testlib: Reduce JUnit test duration reporting to millisecond precision

The original Ant JUnit reporter produced test durations via Double.toString(),
supporting arbitrary precisions, and the de-facto schema declared them
as xs:decimal.

Sadly, the now popular Maven Surefire reporter limited the duration to
millisecond precision, and hard-coded this into its schema as SUREFIRE_TIME:

  https://issues.apache.org/jira/browse/SUREFIRE-1533

Unfortunately this definition spread into tools such as the Jenkins xUnit
plugin, which relies on the schema provided by Maven Surefire:

  https://issues.jenkins.io/browse/JENKINS-52152

As a result, anything that produces higher precision results will not
validate in the Jenkins xUnit plugin.

Other test frameworks have bitten the bullet and reduced their precision
correspondingly, e.g.:

 https://github.com/catchorg/Catch2/issues/2221
 https://github.com/catchorg/Catch2/commit/581c46249acf8389e9

We follow suit, and our JUnit XML output now validates against both
the Jenkins JUnit and xUnit plugins, as well as the original Apache
Ant de-facto schema.

Pick-to: 6.2
Task-number: QTBUG-95424
Change-Id: I3097d10c03c2a29709960372301b29055d224e10
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>

1 files changed, 7 insertions, 2 deletions

diff --git a/src/testlib/qjunittestlogger.cpp b/src/testlib/qjunittestlogger.cpp
index a34b431060..cac447e58f 100644
--- a/src/testlib/qjunittestlogger.cpp
+++ b/src/testlib/qjunittestlogger.cpp
@@ -77,6 +77,11 @@ static qreal elapsedTestCaseSeconds()
     return elapsedTestcaseTime.nsecsElapsed() / 1e9;
 }
 
+static QByteArray toSecondsFormat(qreal ms)
+{
+    return QByteArray::number(ms / 1000, 'f', 3);
+}
+
 void QJUnitTestLogger::startLogging()
 {
     QAbstractTestLogger::startLogging();
@@ -135,7 +140,7 @@ void QJUnitTestLogger::stopLogging()
     currentTestSuite->addAttribute(QTest::AI_Errors, buf);
 
     currentTestSuite->addAttribute(QTest::AI_Time,
-        QByteArray::number(QTestLog::msecsTotalTime() / 1000, 'f').constData());
+        toSecondsFormat(QTestLog::msecsTotalTime()).constData());
 
     currentTestSuite->addLogElement(listOfTestcases);
 
@@ -205,7 +210,7 @@ void QJUnitTestLogger::leaveTestFunction()
 void QJUnitTestLogger::leaveTestCase()
 {
     currentLogElement->addAttribute(QTest::AI_Time,
-        QByteArray::number(elapsedTestCaseSeconds(), 'f').constData());
+        toSecondsFormat(elapsedTestCaseSeconds()).constData());
 }
 
 void QJUnitTestLogger::addIncident(IncidentTypes type, const char *description,