Improve std::tuple handling in tests

Currently when doing comparison with std::tuple the fallback toString
method is called which returns a Q_NULLPTR thus not allowing proper
diagnostic of the values that triggered an error. This patch
adds support for std::tuple to improve the tests output readability.

[ChangeLog][QtTest][QCOMPARE] Now outputs contents of std::tuple on
failure.

Change-Id: I046a55e2ce44c3f7728d51e4745120d38aa5e007
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/testlib/qtest.h

@@ -59,6 +59,8 @@
 #include <QtCore/qsize.h>
 #include <QtCore/qrect.h>
 
+#include <memory>
+
 QT_BEGIN_NAMESPACE
 
 
@@ -215,6 +217,25 @@ inline char *toString(const std::pair<T1, T2> &pair)
     return toString(QString::asprintf("std::pair(%s,%s)", first.data(), second.data()));
 }
 
+template <typename Tuple, int... I>
+inline char *toString(const Tuple & tuple, QtPrivate::IndexesList<I...>) {
+    using UP = std::unique_ptr<char[]>;
+    // Generate a table of N + 1 elements where N is the number of
+    // elements in the tuple.
+    // The last element is needed to support the empty tuple use case.
+    const UP data[] = {
+        UP(toString(std::get<I>(tuple)))..., UP{}
+    };
+    return formatString("std::tuple(", ")", sizeof...(I), data[I].get()...);
+}
+
+template <class... Types>
+inline char *toString(const std::tuple<Types...> &tuple)
+{
+    static const std::size_t params_count = sizeof...(Types);
+    return toString(tuple, typename QtPrivate::Indexes<params_count>::Value());
+}
+
 inline char *toString(std::nullptr_t)
 {
     return toString(QLatin1String("nullptr"));

src/testlib/qtestcase.cpp

@@ -1146,6 +1146,31 @@ void *fetchData(QTestData *data, const char *tagName, int typeId)
     return data->data(idx);
 }
 
+/*!
+ * \internal
+ */
+char *formatString(const char *prefix, const char *suffix, size_t numArguments, ...)
+{
+    va_list ap;
+    va_start(ap, numArguments);
+
+    QByteArray arguments;
+    arguments += prefix;
+
+    if (numArguments > 0) {
+        arguments += va_arg(ap, const char *);
+
+        for (size_t i = 1; i < numArguments; ++i) {
+            arguments += ", ";
+            arguments += va_arg(ap, const char *);
+        }
+    }
+
+    va_end(ap);
+    arguments += suffix;
+    return qstrdup(arguments.constData());
+}
+
 /*!
   \fn char* QTest::toHexRepresentation(const char *ba, int length)
 

src/testlib/qtestcase.h

@@ -283,6 +283,9 @@ namespace QTest
     template <typename T1, typename T2>
     inline char *toString(const std::pair<T1, T2> &pair);
 
+    template <class... Types>
+    inline char *toString(const std::tuple<Types...> &tuple);
+
     Q_TESTLIB_EXPORT char *toHexRepresentation(const char *ba, int length);
     Q_TESTLIB_EXPORT char *toPrettyCString(const char *unicode, int length);
     Q_TESTLIB_EXPORT char *toPrettyUnicode(QStringView string);
@@ -388,6 +391,8 @@ namespace QTest
     Q_TESTLIB_EXPORT bool compare_string_helper(const char *t1, const char *t2, const char *actual,
                                       const char *expected, const char *file, int line);
 
+    Q_TESTLIB_EXPORT char *formatString(const char *prefix, const char *suffix, size_t numArguments, ...);
+
 #ifndef Q_QDOC
     QTEST_COMPARE_DECL(short)
     QTEST_COMPARE_DECL(ushort)

