Qt 4.8: QTestLib Manual

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# QTestLib Manual

The QTestLib framework, provided by Nokia, is a tool for unit testing Qt based applications and libraries. QTestLib provides all the functionality commonly found in unit testing frameworks as well as extensions for testing graphical user interfaces.

## QTestLib Features

QTestLib is designed to ease the writing of unit tests for Qt based applications and libraries:

Feature | Details
--- | ---
Lightweight | QTestLib consists of about 6000 lines of code and 60 exported symbols.
Self-contained | QTestLib requires only a few symbols from the Qt Core library for non-gui testing.
Rapid testing | QTestLib needs no special test-runners; no special registration for tests.
Data-driven testing | A test can be executed multiple times with different test data.
Basic GUI testing | QTestLib offers functionality for mouse and keyboard simulation.
Benchmarking | QTestLib supports benchmarking and provides several measurement back-ends.
IDE friendly | QTestLib outputs messages that can be interpreted by Visual Studio and KDevelop.
Thread-safety | The error reporting is thread safe and atomic.
Type-safety | Extensive use of templates prevent errors introduced by implicit type casting.
Easily extendable | Custom types can easily be added to the test data and test output.

## QTestLib API

All public methods are in the QTest namespace. In addition, the QSignalSpy class provides easy introspection for Qt's signals and slots.

## Using QTestLib

### Creating a Test

To create a test, subclass QObject and add one or more private slots to it. Each private slot is a testfunction in your test. QTest::qExec() can be used to execute all testfunctions in the test object.

In addition, there are four private slots that are not treated as testfunctions. They will be executed by the testing framework and can be used to initialize and clean up either the entire test or the current test function.

- `initTestCase()` will be called before the first testfunction is executed.
- `cleanupTestCase()` will be called after the last testfunction was executed.
- `init()` will be called before each testfunction is executed.
- `cleanup()` will be called after every testfunction.

If `initTestCase()` fails, no testfunction will be executed. If `init()` fails, the following testfunction will not be executed, the test will proceed to the next testfunction.

Example:

     class MyFirstTest: public QObject
     {
         Q_OBJECT
     private slots:
         void initTestCase()
         { qDebug("called before everything else"); }
         void myFirstTest()
         { QVERIFY(1 == 1); }
         void mySecondTest()
         { QVERIFY(1 != 2); }
         void cleanupTestCase()
         { qDebug("called after myFirstTest and mySecondTest"); }
     };

For more examples, refer to the QTestLib Tutorial.

### Building a Test

If you are using `qmake` as your build tool, just add the following to your project file:

     QT += testlib

If you are using other build tools, make sure that you add the location of the QTestLib header files to your include path (usually `include/QtTest` under your Qt installation directory). If you are using a release build of Qt, link your test to the `QtTest` library. For debug builds, use `QtTest_debug`.

See Writing a Unit Test for a step by step explanation.

### QTestLib Command Line Arguments

#### Syntax

The syntax to execute an autotest takes the following simple form:

     testname [options] [testfunctions[:testdata]]...

Substitute `testname` with the name of your executable. `testfunctions` can contain names of test functions to be executed. If no `testfunctions` are passed, all tests are run. If you append the name of an entry in `testdata`, the test function will be run only with that test data.

For example:

     /myTestDirectory$ testQString toUpper

Runs the test function called `toUpper` with all available test data.

     /myTestDirectory$ testQString toUpper toInt:zero

Runs the `toUpper` test function with all available test data, and the `toInt` test function with the testdata called `zero` (if the specified test data doesn't exist, the associated test will fail).

     /myTestDirectory$ testMyWidget -vs -eventdelay 500

Runs the testMyWidget function test, outputs every signal emission and waits 500 milliseconds after each simulated mouse/keyboard event.

#### Options

The following command line arguments are understood:

- `-help`
  outputs the possible command line arguments and give some useful help.
- `-functions`
  outputs all test functions available in the test.
- `-datatags`
  outputs all data tags available in the test. A global data tag is preceded by ' __global__ '.
- `-o` filename
  write output to the specified file, rather than to standard output
- `-silent`
  silent output, only shows warnings, failures and minimal status messages
- `-v1`
  verbose output; outputs information on entering and exiting test functions.
- `-v2`
  extended verbose output; also outputs each QCOMPARE() and QVERIFY()
- `-vs`
  outputs every signal that gets emitted
- `-xml`
  outputs XML formatted results instead of plain text
- `-lightxml`
  outputs results as a stream of XML tags
- `-xunitxml`
  outputs results as an Xunit XML document
- `-eventdelay` ms
  if no delay is specified for keyboard or mouse simulation (QTest::keyClick(), QTest::mouseClick() etc.), the value from this parameter (in milliseconds) is substituted.
- `-keydelay` ms
  like -eventdelay, but only influences keyboard simulation and not mouse simulation.
- `-mousedelay` ms
  like -eventdelay, but only influences mouse simulation and not keyboard simulation.
- `-keyevent-verbose`
  output more verbose output for keyboard simulation
- `-maxwarnings` numberBR sets the maximum number of warnings to output. 0 for unlimited, defaults to 2000.

