Chore: Upgrade PHPUnit to 12, modernize tests, refresh Rector sets

[loks0n]

Summary

• Upgrade phpunit/phpunit ^9.5 → ^12.0, phpstan/phpstan ^2.0 → ^2.1, rector/rector ^2.0 → ^2.4 (all pulling the current latest).
• Expand Rector with the PHPUnit 10/11/12, code-quality, and annotations-to-attributes sets; drop three dead skip entries; skip AssertEmptyNullableObjectToAssertInstanceofRector which weakens assertNull.
• Run the refactor (adds declare(strict_types=1) to tests, finalizes test classes, converts the @dataProvider to a generator, assertEquals → assertSame where inferable) and sweep remaining assertEquals(null|true|false, …) and literal-expected cases manually.
• Migrate phpunit.xml to the PHPUnit 12 schema and exclude the BaseTest trait file and the misnamed UtopiaFPMRequestTest mock helper from the unit suite (both previously produced runner warnings).

Noteworthy fixes surfaced by stricter assertions

• RequestTest::testCanRemoveHeaders asserted assertEquals(null, getHeader(...)), which only passed via null == '' loose equality — getHeader is typed string. Now assertSame('', …).
• RouteTest::testCanSetAndGetAction compared two different closures with assertEquals — replaced with assertInstanceOf(\Closure::class, …), which is what the test actually meant.

Test plan

• composer analyze (PHPStan level 7) clean
• composer refactor:check (Rector dry-run) clean
• composer format:check (Pint) clean
• vendor/bin/phpunit --testsuite unit — 84 tests, 248 assertions, all pass
• e2e suites (e2e-fpm, e2e-swoole) — require docker fixtures, not run locally; CI should exercise them

🤖 Generated with Claude Code

[github-actions]

k6 benchmark

Throughput	Requests	Fail rate	p50	p95
5490 req/s	384358	0%	7.51 ms	15.54 ms

[greptile-apps]

Greptile Summary

This PR upgrades PHPUnit 9 → 12, PHPStan 2.0 → 2.1, and Rector 2.0 → 2.4, then applies the resulting automated and manual test modernisation: declare(strict_types=1), final classes, #[DataProvider] attributes, and assertEquals → assertSame conversions throughout. The PHPUnit 12 schema, suite exclusions, and Rector skip-list are all handled correctly.

• P1 — tests/ResponseTest.php testCanAddCookie: The "cookie case insensitive" block assigns to PHP array copies ($result->getCookies()['cookiename']['name'] = ...) which are immediately discarded, so the case-normalisation behaviour is silently never verified.

Confidence Score: 4/5

Safe to merge after addressing the dead-assignment bug in testCanAddCookie that leaves cookie case-normalisation completely untested.

One P1 finding: the cookie case-insensitive test block in ResponseTest.php mutates throwaway array copies instead of asserting, meaning the case-normalisation path is never exercised. The remaining findings are P2 style (assertEquals → assertSame completeness in HttpTest and the e2e suite).

tests/ResponseTest.php — testCanAddCookie dead-assignment block (lines 70–73)

Important Files Changed

Filename	Overview
tests/ResponseTest.php	Migrated to final class, strict_types, assertSame for fluent return values — but the cookie case-insensitive block (lines 72–73) contains dead assignments instead of assertions, silently leaving the case normalization behavior unverified.
tests/HttpTest.php	Migrated to final class, strict_types, @dataProvider → #[DataProvider] attribute, and most assertEquals → assertSame; one assertEquals on JSON strings remains on line 682.
tests/RequestTest.php	Migrated cleanly: strict_types, final class, assertEquals(null) → assertSame('') fix for getHeader after removeHeader.
tests/RouteTest.php	Migrated cleanly: strict_types, final class, two-closure assertEquals replaced with assertInstanceOf(Closure::class) + behavioral assertion.
tests/e2e/ResponseFPMTest.php	Gets strict_types and final class; five assertEquals calls on string cookie values remain unconverted to assertSame.
phpunit.xml	Migrated to PHPUnit 12 schema with xsi:noNamespaceSchemaLocation; BaseTest.php and UtopiaFPMRequestTest.php correctly excluded from unit suite to suppress runner warnings.
rector.php	Expanded with PHPUnit 10/11/12 sets, code-quality, and annotations-to-attributes; dead skips removed; AssertEmptyNullableObjectToAssertInstanceofRector correctly skipped with rationale.
composer.json	Bumps phpunit ^9.5 → ^12.0, phpstan ^2.0 → ^2.1, rector ^2.0 → ^2.4 as intended.

Comments Outside Diff (1)

1. tests/ResponseTest.php, line 70-73 (link)

   The "test cookie case insensitive" block assigns to throwaway array copies rather than asserting anything. In PHP, getCookies() returns an array by value, so writing to $result->getCookies()['cookiename']['name'] modifies a temporary copy that is immediately discarded. The case-insensitive storage of cookieName → cookiename is never actually verified.

_{Reviews (3): Last reviewed commit: "Chore: Add PHPUnit schema reference, tig..." | Re-trigger Greptile}