How to add tests to an existing project?

SGaist

Hi,

Depending on how the project is structured you may have to move some stuff aground.

In any case, there's often a dedicated tests subfolder than will contain more subfolders to keep your test code cleanly separated.

jkwok678

Should I be adding the test code to my current classes?
Or should I be using the autotest project?
If I wanted to test my Window class method called convertMilesToMetres, should I do it this way with an auto test project?

#include "window.h
class WindowTest: public QObject
{
    Q_OBJECT

private:
  
private slots:
    void initTestCase()
    {
       Window win = new Window;
    }

    void testConverter()
    {
        QCOMPARE(win.convertMilesToMetres(1), 1600); // compare two values
    }

};

QTEST_MAIN(WindowTest)
#include "windowtest.moc"

VRonin

@jkwok678 said in How to add tests to an existing project?:

Should I be adding the test code to my current classes?

No, generally it's a bad idea. You could add special members that are needed for tests (e.g. getter methods for intermediate results you want to test) inside #ifdef blocks so you can exclude them in the deployed builds

Or should I be using the autotest project?

Yes, even more than one

If I wanted to test my Window class method called convertMilesToMetres, should I do it this way with an auto test project?

There is nothing magical inside tests, they are just normal C++ functions, treat them as such:

#include "window.h"
class WindowTest : public QObject
{
    Q_OBJECT
private slots:
    void testConverter()
    {
        Window win;
        QCOMPARE(win.convertMilesToMetres(1), 1600); // compare two values
    }
};
QTEST_MAIN(WindowTest)
#include "windowtest.moc"

jkwok678

@VRonin
Even with this example.
If I make a new Auto test project with this

There is nothing magical inside tests, they are just normal C++ functions, treat them as such:

#include "window.h"
class WindowTest : public QObject
{
    Q_OBJECT
private slots:
    void testConverter()
    {
        Window win;
        QCOMPARE(win.convertMilesToMetres(1), 1600); // compare two values
    }
};
QTEST_MAIN(WindowTest)
#include "windowtest.moc"

How can I run it with Cmake on build?

Also does it make sense to maybe not make a auto test poject, and just create a .cpp file with the exact same methods inside instead?

Christian Ehrlicher

@jkwok678 said in How to add tests to an existing project?:

How can I run it with Cmake on build?

You don't run autotests on build but afterwards with e.g. 'make test' or in a jenkins job.
See also CMake documentation about add_test()

jkwok678

@Christian-Ehrlicher
Hmm, so what exactly would I need to start automated testing?
Coming from a Java and JUnit background, all I had to do was make a test class, and I could create a test configuration and run that and all the tests in the test class would run whenever I liked. Is this possible with Qt Test?

VRonin

If your are using CMake, the workflow is:

call cmake
- this crates the makefile/projectfile that the compiler/linker can digest
call make (cmake --build . for convenience)
- to actually build the projects
call ctest
- this will run the tests that you added with add_test(). You can run specific tests by specifying the -r name_of_the_test argument

jkwok678

@VRonin
Am I able to run any test I want at any time?
E.g. All of the unit tests or just 1 of them ?
Is it doable like Java and Junit in the Intelij IDE?
What I mean is that the IDE has good support for JUnit, where I can click a button close to where I set breakpoints and run that particular test.
Also would just 1 test project be enough be multiple cpp test files?
It seems a little messy in terms of project structure to have 1 auto test project for each class/file?

I imagined my test structure to be a little like

MyProject/tests/QtTests/

And inside here I can have a windowTest.cpp, canvasTest.cpp andmapTest.cpp. Along with a CMakeLists.txt.
But when I tried to create mutltiple test projects, it's more like

MyProject/tests/QtTests/WidowClassTest
MyProject/tests/QtTests/CanvasClassTest
MyProject/tests/QtTests/MapClassTest

Each with their own ___Test.cpp and a CMakeLists.txt.
Is the 2nd way of doing things better?

VRonin

@jkwok678 said in How to add tests to an existing project?:

E.g. All of the unit tests or just 1 of them ?
Is it doable like Java and Junit in the Intelij IDE?

