Today I was running my tests and had a failing test:

Tests\Common\BusinessLogic\XXX\XXLogicTest::testInvalidXX with data set #9 ([['dsadsa', 'dsafsdfsd', 1234.23, -1234.23, '', 'dsadsa']]) Failed asserting that 1 matches expected 0.

/var/www/html/tests/Common/BusinessLogic/Asfalistiko/FormSectionELogicTest.php:102 /var/www/html/tests/Common/BusinessLogic/XXX/XXLogicTest.php:301

I tried to debug the issue, but I had a lot of data in my dataset. The failing case was only with a specific dataset and I needed to run the failing test testInvalidXX with only the soecific one (dataset #9).

In order to do this I've launched the phpunit like this:

./vendor/bin/phpunit ./tests/Common/BusinessLogic/XXX/XXLogicTest.php --filter="testInvalidXX#9"

In the command above, pay attention to the --filter value provided. The filter value is:

testInvalidXX#9

The filter value is consisted of 2 parts:

1. The test name testInvalidXX
2. The dataset index #9

By using this filter, PHPUnit will only run the specified test case with the dataset index #9, allowing you to focus on debugging the specific failure.

This tutorial should help you run a specific test with a particular dataset index using PHPUnit.