Qt Test is a framework for unit testing Qt based applications and libraries. Qt Test provides all the functionality commonly found in unit testing frameworks as well as extensions for testing graphical user interfaces.
Qt Test is designed to ease the writing of unit tests for Qt based applications and libraries:
| 特征 | 细节 |
|---|---|
| Lightweight | Qt Test consists of about 6000 lines of code and 60 exported symbols. |
| Self-contained | Qt Test requires only a few symbols from the Qt Core module for non-gui testing. |
| Rapid testing | Qt Test 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 | Qt Test offers functionality for mouse and keyboard simulation. |
| 基准测试 | Qt Test supports benchmarking and provides several measurement back-ends. |
| IDE friendly | Qt Test outputs messages that can be interpreted by Qt Creator, 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. |
You can use a Qt Creator wizard to create a project that contains Qt tests and build and run them directly from Qt Creator. For more information, see 运行自动测试 .
To create a test, subclass QObject and add one or more private slots to it. Each private slot is a test function in your test. QTest::qExec () can be used to execute all test functions in the test object.
In addition, you can define the following private slots that are not treated as test functions. When present, 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 test function is executed.
initTestCase_data()
will be called to create a global test data table.
cleanupTestCase()
will be called after the last test function was executed.
init()
will be called before each test function is executed.
cleanup()
will be called after every test function.
使用
initTestCase()
for preparing the test. Every test should leave the system in a usable state, so it can be run repeatedly. Cleanup operations should be handled in
cleanupTestCase()
, so they get run even if the test fails.
使用
init()
for preparing a test function. Every test function should leave the system in a usable state, so it can be run repeatedly. Cleanup operations should be handled in
cleanup()
, so they get run even if the test function fails and exits early.
Alternatively, you can use RAII (resource acquisition is initialization), with cleanup operations called in destructors, to ensure they happen when the test function returns and the object moves out of scope.
若
initTestCase()
fails, no test function will be executed. If
init()
fails, the following test function will not be executed, the test will proceed to the next test function.
范例：
class MyFirstTest: public QObject { Q_OBJECT private: bool myCondition() { return true; } private slots: void initTestCase() { qDebug("Called before everything else."); } void myFirstTest() { QVERIFY(true); // check that a condition is satisfied QCOMPARE(1, 1); // compare two values } void mySecondTest() { QVERIFY(myCondition()); QVERIFY(1 != 2); } void cleanupTestCase() { qDebug("Called after myFirstTest and mySecondTest."); } };
Finally, if the test class has a static public
void initMain()
method, it is called by the
QTEST_MAIN
macros before the
QApplication
object is instantiated. This was added in 5.14.
For more examples, refer to the Qt Test 教程 .
You can build an executable that contains one test class that typically tests one class of production code. However, usually you would want to test several classes in a project by running one command.
见 编写单元测试 for a step by step explanation.
可以使用
采用 CMake 和 CTest 构建
to create a test.
CTest
enables you to include or exclude tests based on a regular expression that is matched against the test name. You can further apply the
LABELS
property to a test and CTest can then include or exclude tests based on those labels. All labeled targets will be run when
test
target is called on the command line.
注意：
On Android, if you have one connected device or emulator, tests will run on that device. If you have more than one device connected, set the environment variable
ANDROID_DEVICE_SERIAL
到
ADB serial number
of the device that you want to run tests on.
There are several other advantages with CMake. For example, the result of a test run can be published on a web server using CDash with virtually no effort.
CTest scales to very different unit test frameworks, and works out of the box with QTest .
The following is an example of a CMakeLists.txt file that specifies the project name and the language used (here, mytest and C++), the Qt modules required for building the test (Qt5Test), and the files that are included in the test ( tst_mytest.cpp ).
project(mytest LANGUAGES CXX) find_package(Qt6 COMPONENTS Test REQUIRED) set(CMAKE_INCLUDE_CURRENT_DIR ON) set(CMAKE_AUTOMOC ON) enable_testing(true) add_executable(mytest tst_mytest.cpp) add_test(NAME mytest COMMAND mytest) target_link_libraries(mytest PRIVATE Qt::Test)
For more information about the options you have, see 构建采用 CMake .
If you are using
qmake
as your build tool, just add the following to your project file:
QT += testlib
If you would like to run the test via
make check
, add the additional line:
CONFIG += testcase
To prevent the test from being installed to your target, add the additional line:
CONFIG += no_testcase_installs
见
qmake manual
for more information about
make check
.
If you are using other build tools, make sure that you add the location of the Qt Test 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
.
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.
例如：
/myTestDirectory$ testQString toUpper
Runs the test function called
toUpper
with all available test data.
