Getting strange errors using Unit tests

SGaist

Well, it looks like you have a bug somewhere in the code you are testing.

nickqu

I have a follow up question. I was able to fix the issue with the strange errors.

I developed a UI in wich a user can choose a .txt file from the system and the data will be displayed in a table widget. It data is also being processed and put in vectors.

void TravelAgency::on_actionDatei_einlesen_triggered(){
    QFile file(QFileDialog::getOpenFileName(this, tr("Open File"), "/home", tr("Text (*.txt)")));
    if (!file.exists())
        return;
    file.open(QIODevice::ReadOnly | QIODevice::Text);
    if (!file.isOpen())
        cerr << "error...";

    QTextStream stream(&file);
    QString line = stream.readLine();
    while (!line.isNull()) {
        string sLine = line.toStdString();

        fillVectors(sLine.at(0), sLine.substr(2));

        line = stream.readLine();
    }

    cout << "vector A size: " << a.size() << endl; //return a non zero value but the getter function returns 0 in the unit test.

    Test test;
    QTest::qExec(&test);
}

And lets say I have a getter Method wich simply return the size of the vector which was filled and I have the following test:

#include "test.h"

Test::Test(QObject *parent) : QObject(parent){
}

void Test::testCompany(){
    TravelAgency* t = new TravelAgency();
    int sizeA= t->getSizeOfVectorA();
    QCOMPARE(sizeA,5);
}

The test fails because the getter function returns the value 0, but I am expecting a non zero value. Am I doing something wrong?

jsulm

@nickqu said in Getting strange errors using Unit tests:

but I am expecting a non zero value

Why?
You did not fill the vector, right?

nickqu

The vector is filled correctly. It all works fine. While I was doing some debugging:

 cout << "vector A size: " << a.size() << endl;

displayed the correct size value of the vector. Before I am doing

Test test; 
QTest::qExec(&test);

But the getter simply returns 0 in the test. I don't know why...

jsulm

@nickqu Where do you fill the vector? You do not fill it in the constructor, right? And on_actionDatei_einlesen_triggered() is not called in your test.
Can you show your getter?

nickqu

No, I fill the vector in the fillVectors() function.

Is it necessary that I call on_actionDatei_einlesen_triggered() in my test? Because I am running the program and choosing a file from the .txt system. So I trigger the function which takes the .txt file processes it and fills the vector(s). And then I am exec. the test?

The getter function is simly:
``
int TravelAgency::getSizeOfVectorA(){ return a.size(); }

jsulm

@nickqu said in Getting strange errors using Unit tests:

Is it necessary that I call on_actionDatei_einlesen_triggered()

It is necessary that the vector gets filled somehow and in the test code you posted I don't see anything like that.
Where do you fill the vector in this code:

void Test::testCompany(){
    TravelAgency* t = new TravelAgency();
    int sizeA= t->getSizeOfVectorA();
    QCOMPARE(sizeA,5);
}

?

nickqu

The vectors don't get filled in the test. They get filled in te while loop in on_actionDatei_einlesen_triggered() function with the fillVectors() function.

The way that I was expecting it was this: I run the programm. The Programm Window opens. I choose a file. The while loop fills the vector(s) with the fillVectors() method.
Until now it works, because

cout << "vector A size: " << a.size() << endl;

right after the while loop, displays the correct vector size.

Now I execute the test

Test test; 
QTest::qExec(&test);

And the getter function returns the correct vector size in the test.

jsulm

@nickqu said in Getting strange errors using Unit tests:

The way that I was expecting it was this: I run the programm. The Programm Window opens. I choose a file. The while loop fills the vector(s) with the fillVectors()

This is not how unit tests work.
There should not be any interaction with users.
Why don't you simply call on_actionDatei_einlesen_triggered() in the test before checking the vector size?

nickqu

@jsulm thanks, it works now. But how can I make it, so that in the test on_actionDatei_einlesen_triggered() ist executed, when the (menu) button was clicked? Right now I get asked to choose a file as soon as the programm starts and not when the button is clicked...

jsulm

@nickqu Take a look at https://doc.qt.io/qt-5/qtest.html
There are several mousePress overloads.

nickqu

@jsulm can you make an example? I don't understand how the mousePress overloads are goingt to help me with my case.

jsulm

@nickqu Take a look at https://doc.qt.io/qt-5/qttestlib-tutorial3-example.html