phpunit-naughtytestdetector

"Naughty test detector" for PHPUnit. Identifies tests leaving garbage after themselves.

Many of us have been there - your integration test works in isolation, but breaks when running in a sequence of tests. This can be very difficult to troubleshoot, but luckily phpunit-naughtytestdetector is here to help.

Requirements

• PHPUnit 6.0+
• Supported PHP versions: 7.0 and 7.1

Note: for older PHPUnit or PHP 5.6, use v0.2.0.

Installation

NaughtyTestDetector is installable via Composer and should be added as a require-dev dependency:

composer require --dev petrkotek/phpunit-naughtytestdetector

Usage

1. Enable NaughtyTestListener by adding the following to your test suite's phpunit.xml file:

<phpunit bootstrap="vendor/autoload.php">
    ...
    <listeners>
        <listener class="PetrKotek\NaughtyTestDetector\PHPUnit\Listeners\NaughtyTestListener">
            <arguments>
                <!-- Class name of your own MetricFetcher -->
                <string>MyProject\TestUtils\MyMetricFetcher</string>
                <!-- Optional constructor arguments for the metric fetcher -->
                <array>
                    <element>
                        <string>hello world</string>
                    </element>
                </array>
                <!-- Optionally specify levels on which MetricFetcher should be executed -->
                <!-- Note: values below are the default ones -->
                <array>
                    <element key="executeOnTestLevel">
                        <boolean>false</boolean>
                    </element>
                    <element key="executeOnTestSuiteLevel">
                        <boolean>true</boolean>
                    </element>                
                    <element key="executeOnGlobalLevel">
                        <boolean>false</boolean>
                    </element>
                </array>
            </arguments>
        </listener>
    </listeners>
</phpunit>

2. Implement the MetricFetcher interface, e.g.:

namespace MyProject\TestUtils\MyMetricFetcher;

use PetrKotek\NaughtyTestDetector\MetricFetcher;

class MyMetricFetcher implements MetricFetcher
{
    private $db;
    
    public function __construct()
    {
        $this->db = mysqli_connect("127.0.0.1", "my_user", "my_password", "my_db");
    }

    /**
     * @return array
     */
    public function fetchMetrics()
    {
        $result = mysqli_query($this->db, 'SELECT COUNT * FROM my_table');
        $row = mysqli_fetch_row($result);
        
        return ['records' => $row[0];
    }
}

Tip: You can also use built-in metric fetcher, e.g. PetrKotek\NaughtyTestDetector\MetricFetchers\GlobalsMetricFetcher.

3. Run your test suite.

E.g. phpunit --configuration integration.xml

NaughtyTestListener will fetch metrics before & after each TestSuite (aka "test class") and if there is a difference between before & after, it prints out like message like this:

MyProject\Integration\MyNamespace\BadTest is naughty!
 - my_table: 0 -> 5 (+5)

This means, that before the test, there was 0 records in the my_table and after executing all the tests, there were 5 records.

Note: If you want to temporarily disable Naughty Test Detector, use DISABLE_NAUGHTY_TEST_DETECTOR enviromental variable, e.g. DISABLE_NAUGHTY_TEST_DETECTOR=1 phpunit --configuration integration.xml.