Implement QPromise<Sequence<T>>::map(mapper) (#15)

Iterate over all the promise value (i.e. `Sequence<T>`) and map the sequence to another using the given `mapper` function. Also provide a static helper to directly map values (`QtPromise::map(values, mapper)`).

tests/auto/qtpromise/helpers/helpers.pro

@@ -1,5 +1,6 @@
 TEMPLATE = subdirs
 SUBDIRS += \
     all \
+    map \
     reject \
     resolve

tests/auto/qtpromise/helpers/map/map.pro

@@ -0,0 +1,4 @@
+TARGET = tst_helpers_map
+SOURCES += $$PWD/tst_map.cpp
+
+include(../../qtpromise.pri)

tests/auto/qtpromise/helpers/map/tst_map.cpp

@@ -0,0 +1,151 @@
+// Tests
+#include "../../shared/utils.h"
+
+// QtPromise
+#include <QtPromise>
+
+// Qt
+#include <QtTest>
+
+using namespace QtPromise;
+
+class tst_helpers_map : public QObject
+{
+    Q_OBJECT
+
+private Q_SLOTS:
+    void emptySequence();
+    void modifyValues();
+    void convertValues();
+    void delayedFulfilled();
+    void delayedRejected();
+    void functorThrows();
+    void functorArguments();
+    void preserveOrder();
+    void sequenceTypes();
+};
+
+QTEST_MAIN(tst_helpers_map)
+#include "tst_map.moc"
+
+namespace {
+
+template <class Sequence>
+struct SequenceTester
+{
+    static void exec()
+    {
+        auto p = QtPromise::map(Sequence{42, 43, 44}, [](int v, ...) {
+            return QString::number(v + 1);
+        });
+
+        Q_STATIC_ASSERT((std::is_same<decltype(p), QPromise<QVector<QString>>>::value));
+        QCOMPARE(waitForValue(p, QVector<QString>()), QVector<QString>({"43", "44", "45"}));
+    }
+};
+
+} // anonymous namespace
+
+void tst_helpers_map::emptySequence()
+{
+    auto p = QtPromise::map(QVector<int>{}, [](int v, ...) {
+        return v + 1;
+    });
+
+    Q_STATIC_ASSERT((std::is_same<decltype(p), QPromise<QVector<int>>>::value));
+    QCOMPARE(waitForValue(p, QVector<int>()), QVector<int>({}));
+}
+
+void tst_helpers_map::modifyValues()
+{
+    auto p = QtPromise::map(QVector<int>{42, 43, 44}, [](int v, ...) {
+        return v + 1;
+    });
+
+    Q_STATIC_ASSERT((std::is_same<decltype(p), QPromise<QVector<int>>>::value));
+    QCOMPARE(waitForValue(p, QVector<int>()), QVector<int>({43, 44, 45}));
+}
+
+void tst_helpers_map::convertValues()
+{
+    auto p = QtPromise::map(QVector<int>{42, 43, 44}, [](int v, ...) {
+        return QString::number(v + 1);
+    });
+
+    Q_STATIC_ASSERT((std::is_same<decltype(p), QPromise<QVector<QString>>>::value));
+    QCOMPARE(waitForValue(p, QVector<QString>()), QVector<QString>({"43", "44", "45"}));
+}
+
+void tst_helpers_map::delayedFulfilled()
+{
+    auto p = QtPromise::map(QVector<int>{42, 43, 44}, [](int v, ...) {
+        return QPromise<int>([&](const QPromiseResolve<int>& resolve) {
+                QtPromisePrivate::qtpromise_defer([=]() {
+                    resolve(v + 1);
+                });
+            });
+    });
+
+    Q_STATIC_ASSERT((std::is_same<decltype(p), QPromise<QVector<int>>>::value));
+    QCOMPARE(waitForValue(p, QVector<int>()), QVector<int>({43, 44, 45}));
+}
+
+void tst_helpers_map::delayedRejected()
+{
+    auto p = QtPromise::map(QVector<int>{42, 43, 44}, [](int v, ...) {
+        return QPromise<int>([&](
+            const QPromiseResolve<int>& resolve,
+            const QPromiseReject<int>& reject) {
+                QtPromisePrivate::qtpromise_defer([=]() {
+                    if (v == 43) {
+                        reject(QString("foo"));
+                    }
+                    resolve(v);
+                });
+            });
+    });
+
+    Q_STATIC_ASSERT((std::is_same<decltype(p), QPromise<QVector<int>>>::value));
+    QCOMPARE(waitForError(p, QString()), QString("foo"));
+}
+
+void tst_helpers_map::functorThrows()
+{
+    auto p = QtPromise::map(QVector<int>{42, 43, 44}, [](int v, ...) {
+        if (v == 43) {
+            throw QString("foo");
+        }
+        return v + 1;
+    });
+
+    Q_STATIC_ASSERT((std::is_same<decltype(p), QPromise<QVector<int>>>::value));
+    QCOMPARE(waitForError(p, QString()), QString("foo"));
+}
+
+void tst_helpers_map::functorArguments()
+{
+    auto p = QtPromise::map(QVector<int>{42, 42, 42}, [](int v, int i) {
+        return v * i;
+    });
+
+    Q_STATIC_ASSERT((std::is_same<decltype(p), QPromise<QVector<int>>>::value));
+    QCOMPARE(waitForValue(p, QVector<int>()), QVector<int>({0, 42, 84}));
+}
+
+void tst_helpers_map::preserveOrder()
+{
+    auto p = QtPromise::map(QVector<int>{500, 100, 250}, [](int v, ...) {
+        return QPromise<int>::resolve(v + 1).delay(v);
+    });
+
+    Q_STATIC_ASSERT((std::is_same<decltype(p), QPromise<QVector<int>>>::value));
+    QCOMPARE(waitForValue(p, QVector<int>()), QVector<int>({501, 101, 251}));
+}
+
+void tst_helpers_map::sequenceTypes()
+{
+    SequenceTester<QList<int>>::exec();
+    SequenceTester<QVector<int>>::exec();
+    SequenceTester<std::list<int>>::exec();
+    SequenceTester<std::vector<int>>::exec();
+}