In Qt Creator in the top left corner expand the combobox that says "projects" and select tests to run them

What I mean is that the IDE has good support for JUnit, where I can click a button close to where I set breakpoints and run that particular test.

No as far as I'm aware

It seems a little messy in terms of project structure to have 1 auto test project for each class/file?
Is the 2nd way of doing things better?

Qt Test is designed to be used 1-project-per-test. You can build around it but, believe me, the results are sub-par.

But when I tried to create mutltiple test projects, it's more like
MyProject/tests/QtTests/WidowClassTest
MyProject/tests/QtTests/CanvasClassTest
MyProject/tests/QtTests/MapClassTest

Folder structure has nothing to do with projects.
To test classes Window, Canvas and Map, you can create a folder structure like:

MyProject
- tests
  - tst_window.cpp
  - tst_canvas.cpp
  - tst_map.cpp
  - CMakeLists.txt

and the content of CMakeLists.txt would be:

cmake_minimum_required(VERSION 3.9)
find_package(QT NAMES Qt6 Qt5 COMPONENTS Core Test REQUIRED)
find_package(Qt${QT_VERSION_MAJOR} COMPONENTS Core Test Gui Widgets REQUIRED)

macro(BasicTest TestName)
    set(targetName "tst_${TestName}")
    set(testProjectName "tst${TestName}")
    string(TOLOWER ${TestName} TestSourceFileName)
    add_executable(${targetName} "tst_${TestSourceFileName}.cpp")
    target_include_directories(${targetName} PRIVATE ${CMAKE_CURRENT_SOURCE_DIR} ${CMAKE_CURRENT_BINARY_DIR})
    target_link_libraries(${targetName} PRIVATE Qt${QT_VERSION_MAJOR}::Core Qt${QT_VERSION_MAJOR}::Test Qt${QT_VERSION_MAJOR}::Gui Qt${QT_VERSION_MAJOR}::Widgets)
    set_target_properties(${targetName} PROPERTIES
        AUTOMOC ON
        AUTOUIC ON
        AUTORCC ON
        CXX_STANDARD 11
        CXX_STANDARD_REQUIRED ON
    )
    add_test(NAME ${testProjectName} WORKING_DIRECTORY "${CMAKE_BINARY_DIR}" COMMAND $<TARGET_FILE:${targetName}>)
endmacro()

BasicTest(Window)
BasicTest(Canvas)
BasicTest(Map)

To add more tests just add 1 line at the end

jkwok678

@VRonin said in How to add tests to an existing project?:

BasicTest(Window)

What's that?
Is that the class name in tst_window.cpp?

VRonin

@jkwok678 said in How to add tests to an existing project?:

What's that?

BasicTest is the macro defined in the code snippet

@VRonin said in How to add tests to an existing project?:

To test classes Window, Canvas and Map

jkwok678

@VRonin
So is what you said earlier, with 1 test project, and 3 test files optimal?
MyProject - tests - tst_window.cpp, tst_map.cpp, tst_canvas.cpp

VRonin

@jkwok678 said in How to add tests to an existing project?:

So is what you said earlier, with 1 test project, and 3 test files optimal?

This is not 1 test project. 1 CMakeLists.txt can create multiple projects, in this case I'm creating 1 project for each class to test, I'm just doing it in a single CMakeLists.txt file

jkwok678

@VRonin
So everytime I want to test another class, I should create a new autotest project with Qt Creator?
If it's not what would the process be if I wanted to test more than 1 class?

VRonin

@jkwok678 said in How to add tests to an existing project?:

So everytime I want to test another class, I should create a new autotest project with Qt Creator?

No. Say you now want to test the class MyClass. You'd add the file MyProject/tests/tst_myclass.cpp and append BasicTest(MyClass) to the snippet pasted above

jkwok678

@VRonin
Ah, So it's like 1 auto test project when I start testing, and when I want to test more classes, just add a new MyClass.cpp file and add it to CmakeList?

VRonin

@jkwok678 Conceptually yes (Stackoverflow would say no because the technical terms you used are not very precise but high-level you got the concept)

P.S.
If you don't want unnecessary pain in the future with cross-platform support, keep your .c/.cpp/.h,/.hpp etc files lower-case only

jkwok678

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