Support PHPUnit 13

Summary

PHPUnit 13 was released on February 6, 2026. Pest 4.x currently pins to phpunit/phpunit ^12.5.8 with a conflict on >12.5.8, preventing PHPUnit 13 installation.

Analysis

I audited Pest's source for usage of all PHPUnit 13 removed APIs:

• Assert::isType(), assertContainsOnly(), containsOnly() — not used by Pest
• testClassName() on hook events — Pest only uses this on BeforeFirstTestMethodErrored/AfterLastTestMethodErrored, which retain the method in PHPUnit 13
• Configuration::includeTestSuite()/excludeTestSuite() — not used
• #[RunClassInSeparateProcess], --dont-report-useless-tests — not used

All internal APIs Pest depends on (TextUI\Application, Configuration\Registry, TestResult\Facade, CliArguments\Builder, etc.) retain their namespaces and method signatures in PHPUnit 13.

Pest's runtime code appears to be fully compatible with PHPUnit 13.

Blocker

nunomaduro/collision ^8.8.3 (a Pest runtime dependency) conflicts with phpunit/phpunit >=13.0.0. Collision PR #342 tracks PHPUnit 13 support there, but it's blocked because collision's CI uses Pest (which doesn't support PHPUnit 13 yet) — a circular dependency.

PR

I've submitted PR #1629 to widen the constraint. This breaks the circular dependency from the Pest side, allowing collision to update independently.

Start by reviewing the PHPUnit constraint described in the issue and PR #1629, then verify the documented PHPUnit 13 compatibility analysis. Done means Pest can install with PHPUnit 13 without the current constraint or Collision conflict; check the linked Collision PR and relevant dependency resolution before making any change.