### Creating a Benchmark

To create a benchmark, follow the instructions for creating a test and then add a QBENCHMARK macro to the test function that you want to benchmark.

     class MyFirstBenchmark: public QObject
     {
         Q_OBJECT
     private slots:
         void myFirstBenchmark()
         {
             QString string1;
             QString string2;
             QBENCHMARK {
                 string1.localeAwareCompare(string2);
             }
         }
     };

The code inside the QBENCHMARK macro will be measured, and possibly also repeated several times in order to get an accurate measurement. This depends on the selected measurement back-end. Several back-ends are available. They can be selected on the command line:

Name | Commmand-line Argument | Availability
--- | --- | ---
Walltime | (default) | All platforms
CPU tick counter | -tickcounter | Windows, Mac OS X, Linux, many UNIX-like systems.
Valgrind/Callgrind | -callgrind | Linux (if installed)
Event Counter | -eventcounter | All platforms

In short, walltime is always available but requires many repetitions to get a useful result. Tick counters are usually available and can provide results with fewer repetitions, but can be susceptible to CPU frequency scaling issues. Valgrind provides exact results, but does not take I/O waits into account, and is only available on a limited number of platforms. Event counting is available on all platforms and it provides the number of events that were received by the event loop before they are sent to their corresponding targets (this might include non-Qt events).

Note: Depending on the device configuration, Tick counters on the Windows CE platform may not be as fine-grained, compared to other platforms. Devices that do not support high-resolution timers default to one-millisecond granularity.

See the chapter 5 in the QTestLib Tutorial for more benchmarking examples.

## Using QTestLib remotely on Windows CE

`cetest` is a convenience application which helps the user to launch an application remotely on a Windows CE device or emulator.

It needs to be executed after the unit test has been successfully compiled.

Prior to launching, the following files are copied to the device:

- all Qt libraries the project links to
- QtRemote.dll
- the c runtime library specified during installation
- all files specified in the `.pro` file following the DEPLOYMENT rules.

### Using `cetest`

#### Syntax

The syntax to execute an autotest takes the following simple form:

     cetest [options] ...

#### Options

`cetest` provides the same options as those for unit-testing on non cross-compiled platforms. See Command Line Arguments for more information.

The following commands are also included:

- `-debug`
  Test version compiled in debug mode.
- `-release`
  Test version compiled in release mode.
- `-libpath` path
  Target path to copy Qt libraries to.
- `-qt-delete`
  Delete Qt libraries after execution.
- `-project-delete`
  Delete project files after execution.
- `-delete`
  Delete project and Qt libraries after execution.
- `-conf`
  Specifies a qt.conf file to be deployed to remote directory.

Note: `debug` is the default build option.

### QtRemote

`QtRemote` is a small library which is build after QTestLib. It allows the host system to create a process on a remote device and waits until its execution has been finished.

### Requirements

`cetest` uses Microsoft ActiveSync to establish a remote connection between the host computer and the device. Thus header files and libraries are needed to compile cetest and QtRemote successfully.

Prior to installation of Qt, you need to set your `INCLUDE` and `LIB` environment variables properly.

A default installation of Windows Mobile 5 for Pocket PC can be obtained by:

     set INCLUDE=C:\Program Files\Windows CE Tools\wce500\Windows Mobile 5.0 Pocket PC SDK\Activesync\Inc;%INCLUDE%
     set LIB=C:\Program Files\Windows CE Tools\wce500\Windows Mobile 5.0 Pocket PC SDK\Activesync\Lib;%LIB%

Note that Qt will remember the path, so you do not need to set it again after switching the environments for cross-compilation.

## 3rd Party Code

The CPU tick counters used for benchmarking is licensed under the following license: (from src/testlib/3rdparty/cycle.h)

Copyright (c) 2003, 2006 Matteo Frigo
Copyright (c) 2003, 2006 Massachusetts Institute of Technology

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.