tests/auto/testlib/selftests/expected_tuplediagnostics.lightxml

@@ -0,0 +1,34 @@
+<Environment>
+    <QtVersion>@INSERT_QT_VERSION_HERE@</QtVersion>
+    <QtBuild/>
+    <QTestVersion>@INSERT_QT_VERSION_HERE@</QTestVersion>
+</Environment>
+<TestFunction name="initTestCase">
+<Incident type="pass" file="" line="0" />
+    <Duration msecs="0"/>
+</TestFunction>
+<TestFunction name="testEmptyTuple">
+<Incident type="pass" file="" line="0" />
+    <Duration msecs="0"/>
+</TestFunction>
+<TestFunction name="testSimpleTuple">
+<Incident type="fail" file="/localqtbase/tests/auto/testlib/selftests/tuplediagnostics/tst_tuplediagnostics.cpp" line="0">
+    <Description><![CDATA[Compared values are not the same
+   Actual   (std::tuple<int>{1}): std::tuple(1)
+   Expected (std::tuple<int>{2}): std::tuple(2)]]></Description>
+</Incident>
+    <Duration msecs="0"/>
+</TestFunction>
+<TestFunction name="testTuple">
+<Incident type="fail" file="/localqtbase/tests/auto/testlib/selftests/tuplediagnostics/tst_tuplediagnostics.cpp" line="0">
+    <Description><![CDATA[Compared values are not the same
+   Actual   (tuple1): std::tuple(42, 'Y', "tuple1")
+   Expected (tuple2): std::tuple(42, 'Y', "tuple2")]]></Description>
+</Incident>
+    <Duration msecs="0"/>
+</TestFunction>
+<TestFunction name="cleanupTestCase">
+<Incident type="pass" file="" line="0" />
+    <Duration msecs="0"/>
+</TestFunction>
+<Duration msecs="0"/>

tests/auto/testlib/selftests/expected_tuplediagnostics.tap

@@ -0,0 +1,33 @@
+TAP version 13
+# tst_TupleDiagnostics
+ok 1 - initTestCase()
+ok 2 - testEmptyTuple()
+not ok 3 - testSimpleTuple()
+  ---
+  type: QCOMPARE
+  message: Compared values are not the same
+  wanted: std::tuple(2) (std::tuple<int>{2})
+  found: std::tuple(1) (std::tuple<int>{1})
+  expected: std::tuple(2) (std::tuple<int>{2})
+  actual: std::tuple(1) (std::tuple<int>{1})
+  at: tst_TupleDiagnostics::testSimpleTuple() (/localqtbase/tests/auto/testlib/selftests/tuplediagnostics/tst_tuplediagnostics.cpp:53)
+  file: /localqtbase/tests/auto/testlib/selftests/tuplediagnostics/tst_tuplediagnostics.cpp
+  line: 53
+  ...
+not ok 4 - testTuple()
+  ---
+  type: QCOMPARE
+  message: Compared values are not the same
+  wanted: std::tuple(42, 'Y', "tuple2") (tuple2)
+  found: std::tuple(42, 'Y', "tuple1") (tuple1)
+  expected: std::tuple(42, 'Y', "tuple2") (tuple2)
+  actual: std::tuple(42, 'Y', "tuple1") (tuple1)
+  at: tst_TupleDiagnostics::testTuple() (/localqtbase/tests/auto/testlib/selftests/tuplediagnostics/tst_tuplediagnostics.cpp:60)
+  file: /localqtbase/tests/auto/testlib/selftests/tuplediagnostics/tst_tuplediagnostics.cpp
+  line: 60
+  ...
+ok 5 - cleanupTestCase()
+1..5
+# tests 5
+# pass 3
+# fail 2

