WrapperRunner randomly throwing a Fatal Error

[dbaltas]

The error below happened on this travis build

1) PHPUnitTest::testRunWithFatalRuntimeErrorWithTheWrapperRunnerOutputsError
Failed asserting that 'PHP Catchable fatal error:  Argument 1 passed to ParaTest\Runners\PHPUnit\Worker::assign() must be an instance of ParaTest\Runners\PHPUnit\ExecutableTest, null given, called in /home/travis/build/brianium/paratest/src/ParaTest/Runners/PHPUnit/WrapperRunner.php on line 86 and defined in /home/travis/build/brianium/paratest/src/ParaTest/Runners/PHPUnit/Worker.php on line 47
PHP Stack trace:

It also happens on my dev (on around 70% of the runs) machine when running

bin/paratest -p 2 --runner WrapperRunner test/fixtures/tests/EnvironmentTest.php

[dbaltas]

Findings

When count($this->modified) (on WrapperRunner) is bigger than one, then the exception is thrown.
When count($this->modified) == 1 the test suite pass.

To reproduce

check out tripsta/paratest/issues/54-wrapper-runner-exception and run

bin/paratest -p 2 --runner WrapperRunner test/fixtures/tests/EnvironmentTest.php

Example of exception

worker count in startWorkers 2
pending count 1
modifed count 2
worker count in progressedWorkers 2
PHP Catchable fatal error: Argument 1 passed to ParaTest\Runners\PHPUnit\Worker::assign() must be an instance of ParaTest\Runners\PHPUnit\ExecutableTest, null given, called in /home/dbaltas/projects/paratest/src/ParaTest/Runners/PHPUnit/WrapperRunner.php on line 89 and defined in /home/dbaltas/projects/paratest/src/ParaTest/Runners/PHPUnit/Worker.php on line 47

Example of success

worker count in startWorkers 2
pending count 1
modifed count 1
worker count in progressedWorkers 1
modifed count 1
worker count in progressedWorkers 1
modifed count 1
worker count in progressedWorkers 1
modifed count 1
worker count in progressedWorkers 1
modifed count 1
worker count in progressedWorkers 1
modifed count 1
worker count in progressedWorkers 1
modifed count 1
worker count in progressedWorkers 1
modifed count 1
worker count in progressedWorkers 1
..

Time: 0 seconds, Memory: 3.25Mb

OK (2 tests, 6 assertions)

[giorgiosironi]

Thank you for the investigation, since it can be reproduced I'll try to fix
this issue.

[dbaltas]

@giorgiosironi Is the above fix OK?
Also this issue still persists in last builds of master in travis 118,121, even though it passed on 119 with the same code as 121,

1) PerformanceTest::testRunningSuitesWithLongBootstrapsIsFasterWithTheWrapperRunner
Symfony\Component\Process\Exception\RuntimeException: The process timed-out.

[giorgiosironi]

Yes, the fix is ok as this is a race condition between $this->pending and "more workers than pending tests" being available in a single shot. I'll look at master and see if I can reproduce the issue.

[giorgiosironi]

I'll download a 5.3 VM to get the same problem.

[giorgiosironi]

Reproduced on 5.3.10, with a similar test. Symfony/Process has a default timeout of 60 seconds for a process (don't know between which events it is measured), and that stops the suite.
PHP 5.3 is nototiously slower than 5.4, so that's probably why it is happening only in that environment.

[giorgiosironi]

I got a green build here:
https://travis-ci.org/giorgiosironi/paratest
and the identical commit failing on 5.3 here:
https://travis-ci.org/brianium/paratest

[dbaltas]

Its OK. Thumbs up!