False positive: Throw_ mutant not covered by tests

[ghostwriter]

Question	Answer
Infection version	0.26.16
Test Framework version	PHPUnit 9.5.27
PHP version	8.1.13
Platform	MacOS & Ubuntu
Github Repo	ghostwriter/option ghostwriter/result

1. ghostwriter/option/src/Traits/OptionTrait.php:70 [M] Throw_

--- Original
+++ New
@@ @@
     public function expect(Throwable $throwable) : mixed
     {
         if ($this instanceof NoneInterface) {
-            throw $throwable;
+            $throwable;
         }
         return $this->value;
     }

This test explicitly checks that the method throws a specific exception with a specific exception message, but that doesn’t satisfy infection. ghostwriter/option/tests/Unit/NoneTest.php:102

I keep seeing multiple instances of this same error in many repositories.

I believe it is a false positive or bug because, in each instance, I have 100% test coverage.

eg. :
https://github.com/ghostwriter/option/actions/runs/3710778536/jobs/6290589145
https://github.com/ghostwriter/result/actions/runs/3710486045/jobs/6290051681

[sanmai]

Please try:

composer require --dev phpunit/php-code-coverage:^9.2.21

And report if you still have the issue.

[ghostwriter]

I still have the same issue.

[sanmai]

Here's what I did.

I generated a coverage report with php vendor/bin/phpunit --coverage-html=coverage and saw:

Then I downgraded the package to the earliest known working version as per #1773:

composer require --dev phpunit/php-code-coverage:=9.2.16

And saw:

[Slamdunk]

Yup, an easy fix is needed in phpunit/php-code-coverage indeed, hope to propose it today

[romm]

I can confirm with a similar issue, see https://dashboard.stryker-mutator.io/reports/github.com/CuyZ/Valinor/master#mutant/Type/Types/UnresolvableType.php

[Slamdunk]

Fix proposed in sebastianbergmann/php-code-coverage#969

[ghostwriter]

@sanmai Thanks for your help pinpointing the main issue and @Slamdunk Thanks for providing the solution.

[sanmai]

Shall we close this as completed?

[ghostwriter]

Personally, I’d wait until there’s a new tag released for sebastianbergmann/php-code-coverage, but ultimately the issue has been addressed so I’m okay with your decision.

[sanmai]

Thanks for raising this issue. I don't see we can do anything more here.

If there is more to the issue, please inspect the coverage report and open any issues with the packages where they appear. Thanks again.