tests/auto/testlib/selftests/expected_tuplediagnostics.teamcity

@@ -0,0 +1,14 @@
+##teamcity[testSuiteStarted name='tst_TupleDiagnostics' flowId='tst_TupleDiagnostics']
+##teamcity[testStarted name='initTestCase()' flowId='tst_TupleDiagnostics']
+##teamcity[testFinished name='initTestCase()' flowId='tst_TupleDiagnostics']
+##teamcity[testStarted name='testEmptyTuple()' flowId='tst_TupleDiagnostics']
+##teamcity[testFinished name='testEmptyTuple()' flowId='tst_TupleDiagnostics']
+##teamcity[testStarted name='testSimpleTuple()' flowId='tst_TupleDiagnostics']
+##teamcity[testFailed name='testSimpleTuple()' message='Failure! |[Loc: /localqtbase/tests/auto/testlib/selftests/tuplediagnostics/tst_tuplediagnostics.cpp(0)|]' details='Compared values are not the same|n Actual (std::tuple<int>{1}): std::tuple(1)|n Expected (std::tuple<int>{2}): std::tuple(2)' flowId='tst_TupleDiagnostics']
+##teamcity[testFinished name='testSimpleTuple()' flowId='tst_TupleDiagnostics']
+##teamcity[testStarted name='testTuple()' flowId='tst_TupleDiagnostics']
+##teamcity[testFailed name='testTuple()' message='Failure! |[Loc: /localqtbase/tests/auto/testlib/selftests/tuplediagnostics/tst_tuplediagnostics.cpp(0)|]' details='Compared values are not the same|n Actual (tuple1): std::tuple(42, |'Y|', "tuple1")|n Expected (tuple2): std::tuple(42, |'Y|', "tuple2")' flowId='tst_TupleDiagnostics']
+##teamcity[testFinished name='testTuple()' flowId='tst_TupleDiagnostics']
+##teamcity[testStarted name='cleanupTestCase()' flowId='tst_TupleDiagnostics']
+##teamcity[testFinished name='cleanupTestCase()' flowId='tst_TupleDiagnostics']
+##teamcity[testSuiteFinished name='tst_TupleDiagnostics' flowId='tst_TupleDiagnostics']

tests/auto/testlib/selftests/expected_tuplediagnostics.txt

@@ -0,0 +1,15 @@
+********* Start testing of tst_TupleDiagnostics *********
+Config: Using QtTest library
+PASS   : tst_TupleDiagnostics::initTestCase()
+PASS   : tst_TupleDiagnostics::testEmptyTuple()
+FAIL!  : tst_TupleDiagnostics::testSimpleTuple() Compared values are not the same
+   Actual   (std::tuple<int>{1}): std::tuple(1)
+   Expected (std::tuple<int>{2}): std::tuple(2)
+   Loc: [/localqtbase/tests/auto/testlib/selftests/tuplediagnostics/tst_tuplediagnostics.cpp(0)]
+FAIL!  : tst_TupleDiagnostics::testTuple() Compared values are not the same
+   Actual   (tuple1): std::tuple(42, 'Y', "tuple1")
+   Expected (tuple2): std::tuple(42, 'Y', "tuple2")
+   Loc: [/localqtbase/tests/auto/testlib/selftests/tuplediagnostics/tst_tuplediagnostics.cpp(0)]
+PASS   : tst_TupleDiagnostics::cleanupTestCase()
+Totals: 3 passed, 2 failed, 0 skipped, 0 blacklisted, 0ms
+********* Finished testing of tst_TupleDiagnostics *********

tests/auto/testlib/selftests/expected_tuplediagnostics.xml

@@ -0,0 +1,37 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<TestCase name="tst_TupleDiagnostics">
+<Environment>
+    <QtVersion>@INSERT_QT_VERSION_HERE@</QtVersion>
+    <QtBuild/>
+    <QTestVersion>@INSERT_QT_VERSION_HERE@</QTestVersion>
+</Environment>
+<TestFunction name="initTestCase">
+<Incident type="pass" file="" line="0" />
+    <Duration msecs="0"/>
+</TestFunction>
+<TestFunction name="testEmptyTuple">
+<Incident type="pass" file="" line="0" />
+    <Duration msecs="0"/>
+</TestFunction>
+<TestFunction name="testSimpleTuple">
+<Incident type="fail" file="/localqtbase/tests/auto/testlib/selftests/tuplediagnostics/tst_tuplediagnostics.cpp" line="0">
+    <Description><![CDATA[Compared values are not the same
+   Actual   (std::tuple<int>{1}): std::tuple(1)
+   Expected (std::tuple<int>{2}): std::tuple(2)]]></Description>
+</Incident>
+    <Duration msecs="0"/>
+</TestFunction>
+<TestFunction name="testTuple">
+<Incident type="fail" file="/localqtbase/tests/auto/testlib/selftests/tuplediagnostics/tst_tuplediagnostics.cpp" line="0">
+    <Description><![CDATA[Compared values are not the same
+   Actual   (tuple1): std::tuple(42, 'Y', "tuple1")
+   Expected (tuple2): std::tuple(42, 'Y', "tuple2")]]></Description>
+</Incident>
+    <Duration msecs="0"/>
+</TestFunction>
+<TestFunction name="cleanupTestCase">
+<Incident type="pass" file="" line="0" />
+    <Duration msecs="0"/>
+</TestFunction>
+<Duration msecs="0"/>
+</TestCase>

