Fatal error: Uncaught TypeError: ParaTest\Logging\LogInterpreter::mergeReaders

[caherrera]

Q	A
ParaTest version	6.11.1
PHPUnit version	9.6.29
PHP version	8.4.5, 8.3.10

Summary

Fatal TypeError in LogInterpreter::mergeReaders when generating a JUnit report for a file with zero tests.

Current behavior

When running ParaTest with the --log-junit option on a test file that results in "0 tests, 0 assertions", it throws a fatal error instead of generating the report.

PHP Fatal error: Uncaught TypeError: ParaTest\Logging\LogInterpreter::mergeReaders(): Return value must be of type ParaTest\Logging\JUnit\TestSuite, null returned in /var/www/html/vendor/brianium/paratest/src/Logging/LogInterpreter.php:93

How to reproduce: command, code and error stack trace

1. Create a PHPUnit test file that contains no actual tests (or is empty), for example ./tests/Unit/SissueUnitTest.php.
2. Run ParaTest with the --log-junit flag targeting that specific file.
3. The following command will trigger the error:

./vendor/bin/paratest --processes=4 --testdox --log-junit=results.xml ./tests/Unit/SissueUnitTest.php
Full error stack trace:

ParaTest v6.11.1 upon PHPUnit 9.6.29 by Sebastian Bergmann and contributors.

Time: 00:00.113, Memory: 36.65 MB

OK (0 tests, 0 assertions)
PHP Fatal error:  Uncaught TypeError: ParaTest\Logging\LogInterpreter::mergeReaders(): Return value must be of type ParaTest\Logging\JUnit\TestSuite, null returned in /var/www/html/vendor/brianium/paratest/src/Logging/LogInterpreter.php:93
Stack trace:
#0 /var/www/html/vendor/brianium/paratest/src/Logging/JUnit/Writer.php(61): ParaTest\Logging\LogInterpreter->mergeReaders()
#1 /var/www/html/vendor/brianium/paratest/src/Logging/JUnit/Writer.php(86): ParaTest\Logging\JUnit\Writer->getXml()
#2 /var/www/html/vendor/brianium/paratest/src/Runners/PHPUnit/BaseRunner.php(162): ParaTest\Logging\JUnit\Writer->write()
#3 /var/www/html/vendor/brianium/paratest/src/Runners/PHPUnit/BaseRunner.php(133): ParaTest\Runners\PHPUnit\BaseRunner->log()
#4 /var/www/html/vendor/brianium/paratest/src/Runners/PHPUnit/BaseRunner.php(82): ParaTest\Runners\PHPUnit\BaseRunner->complete()
#5 /var/www/html/vendor/brianium/paratest/src/Console/Commands/ParaTestCommand.php(102): ParaTest\Runners\PHPUnit\BaseRunner->run()
#6 /var/www/html/vendor/symfony/console/Command/Command.php(326): ParaTest\Console\Commands\ParaTestCommand->execute()
#7 /var/www/html/vendor/symfony/console/Application.php(1078): Symfony\Component\Console\Command\Command->run()
#8 /var/www/html/vendor/symfony/console/Application.php(324): Symfony\Component\Console\Application->doRunCommand()
#9 /var/www/html/vendor/symfony/console/Application.php(175): Symfony\Component\Console\Application->doRun()
#10 /var/www/html/vendor/brianium/paratest/bin/paratest(37): Symfony\Component\Console\Application->run()
#11 /var/www/html/vendor/bin/paratest(119): include('...')
#12 {main}
  thrown in /var/www/html/vendor/brianium/paratest/src/Logging/LogInterpreter.php on line 93

Expected behavior

ParaTest should not throw a fatal error when running against a test file that contains zero tests. It should generate a valid, possibly empty, JUnit XML report file (results.xml) and exit gracefully.

[github-actions]

This issue has gone two months without activity. In another two weeks, I will close it.

But! If you comment or otherwise update it, I will reset the clock, and if you label it Backlog or In Progress, I will leave it alone ... forever!