/myTestDirectory$ testQString toUpper toInt:zero
运行
toUpper
test function with all available test data, and the
toInt
test function with the test data called
zero
(if the specified test data doesn't exist, the associated test will fail).
/myTestDirectory$ testMyWidget -vs -eventdelay 500
运行
testMyWidget
function test, outputs every signal emission and waits 500 milliseconds after each simulated mouse/keyboard event.
The following command line options determine how test results are reported:
-o
filename,format
txt
,
xml
,
lightxml
,
junitxml
or
tap
). The special filename
-
may be used to log to standard output.
-o
filename
-txt
-xml
-lightxml
-junitxml
-csv
-teamcity
-tap
The first version of the
-o
option may be repeated in order to log test results in multiple formats, but no more than one instance of this option can log test results to standard output.
If the first version of the
-o
option is used, neither the second version of the
-o
option nor the
-txt
,
-xml
,
-lightxml
,
-teamcity
,
-junitxml
or
-tap
options should be used.
If neither version of the
-o
option is used, test results will be logged to standard output. If no format option is used, test results will be logged in plain text.
The following command line options control how much detail is reported in test logs:
-silent
-v1
-v2
-v1
for plain text output.)
-vs
The following command-line options influence how tests are run:
-functions
-datatags
-eventdelay
ms
-keydelay
ms
-mousedelay
ms
-maxwarnings
number
-nocrashhandler
-platform
name
The following command line options control benchmark testing:
-callgrind
-tickcounter
-eventcounter
-minimumvalue
n
-minimumtotal
n
-iterations
n
-median
n
-vb
-help
You can set certain environment variables in order to affect the execution of an autotest:
QTEST_DISABLE_CORE_DUMP
QTEST_DISABLE_STACK_DUMP
QTEST_FATAL_FAIL
To create a benchmark, follow the instructions for creating a test and then add a QBENCHMARK macro or QTest::setBenchmarkResult () to the test function that you want to benchmark. In the following code snippet, the macro is used:
class MyFirstBenchmark: public QObject { Q_OBJECT private slots: void myFirstBenchmark() { QString string1; QString string2; QBENCHMARK { string1.localeAwareCompare(string2); } } };
A test function that measures performance should contain either a single
QBENCHMARK
macro or a single call to
setBenchmarkResult()
. Multiple occurrences make no sense, because only one performance result can be reported per test function, or per data tag in a data-driven setup.
Avoid changing the test code that forms (or influences) the body of a
QBENCHMARK
macro, or the test code that computes the value passed to
setBenchmarkResult()
. Differences in successive performance results should ideally be caused only by changes to the product you are testing. Changes to the test code can potentially result in misleading report of a change in performance. If you do need to change the test code, make that clear in the commit message.
In a performance test function, the
QBENCHMARK
or
setBenchmarkResult()
should be followed by a verification step using
QCOMPARE
(),
QVERIFY
(), and so on. You can then flag a performance result as
invalid
if another code path than the intended one was measured. A performance analysis tool can use this information to filter out invalid results. For example, an unexpected error condition will typically cause the program to bail out prematurely from the normal program execution, and thus falsely show a dramatic performance increase.
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:
| 名称 | 命令行自变量 | 可用性 |
|---|---|---|
| Walltime | (默认) | 所有平台 |
| CPU tick counter | -tickcounter | Windows、macOS、Linux、许多像 Unix 的系统。 |
| Event Counter | -eventcounter | 所有平台 |
| Valgrind Callgrind | -callgrind | Linux (若有安装) |
| Linux Perf | -perf | Linux |
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).
The Linux Performance Monitoring solution is available only on Linux and provides many different counters, which can be selected by passing an additional option
-perfcounter countername
，譬如
-perfcounter cache-misses
,
-perfcounter branch-misses
，或
-perfcounter l1d-load-misses
. The default counter is
cpu-cycles
. The full list of counters can be obtained by running any benchmark executable with the option
-perfcounterlist
.
见 编写基准测试 in the Qt Test Tutorial for more benchmarking examples.
You can define
initTestCase_data()
to set up a global test data table. Each test is run once for each row in the global test data table. When the test function itself
is data-driven
, it is run for each local data row, for each global data row. So, if there are
g
rows in the global data table and
d
rows in the test's own data-table, the number of runs of this test is
g
times
d
.
Global data is fetched from the table using the QFETCH_GLOBAL () 宏。
The following are typical use cases for global test data:
For example, to test each number provided by
roundTripInt_data()
with each locale provided by
initTestCase_data()
:
void TestQLocale::roundTripInt() { QFETCH_GLOBAL(QLocale, locale); QFETCH(int, number); bool ok; QCOMPARE(locale.toInt(locale.toString(number), &ok), number); QVERIFY(ok); }