tests/auto/testlib/selftests/expected_tuplediagnostics.xunitxml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<testsuite errors="0" failures="2" tests="5" name="tst_TupleDiagnostics">
+  <properties>
+    <property value="@INSERT_QT_VERSION_HERE@" name="QTestVersion"/>
+    <property value="@INSERT_QT_VERSION_HERE@" name="QtVersion"/>
+    <property value="" name="QtBuild"/>
+  </properties>
+  <testcase result="pass" name="initTestCase"/>
+  <testcase result="pass" name="testEmptyTuple"/>
+  <testcase result="fail" name="testSimpleTuple">
+    <failure message="Compared values are not the same
+   Actual   (std::tuple&lt;int&gt;{1}): std::tuple(1)
+   Expected (std::tuple&lt;int&gt;{2}): std::tuple(2)" result="fail"/>
+  </testcase>
+  <testcase result="fail" name="testTuple">
+    <failure message="Compared values are not the same
+   Actual   (tuple1): std::tuple(42, &apos;Y&apos;, &quot;tuple1&quot;)
+   Expected (tuple2): std::tuple(42, &apos;Y&apos;, &quot;tuple2&quot;)" result="fail"/>
+  </testcase>
+  <testcase result="pass" name="cleanupTestCase"/>
+  <system-err/>
+</testsuite>

tests/auto/testlib/selftests/selftests.pri

@@ -45,6 +45,7 @@ SUBPROGRAMS = \
      sleep \
      strcmp \
      subtest \
+     tuplediagnostics \
      verbose1 \
      verbose2 \
      verifyexceptionthrown \

tests/auto/testlib/selftests/tst_selftests.cpp

@@ -494,6 +494,7 @@ void tst_Selftests::runSubTest_data()
         << "sleep"
         << "strcmp"
         << "subtest"
+        << "tuplediagnostics"
         << "verbose1"
         << "verbose2"
 #ifndef QT_NO_EXCEPTIONS

tests/auto/testlib/selftests/tuplediagnostics/tst_tuplediagnostics.cpp

@@ -0,0 +1,65 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 Samuel Gaist <samuel.gaist@edeltech.ch>
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:GPL-EXCEPT$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+// Make sure we get a real Q_ASSERT even in release builds
+#ifdef QT_NO_DEBUG
+# undef QT_NO_DEBUG
+#endif
+
+#include <QtTest/QtTest>
+
+class tst_TupleDiagnostics: public QObject
+{
+    Q_OBJECT
+
+private slots:
+    void testEmptyTuple() const;
+    void testSimpleTuple() const;
+    void testTuple() const;
+};
+
+void tst_TupleDiagnostics::testEmptyTuple() const
+{
+    QCOMPARE(std::tuple<>{}, std::tuple<>{});
+}
+
+void tst_TupleDiagnostics::testSimpleTuple() const
+{
+    QCOMPARE(std::tuple<int>{1}, std::tuple<int>{2});
+}
+
+void tst_TupleDiagnostics::testTuple() const
+{
+    std::tuple<int, char, QString> tuple1{42, 'Y', QStringLiteral("tuple1")};
+    std::tuple<int, char, QString> tuple2{42, 'Y', QStringLiteral("tuple2")};
+    QCOMPARE(tuple1, tuple2);
+}
+
+QTEST_MAIN(tst_TupleDiagnostics)
+
+#include "tst_tuplediagnostics.moc"

tests/auto/testlib/selftests/tuplediagnostics/tuplediagnostics.pro

@@ -0,0 +1,6 @@
+SOURCES += tst_tuplediagnostics.cpp
+QT = core testlib
+
+CONFIG -= app_bundle debug_and_release_target
+
+TARGET = tuplediagnostics