSocket's benchmark simply uses the usual macros,
without doing anything to stop its event loop if they fail, with the
sad result that, when a test fails, it does so repeatedly and then
times out, causing the test program to be killed without running later
tests. With this change, that test code (once converted to use
QTestEventLoop) is able to exit gracefully on the first failure.

[ChangeLog][QtTest][QTestEventLoop] The QTestEventLoop new exits its
event loop as soon as the test is known to be failing.

Task-number: QTBUG-91713
Change-Id: If0d455741668722034906763025dda496d2afbb4
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

2 files changed, 8 insertions, 4 deletions

diff --git a/src/testlib/qtesteventloop.h b/src/testlib/qtesteventloop.h
index d576de4267..10bb4f3f96 100644
--- a/src/testlib/qtesteventloop.h
+++ b/src/testlib/qtesteventloop.h
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2021 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the QtTest module of the Qt Toolkit.
@@ -41,6 +41,7 @@
 #define QTESTEVENTLOOP_H
 
 #include <QtTest/qttestglobal.h>
+#include <QtTest/qtestcase.h>
 
 #include <QtCore/qcoreapplication.h>
 #include <QtCore/qeventloop.h>
@@ -93,11 +94,12 @@ private:
 inline void QTestEventLoop::enterLoopMSecs(int ms)
 {
     Q_ASSERT(!loop);
-
-    QEventLoop l;
-
     _timeout = false;
 
+    if (QTest::currentTestFailed())
+        return;
+
+    QEventLoop l;
     timerId = startTimer(ms);
 
     loop = &l;
diff --git a/src/testlib/qtestresult.cpp b/src/testlib/qtestresult.cpp
index 7498b92024..581e8bc33b 100644
--- a/src/testlib/qtestresult.cpp
+++ b/src/testlib/qtestresult.cpp
@@ -46,6 +46,7 @@
 #include <QtTest/qtestdata.h>
 #include <QtTest/qtestcase.h>
 #include <QtTest/qtestassert.h>
+#include <QtTest/qtesteventloop.h>
 
 #include <stdlib.h>
 #include <stdio.h>
@@ -464,6 +465,7 @@ bool QTestResult::compare(bool success, const char *failureMsg,
 void QTestResult::addFailure(const char *message, const char *file, int line)
 {
     clearExpectFail();
+    QTestEventLoop::instance().exitLoop();
 
     if (QTest::blacklistCurrentTest)
         QTestLog::addBFail(message, file, line);