I've looked into 10067 and have come to the conclusion that using a single regex to strip the heredoc/nowdocs is always going to run into trouble as:
* Either the matching will be too greedy (issue 10067);
* Or the matching will run into backtrace limits for large heredoc/nowdocs.
We cannot solve both within a single regex.
So, I'm proposing a slightly different solution which should support both and should also improve performance for files containing large heredoc/nowdocs.
The `stripHereNowDocs()` function will find a start marker and remember the offset of the start marker.
It will then find the end marker and strip the contents between the two (replace with `null`).
The function will then recurse onto itself until all heredocs/nowdocs in a file have been removed.
By using a look ahead assertion to match "new line - maybe whitespace - marker", the negative performance impact of the `.*` is significantly mitigated and backtracing will be severely limited.
This fixes the bug as reported in 10037.
The bug was discovered due to a PHP 8.1 "passing null to non-nullable" deprecation notice being thrown, but is not a PHP 8.1 bug.
In actual fact, this issue affected all PHP versions and could lead to incomplete classmaps when the code base contained files with huge heredocs/nowdocs.
The regex change (not completely) incidentally also fixes an issue with markers in a heredoc/nowdoc not being correctly handled. This bug could lead to "classes" being added to the class map which aren't actually classes.
Fixes 10037
PHP 8.1 supports Enums, and [Enums follow class-semantics](https://php.watch/versions/8.1/enums#class-semantics-autoload).
Composer's class-map generator currently looks for `class`, `interface`, and `trait` keywords. If Composer is run in PHP 8.1 or later, Composer now additionally looks for `enum` keyword as well. This is similar to how Hack's `enum` support is added.
This PR also adds tests for basic enums, backed enums, namespaced enums, and an enum that implements an interface and extends a class.
Jordi Boggiano
Niels Vanpachtenbeke
immeëmosol
jrfnl
Ayesh Karunaratne
Simon Berger
Graham Campbell
Markus Staab
Andriy Maletsky
zakonnic
Rob Bast