qtquicktest-index.qdoc

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// Copyright (C) 2018 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GFDL-1.3-no-invariants-only
 
/*!
    \page qtquicktest-index.html
    \title Qt Quick Test
    \brief Unit testing framework for QML.
 
    \target Introduction to Qt Quick Test
    \section1 Introduction
 
    \l {Qt Quick Test QML Types}{Qt Quick Test} is a unit test framework for QML applications.
    Test cases are written as JavaScript functions within a \l [QML] TestCase
    type:
 
    \qml
    import QtQuick 2.3
    import QtTest 1.0
 
    TestCase {
        name: "MathTests"
 
        function test_math() {
            compare(2 + 2, 4, "2 + 2 = 4")
        }
 
        function test_fail() {
            compare(2 + 2, 5, "2 + 2 = 5")
        }
    }
    \endqml
 
    Functions whose names start with \c{test_} are treated as test cases
    to be executed. See the documentation for the \l [QML] TestCase and
    \l [QML] SignalSpy types for more information on writing test cases.
 
    \note There is no binary compatibility guarantee for the Qt Quick Test
          module. This means that an application that uses Qt Quick Test is
          only guaranteed to work with the Qt version it was developed against.
          However, source compatibility is guaranteed.
 
    \section1 Using the Module
 
    \section2 QML API
 
    The QML types in Qt Quick Test are available through the \c QtTest import.
    To use the types, add the following import statement to your .qml file:
 
    \qml
    import QtTest
    \endqml
 
    \section2 C++ API
 
    Using the \l{Qt Quick Test C++ API}{C++ API} requires linking against the
    module library, either directly or through other dependencies. Several
    build tools have dedicated support for this, including
    \l{CMake Documentation}{CMake} and \l{qmake}.
 
    \section3 Building with CMake
 
    Use the \c find_package() command to locate the needed module components in
    the Qt6 package:
 
    \snippet overview.cmake cmake_use
 
    See also the \l{Build with CMake} overview.
 
    \section3 Building with qmake
 
    There are two ways to link against the corresponding C++ library. If your
    test project uses a QML \l TestCase, you should already have the following
    line in your project file:
 
    \badcode
    CONFIG += qmltestcase
    \endcode
 
    This will cause the test to link to the C++ \QtQuickTest library.
 
    If you have a C++-only test project, you can add the following line
    to your project file:
 
    \badcode
    QT += qmltest
    \endcode
 
    \target Running Qt Quick Tests
    \section1 Running Tests
 
    Test cases are launched by a C++ harness that consists of
    the following code:
 
    \snippet src_qmltest_qquicktest_snippet.cpp 1
 
    Where "example" is the identifier to use to uniquely identify
    this set of tests. Finally, add \c{CONFIG += qmltestcase} to the project
    file:
 
    \badcode
    TEMPLATE = app
    TARGET = tst_example
    CONFIG += warn_on qmltestcase
    SOURCES += tst_example.cpp
    \endcode
 
    The test harness scans the specified source directory recursively
    for "tst_*.qml" files. If \c{QUICK_TEST_SOURCE_DIR} is not defined,
    then the current directory will be scanned when the harness is run.
    Other *.qml files may appear for auxillary QML components that are
    used by the test.
 
    The \c{-input} command-line option can be set at runtime to run
    test cases from a different directory. This may be needed to run
    tests on a target device where the compiled-in directory name refers
    to a host. For example:
 
    \badcode
    tst_example -input /mnt/SDCard/qmltests
    \endcode
 
    It is also possible to run a single file using the \c{-input} option.
    For example:
 
    \badcode
    tst_example -input data/test.qml
    \endcode
 
    \badcode
    tst_example -input <full_path>/test.qml
    \endcode
 
    \note Specifying the full path to the qml test file is for example
    needed for shadow builds.
 
    If your test case needs QML imports, then you can add them as
    \c{-import} options to the test program command-line.
 
    If \c IMPORTPATH is specified in your .pro file, each import path added to \c IMPORTPATH
    will be passed as a command-line argument when the test is run using "make check":
 
    \badcode
    IMPORTPATH += $$PWD/../imports/my_module1 $$PWD/../imports/my_module2
    \endcode
 
    The \c{-functions} command-line option will return a list of the current
    tests functions. It is possible to run a single test function using the name
    of the test function as an argument. For example:
 
    \badcode
    tst_example Test_Name::function1
    \endcode
 
    The \c{-help} command-line option will return all the options available.
 
    \badcode
    tst_example -help
    \endcode
 
    \note Running a Qt Quick test case will always show a window on the screen,
    even if the test code doesn't involve any Quick UI. To avoid that, run the
    test executable with \c {-platform offscreen}.
 
    \section1 Executing C++ Before QML Tests
 
    To execute C++ code before any of the QML tests are run, the
    \l QUICK_TEST_MAIN_WITH_SETUP macro can be used. This can be useful for
    setting context properties on the QML engine, amongst other things.
 
    The macro is identical to \c QUICK_TEST_MAIN, except that it takes an
    additional \c QObject* argument. The test framework will call slots and
    invokable functions with the following names:
 
    \table
        \header
            \li Name
            \li Purpose
            \li Since
        \row
            \li \c {void applicationAvailable()}
            \li Called right after the QApplication object was instantiated.
                Use this function to perform setup that does not require a
                \l QQmlEngine instance.
            \li Qt 5.12
        \row
            \li \c {void qmlEngineAvailable(QQmlEngine *)}
            \li Called when the QML engine is available.
                Any \l {QQmlEngine::addImportPath}{import paths},
                \l {QQmlEngine::addPluginPath}{plugin paths},
                and \l {QQmlFileSelector::setExtraSelectors}{extra file selectors}
                will have been set on the engine by this point.
 
                This function is called once for each QML test file,
                so any arguments are unique to that test. For example, this
                means that each QML test file will have its own QML engine.
 
                This function can be used to \l {Choosing the Correct Integration
                Method Between C++ and QML}{register QML types} and
                \l {QQmlEngine::addImportPath()}{add import paths},
                amongst other things.
            \li Qt 5.11
        \row
            \li \c {void cleanupTestCase()}
            \li Called right after the test execution has finished.
                Use this function to clean up before everything will start to be destructed.
            \li Qt 5.12
    \endtable
 
    The following example demonstrates how the macro can be used to set context
    properties on the QML engine:
 
    \snippet src_qmltest_qquicktest.cpp 2
 
    The \c .moc include is based on the file name of the \c .cpp file.
    For example, in the example above, the \c .cpp file is named
    \c src_qmltest_qquicktest.cpp. If the file was named \c MyTest.cpp, the include would
    be:
 
    \code
    #include "MyTest.moc"
    \endcode
 
    \section1 Reference
 
    \list
      \li \l{Qt Quick Test QML Types}{QML Types}
      \li \l{Qt Quick Test C++ API}{C++ API}
    \endlist
 
    \section1 Licenses
 
    Qt Quick Tests is available under commercial licenses from \l{The Qt Company}.
    In addition, it is available under free software licenses. Since Qt 5.4,
    these free software licenses are
    \l{GNU Lesser General Public License, version 3}, or
    the \l{GNU General Public License, version 2}.
    See \l{Qt Licensing} for further details.
*/