Remove usage of `debug_backtrace()` to check presence of `Factories` trait

[nikophil]

debug_backtrace() is known to harm performances.... see

foundry/src/Exception/FactoriesTraitNotUsed.php

Line 36 in 2d28e67

$backTrace = \debug_backtrace(\DEBUG_BACKTRACE_IGNORE_ARGS); // @phpstan-ignore ekinoBannedCode.function

[Amoifr]

I had a look at this one. Two findings that may change what you want done.

Where it costs. The call sits in Configuration::instance(), so it runs on every factory operation rather than once per test. A counter over the main suite reaches 1125 calls, and that is a floor: my local setup is sqlite only, with 383 tests skipped.

Why it is not a straight swap. The question the backtrace answers is "does the test class I am being called from use the trait". hasMethod('_beforeHook') is the cheap half; finding the class is the expensive half. tests/Integration/ForceFactoriesTraitUsage/ pins three things that make it hard:

• a base class using the trait counts for its children;
• pulling .zenstruck_foundry.configuration from the container must stay silent, while Object1Factory::createOne() must deprecate;
• tracking who called Configuration::boot() does not work either, since those tests boot it themselves, exactly like the trait does.

And PHPUnit only exposes the current test class through an extension, which is precisely the case where this check is already skipped.

What I would suggest instead: memoize the positive case only. While one configuration is booted, once a KernelTestCase using the trait has been found in the stack the answer cannot change, and Configuration::shutdown() already runs between tests. That turns one backtrace per factory call into one per test. The negative case keeps checking every time on purpose: caching "no KernelTestCase in the stack" would wrongly silence a later call coming from a test class without the trait in the same boot.

It does not delete the call, it takes it off the hot path. Given the trait and this check both go away in 3.0, that may be the right amount of effort, but it is your call. Happy to send that, or something else if you had a different removal in mind.