paratest

Project Overview: ParaTest

ParaTest is an innovative tool designed to facilitate parallel testing in PHPUnit, a popular unit testing framework for PHP. This means that instead of running tests one after the other, they can be executed simultaneously, which can significantly decrease the time it takes to ensure software quality. ParaTest integrates seamlessly with existing PHPUnit tests, requiring no extra setup or configuration, making it an easy upgrade to any testing process.

Key Benefits

• Zero Configuration Needed: Once installed, you can instantly run tests in parallel using ParaTest. By simply executing vendor/bin/paratest, tests can be parallelized by TestCase. Alternatively, use vendor/bin/paratest --functional to parallelize by Test.
• Integrated Code Coverage Reports: ParaTest combines code coverage outputs from multiple parallel processes into a single, comprehensive report, helping developers understand their code's test coverage more effectively.

Installing ParaTest

Installing ParaTest is straightforward through Composer, a PHP package manager. Execute the following command to include ParaTest as a development dependency in your project:

composer require --dev brianium/paratest

Supported Versions

ParaTest is optimized to work with the latest version of PHPUnit. This ensures compatibility and takes advantage of the latest improvements and optimizations in both PHP and PHPUnit, reducing bugs and maintenance efforts.

Usage and Configuration

After installation, you can find the ParaTest binary at vendor/bin/paratest. Access all available options by running it with the --help option. Here are a few important features:

• Test Token: ParaTest provides a TEST_TOKEN environment variable that is unique to each running test. This can be useful for using separate databases in parallel test executions.
• Code Coverage with PCOV and xDebug: ParaTest supports popular code coverage tools like PCOV and xDebug. These need to be configured properly to work with ParaTest, enabling effective test coverage measurement even in parallel execution environments.

Best Practices for Setup

When running tests in parallel, traditional initialization practices may not work as expected with PHPUnit. Instead, use a shared file system as shown below to synchronize initialization across multiple test processes:

static bool $initialized = false;

public function setUp(): void
{
    if (! self::$initialized) {
        touch('/tmp/test-initialization-lock-file');
        $lockFile = fopen('/tmp/test-initialization-lock-file', 'r');

        if (flock($lockFile, LOCK_EX | LOCK_NB)) {
            self::initialize();
        } else {
            flock($lockFile, LOCK_SH);
        }

        self::$initialized = true;
    }
}

Troubleshooting

If issues arise while running ParaTest, enhanced debugging information can be obtained by executing tests with --verbose --debug options. This helps diagnose issues by displaying detailed output and subprocess failures.

Caveats and Limitations

ParaTest does not support some constants, static methods, and variables due to current limitations in the WrapperRunner implementation. Developers should ensure any shared code is not within the test classes themselves.

Integration with PHPStorm

ParaTest can be integrated with PHPStorm, a widely used IDE for PHP development, to enhance the testing workflow. By setting up a dedicated ParaTest configuration, tests can be run parallelly within the IDE, complete with code coverage analysis. This setup allows developers to leverage PHPStorm's powerful features like rerunning failed tests and toggling automated tests seamlessly with ParaTest.

Contributing to ParaTest

For those interested in enhancing ParaTest, it's important to run comprehensive checks using the make command before submitting contributions. This ensures that any additions or changes maintain the robustness and reliability of the tool.

ParaTest stands out as a reliable tool for PHP developers, offering significant time savings and improving the efficiency of test processes by leveraging parallel processing—an essential component for high-velocity software development environments.