Display deprecation stacktrace

[nikophil]

Hello,

sometimes finding where a deprecation comes from could be challenging. I think a mechanism in PHPUnit which displays the stack trace of deprecations would be helpful.

In Symfony, they've solved it by the following: if the SYMFONY_DEPRECATIONS_HELPER is a regex (I guess, they detect it if the var starts and ends with a /, or something like this), they break PHPUnit execution when the first deprecation resolving this regex is found, and the stack trace is printed.
see https://symfony.com/doc/current/components/phpunit_bridge.html#display-the-full-stack-trace

I'm not sure that breaking the execution is the best solution, but at least, it prevents for giant outputs if the test suite is full of deprecations.

I would be willing to contribute for this, but I'm not sure of how this should work. Do you see any other more elegant solution for this? Maybe we can add a new option which would display the stack traces, or at least write them in a file in order to not pollute the output?

thanks!

[soyuka]

Indeed, we see that there's the first line of the stack trace, for example:

1) src/GraphQl/Type/SchemaBuilder.php:38
blabla

Triggered by:

* ApiPlatform\Tests\Functional\BackedEnumPropertyTest::testGraphQl
  Functional/BackedEnumPropertyTest.php:55

But when using the trigger_deprecation helper from Symfony, all you see is vendor/symfony/deprecation-contracts/function.php:25. Not sure how to fix that on the PHPUnit TextUI as it has no verbose mode.

I'm not a huge fan of the SYMFONY_DEPRECATIONS_HELPER flag it's complicated to program and isn't quite user-friendly.

[nikophil]

maybe just a flag like --display-deprecation-with-stack would be enough

[sebastianbergmann]

Did you configure Symfony's trigger_deprecation() function as a deprecation trigger (see #5689 (comment) and https://docs.phpunit.de/en/11.3/configuration.html#the-deprecationtrigger-element) with PHPUnit?

[nikophil]

nope, I didn't know about this configuration, and I think it will be the solution. Thanks!

what about to detect the existence of such triggers to automatically register the main known ones?

[nikophil]

hum, it seems that it does not work as I expected: deprecationTriggers seems to be only involved in the decision whether the deprecation is self/direct/indirect.

Something nice, would be to use these trigger deprecation in order to display the real place where the deprecation was triggered.

meaning, instead of having this:

1 tests triggered 1 deprecation:

1) /app/vendor/symfony/deprecation-contracts/function.php:25
some deprecations

Triggered by:

* Tests\SomeTest::testSomething duration
  /app/tests/SomeTest.php:xx

it would display:

1 tests triggered 1 deprecation:

1) /app/vendor/path/to/real/deprecation.php:xx
some deprecations

Triggered by:

* Tests\SomeTest::testSomething duration
  /app/tests/SomeTest.php:xx

[sebastianbergmann]

Makes sense, I guess. Do you want to send a PR for this?

[nikophil]

yes, let's do this :)