Summary

Hi 👋

When deprecations are encountered the SouceMapper recursively scans all files for each <source> include and exclude paths.

This causes a siginficant pause in PHPUnit as it scans all these files, initially for 16 seconds until we isolated the issue and refined the <source> list - now it's "only" 3 seconds.

Current behavior

Scans all files when a deprecation is encountered.

How to reproduce

Add a <source> configuration:

    <source>
        <include>
            <directory suffix=".php">src/</directory>
            <directory suffix=".php">perhaps-another-directory-here/</directory>
        </include>
        <exclude>
            <directory suffix=".php">src/SubFolder</directory>
            <!-- maybe serveral more here -->
        </exclude>
    </source>

• Run a test that would trigger a deprecation
• Observe that source mapper will recursively iterate over all the files in the above paths.

https://github.com/sebastianbergmann/phpunit/blob/main/src/Runner/ErrorHandler.php#L178

Expected behavior

That a triggered deprecation would not scan all the files and block the test run for N seconds.