diff options
| -rw-r--r-- | src/testlib/doc/src/qttest-best-practices.qdoc | 51 | ||||
| -rw-r--r-- | src/testlib/doc/src/qttestlib-manual.qdoc | 4 |
2 files changed, 40 insertions, 15 deletions
diff --git a/src/testlib/doc/src/qttest-best-practices.qdoc b/src/testlib/doc/src/qttest-best-practices.qdoc index aa1ca76fb6..91ff87dcf5 100644 --- a/src/testlib/doc/src/qttest-best-practices.qdoc +++ b/src/testlib/doc/src/qttest-best-practices.qdoc @@ -355,24 +355,47 @@ helpful test output: \list - \li \l {Explicitly Ignore Expected Warnings} + \li \l {Test for Warnings} \li \l {Avoid Printing Debug Messages from Autotests} \li \l {Write Well-structured Diagnostic Code} \endlist - \section2 Explicitly Ignore Expected Warnings - - If a test is expected to cause Qt to output a warning or debug message - on the console, it should call \l QTest::ignoreMessage() to filter that - message out of the test output and to fail the test if the message is - not output. - - If such a message is only output when Qt is built in debug mode, use - \l QLibraryInfo::isDebugBuild() to determine whether the Qt libraries - were built in debug mode. Using \c{#ifdef QT_DEBUG} is not enough, as - it will only tell you whether the test was built in debug mode, and - that does not guarantee that the Qt libraries were also built in debug - mode. + \section2 Test for Warnings + + Just as when building your software, if test output is cluttered with + warnings you will find it harder to notice a warning that really is a clue + to the emergence of a bug. It is thus prudent to regularly check your test + logs for warnings, and other extraneous output, and investigate the + causes. When they are signs of a bug, you can make warnings trigger test + failure. + + When the code under test \e should produce messages, such as warnings + about misguided use, it is also important to test that it \e does produce + them when so used. You can test for expected messages from the code under + test, produced by \l qWarning(), \l qDebug(), \l qInfo() and friends, + using \l QTest::ignoreMessage(). This will verify that the message is + produced and filter it out of the output of the test run. If the message + is not produced, the test will fail. + + If an expected message is only output when Qt is built in debug mode, use + \l QLibraryInfo::isDebugBuild() to determine whether the Qt libraries were + built in debug mode. Using \c{#ifdef QT_DEBUG} is not enough, as it will + only tell you whether \e{the test} was built in debug mode, and that does + not guarantee that the \e{Qt libraries} were also built in debug mode. + + Your tests can (since Qt 6.3) verify that they do not trigger calls to \l + qWarning() by calling \l QTest::failOnWarnings(). This takes the warning + message to test for or a \l QRegularExpression to match against warnings; if + a matching warning is produced, it will be reported and cause the test to + fail. For example, a test that should produce no warnings at all can + \c{QTest::failOnWarnings(QRegularExpression(u".*"_s))}, which will match any + warning at all. + + You can also set the environment variable \c QT_FATAL_WARNINGS to cause + warnings to be treated as fatal errors. See \l qWarning() for details; this + is not specific to autotests. If warnings would otherwise be lost in vast + test logs, the occasional run with this environment variable set can help + you to find and eliminate any that do arise. \section2 Avoid Printing Debug Messages from Autotests diff --git a/src/testlib/doc/src/qttestlib-manual.qdoc b/src/testlib/doc/src/qttestlib-manual.qdoc index 6112d3e424..f810f2f4a3 100644 --- a/src/testlib/doc/src/qttestlib-manual.qdoc +++ b/src/testlib/doc/src/qttestlib-manual.qdoc @@ -733,7 +733,9 @@ The names of rows and columns, in a given test function's data table, should be unique: if two rows share a name, or two columns share a name, a warning - will (since Qt 6.5) be produced. + will (since Qt 6.5) be produced. See \l qWarning() for how you can cause + warnings to be treated as errors and \l {Test for Warnings} for how to get + your tests clear of other warnings. \section1 Rewriting the Test Function |