PCOV

PCOV has minimal overhead compared to Xdebug, as it's a lightweight extension under 1000 lines of code focused solely on coverage, leading to faster test execution.

It works seamlessly as a drop-in replacement for Xdebug with PHPUnit's CodeCoverage library, requiring no changes to existing test suites.

When pcov.enabled=0, the extension has no performance impact, allowing it to be safely loaded in production without slowdowns.

Allows filtering by directory and exclude patterns via PCRE, enabling targeted coverage and resource optimization, as shown in the configuration options.

Provides control over arena allocation with functions like \pcov\memory(), helping users fine-tune memory usage for large test suites.