QTimer 超时不会在单元测试中触发

Question

我正在尝试为我命名为 Counter 的 class 创建一个单元测试。这样 class 应该每 0.1 秒减少它的值 "count" ，所以我在 class 构造函数中连接了该方法。在原来的程序中一切似乎都工作得很好，但是当我尝试运行单元测试器时，它似乎没有发生连接或者 QTimer 根本没有发送超时信号。

gitHub link: https://github.com/allocro/TimerLFdP/tree/master/testCounter

Counter::Counter(QLineEdit *editSec, QLineEdit *editMin, QObject *parent) : 
QObject(parent)
{
    timer= new QTimer(this);
    [...]
    connect(timer, &QTimer::timeout, this, &Counter::decCount);
}

编辑：K，我将按照要求将其他代码部分放入此处。

在前面的代码中，这里是我要测试的class的构造函数，decCount()所做的无非是：

void Counter::decCount(){
    if (count>0)
        count--;
    else
        timer->stop();

    int countsec = count % 600;
    int countmin = (count - countsec)/600;

    QString secOut = QString::number(countsec/10) + "." 
    +QString::number(countsec%10);

    emit showCountMin(countmin);
    emit showCountSec(secOut);
}

以上信号与单元测试代码无关，它们在完整程序中使用。

现在，在tst_testCounter.cpp中，据我了解，是classic main的测试单元版本，我得到了

testCounter::testCounter() : QObject ()
{   int i;
    editSec= new QLineEdit();
    editMin= new QLineEdit();
    counter= new Counter(editSec, editMin);
    for(i=0; i<=10; i++){
        int randsec= rand() %60;
        int randmin= rand() %60;
        randsec=3;
        randmin=0; //To test the tester faster

        QString randsecString= QString::number(randsec);
        QString randminString= QString::number(randmin);


        editSec->setText(randsecString);
        editMin->setText(randminString);

        counter->set();//those are to input, they work fine, I checked
        std::cout << "Starting the Timer at " << (counter->count)/10 << 
        "sec" <<std::endl;
        counter->start(); //{timer->start();}

        while(counter->count>0){
            std::cout <<counter->count <<std::endl;
        }
        auto end= std::chrono::system_clock::now();
        counter->stop();

        auto check= std::chrono::duration_cast<std::chrono::seconds>(end - 
        start);
        int checkInt= check.count();

        if(checkInt==randsec+(randmin*60)){
            std::cout << "Timer matches" <<std::endl;
        }else{
        std::cout << "Timer doesnt match" <<std::endl;
        std::cout << "Sec counted: " << (counter->count)/10 <<std::endl;
        std::cout << "Sec passed: " << checkInt <<std::endl;
        break;
        }
    }
}

显然 .cpp 以

结尾

QTEST_MAIN(testCounter)

#include "tst_testcounter.moc"

Answer 1

首先要记住的是QTimer不是精确的，所以按秒的顺序检查会出问题，更好的测试验证以毫秒为单位的时间差小于一定的价值。

另一方面，指令：

while (counter-> count> 0) {
    std::cout << counter-> count << std::endl;
}

您没有让事件循环工作，因此 QTimer 或信号可以工作。

你应该使用的是QCoreApplication::processEvents():

while(counter.count>0){
    QCoreApplication::processEvents(QEventLoop::WaitForMoreEvents);
}

也建议测试的元素定义在方法内部，测试不在构造函数中给出，而是在槽中给出。

综合以上，并进行其他改进，得到：

counter.h

#ifndef COUNTER_H
#define COUNTER_H

#include <QObject>
class QTimer;
class QLineEdit;

class Counter : public QObject
{
    Q_OBJECT
public:
    explicit Counter(QLineEdit *setterSec, QLineEdit *setterMin, QObject *parent = nullptr);
    QTimer *timer;
    QLineEdit *setterSec;
    QLineEdit *setterMin;
    int count;
signals:
    void showCountSec(const QString &count);
    void showCountMin(int count);

public slots:
    void decCount();
    void start();
    void stop();
    void set();
};

#endif // COUNTER_H

counter.cpp

#include "counter.h"
#include <QTimer>
#include <QIntValidator>
#include <QLineEdit>

Counter::Counter(QLineEdit *editSec, QLineEdit *editMin, QObject *parent) :
    QObject(parent),
    timer(new QTimer(this)),
    setterSec(editSec),
    setterMin(editMin),
    count(0)
{
    setterSec->setValidator(new QIntValidator(0, 59, this));
    setterMin->setValidator(new QIntValidator(0, 59, this));
    connect(timer, &QTimer::timeout, this, &Counter::decCount);
}

void Counter::start(){
    timer->start(100);
}

void Counter::stop(){
    timer->stop();
}

void Counter::set(){
    timer->stop();
    count = setterSec->text().toInt()*10 + setterMin->text().toInt()*600;
    int countsec = count % 600;
    int countmin = (count - countsec)/600;

    QString secOut = QString::number(countsec/10) + "." +QString::number(countsec%10);

    emit showCountMin(countmin);
    emit showCountSec(secOut);
}

void Counter::decCount(){
    if (count > 0)
            count--;
    else
        timer->stop();

    int countsec = count % 600;
    int countmin = (count - countsec)/600;