tests/auto/qtpromise/qpromise/map/map.pro

@@ -0,0 +1,4 @@
+TARGET = tst_qpromise_map
+SOURCES += $$PWD/tst_map.cpp
+
+include(../../qtpromise.pri)

tests/auto/qtpromise/qpromise/map/tst_map.cpp

@@ -0,0 +1,157 @@
+// Tests
+#include "../../shared/utils.h"
+
+// QtPromise
+#include <QtPromise>
+
+// Qt
+#include <QtTest>
+
+using namespace QtPromise;
+
+class tst_qpromise_map : public QObject
+{
+    Q_OBJECT
+
+private Q_SLOTS:
+    void emptySequence();
+    void modifyValues();
+    void convertValues();
+    void delayedFulfilled();
+    void delayedRejected();
+    void functorThrows();
+    void functorArguments();
+    void preserveOrder();
+    void sequenceTypes();
+};
+
+QTEST_MAIN(tst_qpromise_map)
+#include "tst_map.moc"
+
+namespace {
+
+template <class Sequence>
+struct SequenceTester
+{
+    static void exec()
+    {
+        auto p = QtPromise::qPromise(Sequence{42, 43, 44}).map([](int v, ...) {
+            return QString::number(v + 1);
+        }).map([](const QString& v, int i) {
+            return QtPromise::qPromise(QString("%1:%2").arg(i).arg(v));
+        }).map([](const QString& v, ...) {
+            return QtPromise::qPromise((v + "!").toUtf8());
+        }).map([](const QByteArray& v, ...) {
+            return QString::fromUtf8(v);
+        });
+
+        Q_STATIC_ASSERT((std::is_same<decltype(p), QPromise<QVector<QString>>>::value));
+        QCOMPARE(waitForValue(p, QVector<QString>()), QVector<QString>({"0:43!", "1:44!", "2:45!"}));
+    }
+};
+
+} // anonymous namespace
+
+void tst_qpromise_map::emptySequence()
+{
+    auto p = QtPromise::qPromise(QVector<int>{}).map([](int v, ...) {
+        return v + 1;
+    });
+
+    Q_STATIC_ASSERT((std::is_same<decltype(p), QPromise<QVector<int>>>::value));
+    QCOMPARE(waitForValue(p, QVector<int>()), QVector<int>({}));
+}
+
+void tst_qpromise_map::modifyValues()
+{
+    auto p = QtPromise::qPromise(QVector<int>{42, 43, 44}).map([](int v, ...) {
+        return v + 1;
+    });
+
+    Q_STATIC_ASSERT((std::is_same<decltype(p), QPromise<QVector<int>>>::value));
+    QCOMPARE(waitForValue(p, QVector<int>()), QVector<int>({43, 44, 45}));
+}
+
+void tst_qpromise_map::convertValues()
+{
+    auto p = QtPromise::qPromise(QVector<int>{42, 43, 44}).map([](int v, ...) {
+        return QString::number(v + 1);
+    });
+
+    Q_STATIC_ASSERT((std::is_same<decltype(p), QPromise<QVector<QString>>>::value));
+    QCOMPARE(waitForValue(p, QVector<QString>()), QVector<QString>({"43", "44", "45"}));
+}
+
+void tst_qpromise_map::delayedFulfilled()
+{
