Use relative directories for packages when building GeneratedConfig

[cjunge-work]

Build the GeneratedConfig file using relative paths so PHPStan can be run inside/outside containers/CI, etc.

Fixes #17

[cjunge-work]

@ondrejmirtes any chance this could be merged?

[arnaudgoulpeau]

Hi, we work with Docker and the composer image. We have the same problem and any though on this PR would be greatly appreciated. Even if it is a big no.
By the way, thanks for all the great stuff here !

[ondrejmirtes]

Hi,
I'm not sure about the implications of this, it would need a lot of testing. We'd first need an extensive test suite that would allow us testing this on Linux/Windows using GitHub Actions making sure we didn't break anything.

[ondrejmirtes]

When looking at the implementation, I already know that this is wrong:

		$vendorPos = strpos(__DIR__, 'vendor');
		if ($vendorPos === false) {
			return;
		}

Composer users can change their vendor-dir using configuration: https://getcomposer.org/doc/06-config.md#vendor-dir

[ondrejmirtes]

I stand by my comment from #17:

I'm fine if this utility isn't usable by everyone. It can afford to only solve the happy path for its users. The only thing it does is to save typing a few lines in your phpstan.neon.

[stof]

Actually, we can know that the vendor folder is always dirname(__DIR__, 3) here, as this file is in <vendor-dir>/phpstan/extension-installer/src whatever the vendor-dir is named.

[stof]

An alternative solution could be to rely on Composer\Util\Filesystem::findShortestPathCode instead (but it might require changing the way $data is handled for the file generation then as var_export($data, true) won't do it anymore)

[ondrejmirtes]

I plan to tackle this myself, thank you.

[ondrejmirtes]

This was all that was needed: 66c7adc + phpstan/phpstan-src@0e306c6