    QString secOut = QString::number(countsec/10) + "." +QString::number(countsec%10);

    emit showCountMin(countmin);
    emit showCountSec(secOut);
}

tst_counter.h

#include <QtTest>
#include "counter.h"
#include <QLineEdit>
#include <iostream>
#include <cmath>
#include <QDebug>

// add necessary includes here

class tst_Counter : public QObject
{
    Q_OBJECT
public:
    tst_Counter();
    ~tst_Counter();

private slots:
    void initTestCD();
};

tst_Counter::tst_Counter() : QObject ()
{
}
tst_Counter::~tst_Counter()
{

}

void tst_Counter::initTestCD(){
    QLineEdit editSec;
    QLineEdit editMin;
    Counter counter(&editSec, &editMin);
    const int epsilon = 50; // ms

    for(int i=0; i<=10; i++){
        int randsec= rand() %60;
        int randmin= rand() %60;
        randsec =3;
        randmin =0; //To test the tester faster

        QString randsecString= QString::number(randsec);
        QString randminString= QString::number(randmin);


        editSec.setText(randsecString);
        editMin.setText(randminString);

        counter.set();//those are to input, they work fine, I checked
        qDebug() << "Starting the Timer at " << (counter.count)/10;

        auto start= std::chrono::system_clock::now();
        counter.start(); //{timer->start();}
        while(counter.count>0){
            QCoreApplication::processEvents(QEventLoop::WaitForMoreEvents);
        }
        auto end= std::chrono::system_clock::now();
        counter.stop();
        auto check_ms= std::chrono::duration_cast<std::chrono::milliseconds>(end - start);
        int checkInt = check_ms.count();
        int delta_s = randsec + randmin*60;
        int delta = std::abs(checkInt - delta_s);
        QVERIFY(delta < epsilon);

        qDebug() << "Sec counted: " << counter.count/10;
        qDebug() << "msec passed: " << checkInt;
    }
}

QTEST_MAIN(tst_Counter)

#include "tst_counter.moc"

输出：

********* Start testing of tst_Counter *********
Config: Using QtTest library 5.11.2, Qt 5.11.2 (x86_64-little_endian-lp64 shared (dynamic) release build; by GCC 8.2.1 20180831)
PASS   : tst_Counter::initTestCase()
QDEBUG : tst_Counter::initTestCD() Starting the Timer at  3
QDEBUG : tst_Counter::initTestCD() Sec counted:  0
QDEBUG : tst_Counter::initTestCD() msec passed:  3033
QDEBUG : tst_Counter::initTestCD() Starting the Timer at  3
QDEBUG : tst_Counter::initTestCD() Sec counted:  0
QDEBUG : tst_Counter::initTestCD() msec passed:  2999
QDEBUG : tst_Counter::initTestCD() Starting the Timer at  3
QDEBUG : tst_Counter::initTestCD() Sec counted:  0
QDEBUG : tst_Counter::initTestCD() msec passed:  3000
QDEBUG : tst_Counter::initTestCD() Starting the Timer at  3
QDEBUG : tst_Counter::initTestCD() Sec counted:  0
QDEBUG : tst_Counter::initTestCD() msec passed:  2999
QDEBUG : tst_Counter::initTestCD() Starting the Timer at  3
QDEBUG : tst_Counter::initTestCD() Sec counted:  0
QDEBUG : tst_Counter::initTestCD() msec passed:  2999
QDEBUG : tst_Counter::initTestCD() Starting the Timer at  3
QDEBUG : tst_Counter::initTestCD() Sec counted:  0
QDEBUG : tst_Counter::initTestCD() msec passed:  3000
QDEBUG : tst_Counter::initTestCD() Starting the Timer at  3
QDEBUG : tst_Counter::initTestCD() Sec counted:  0
QDEBUG : tst_Counter::initTestCD() msec passed:  2999
QDEBUG : tst_Counter::initTestCD() Starting the Timer at  3
QDEBUG : tst_Counter::initTestCD() Sec counted:  0
QDEBUG : tst_Counter::initTestCD() msec passed:  2999
QDEBUG : tst_Counter::initTestCD() Starting the Timer at  3
QDEBUG : tst_Counter::initTestCD() Sec counted:  0
QDEBUG : tst_Counter::initTestCD() msec passed:  2999
QDEBUG : tst_Counter::initTestCD() Starting the Timer at  3
QDEBUG : tst_Counter::initTestCD() Sec counted:  0
QDEBUG : tst_Counter::initTestCD() msec passed:  2999
QDEBUG : tst_Counter::initTestCD() Starting the Timer at  3
QDEBUG : tst_Counter::initTestCD() Sec counted:  0
QDEBUG : tst_Counter::initTestCD() msec passed:  2999
PASS   : tst_Counter::initTestCD()
PASS   : tst_Counter::cleanupTestCase()
Totals: 3 passed, 0 failed, 0 skipped, 0 blacklisted, 33078ms
********* Finished testing of tst_Counter *********

在下面link你可以找到完整的例子。

QTimer 超时不会在单元测试中触发

QTimer timout doesnt trigger in unit testing

c++

qt

unit-testing

qt5

qtimer