+    auto p = QtPromise::qPromise(QVector<int>{42, 43, 44}).map([](int v, ...) {
+        return QPromise<int>([&](const QPromiseResolve<int>& resolve) {
+                QtPromisePrivate::qtpromise_defer([=]() {
+                    resolve(v + 1);
+                });
+            });
+    });
+
+    Q_STATIC_ASSERT((std::is_same<decltype(p), QPromise<QVector<int>>>::value));
+    QCOMPARE(waitForValue(p, QVector<int>()), QVector<int>({43, 44, 45}));
+}
+
+void tst_qpromise_map::delayedRejected()
+{
+    auto p = QtPromise::qPromise(QVector<int>{42, 43, 44}).map([](int v, ...) {
+        return QPromise<int>([&](
+            const QPromiseResolve<int>& resolve,
+            const QPromiseReject<int>& reject) {
+                QtPromisePrivate::qtpromise_defer([=]() {
+                    if (v == 43) {
+                        reject(QString("foo"));
+                    }
+                    resolve(v);
+                });
+            });
+    });
+
+    Q_STATIC_ASSERT((std::is_same<decltype(p), QPromise<QVector<int>>>::value));
+    QCOMPARE(waitForError(p, QString()), QString("foo"));
+}
+
+void tst_qpromise_map::functorThrows()
+{
+    auto p = QtPromise::qPromise(QVector<int>{42, 43, 44}).map([](int v, ...) {
+        if (v == 43) {
+            throw QString("foo");
+        }
+        return v + 1;
+    });
+
+    Q_STATIC_ASSERT((std::is_same<decltype(p), QPromise<QVector<int>>>::value));
+    QCOMPARE(waitForError(p, QString()), QString("foo"));
+}
+
+void tst_qpromise_map::functorArguments()
+{
+    auto p1 = QtPromise::qPromise(QVector<int>{42, 42, 42}).map([](int v, int i) {
+        return v * i;
+    });
+
+    Q_STATIC_ASSERT((std::is_same<decltype(p1), QPromise<QVector<int>>>::value));
+    QCOMPARE(waitForValue(p1, QVector<int>()), QVector<int>({0, 42, 84}));
+}
+
+void tst_qpromise_map::preserveOrder()
+{
+    auto p = QtPromise::qPromise(QVector<int>{250, 500, 100}).map([](int v, ...) {
+        return QtPromise::qPromise(v + 1).delay(v);
+    });
+
+    Q_STATIC_ASSERT((std::is_same<decltype(p), QPromise<QVector<int>>>::value));
+    QCOMPARE(waitForValue(p, QVector<int>()), QVector<int>({251, 501, 101}));
+}
+
+void tst_qpromise_map::sequenceTypes()
+{
+    SequenceTester<QList<int>>::exec();
+    SequenceTester<QVector<int>>::exec();
+    SequenceTester<std::list<int>>::exec();
+    SequenceTester<std::vector<int>>::exec();
+}

tests/auto/qtpromise/qpromise/qpromise.pro

@@ -4,6 +4,7 @@ SUBDIRS += \
     delay \
     fail \
     finally \
+    map \
     operators \
     tap \
     tapfail \