ControlStructures/AssignmentInCondition: prevent fatal error during live coding

[jrfnl]

Fixes:

Fatal error: Uncaught TypeError: SlevomatCodingStandard\Sniffs\ControlStructures\AssignmentInConditionSniff::processCondition(): Argument #3 ($parenthesisCloser) must be of type int, null given, called in path\to\SlevomatCodingStandard\Sniffs\ControlStructures\AssignmentInConditionSniff.php on line 56 and defined in path\to\SlevomatCodingStandard\Sniffs\ControlStructures\AssignmentInConditionSniff.php:59
Stack trace:
#0 path\to\SlevomatCodingStandard\Sniffs\ControlStructures\AssignmentInConditionSniff.php(56): SlevomatCodingStandard\Sniffs\ControlStructures\AssignmentInConditionSniff->processCondition(Object(PHP_CodeSniffer\Files\LocalFile), 100, NULL, 'if')
#1 D:\000_GitHub\PHPCS\PHP_CodeSniffer\src\Files\File.php(509): SlevomatCodingStandard\Sniffs\ControlStructures\AssignmentInConditionSniff->process(Object(PHP_CodeSniffer\Files\LocalFile), 99)
#2 D:\000_GitHub\PHPCS\PHP_CodeSniffer\src\Files\LocalFile.php(92): PHP_CodeSniffer\Files\File->process()
#3 D:\000_GitHub\PHPCS\PHP_CodeSniffer\src\Runner.php(632): PHP_CodeSniffer\Files\LocalFile->process()
#4 D:\000_GitHub\PHPCS\PHP_CodeSniffer\src\Runner.php(438): PHP_CodeSniffer\Runner->processFile(Object(PHP_CodeSniffer\Files\LocalFile))
#5 D:\000_GitHub\PHPCS\PHP_CodeSniffer\src\Runner.php(116): PHP_CodeSniffer\Runner->run()
#6 D:\000_GitHub\PHPCS\PHP_CodeSniffer\bin\phpcs(18): PHP_CodeSniffer\Runner->runPHPCS()
#7 {main}
  thrown in path\to\SlevomatCodingStandard\Sniffs\ControlStructures\AssignmentInConditionSniff.php on line 59

[jrfnl]

The build failure, IMO, is incorrect.

Linting and the coding standards are being run over the test fixtures, while those should be able to contain horribly bad code and parse errors just to ensure that the actual sniff handles this correctly.

In my opinion, the test fixtures should be excluded from linting and the PHPCS check, though I'm open to hearing other suggestions on how to get round this.

[jrfnl]

Oh and the PHPStan error is also incorrect. Not sure where it is basing the information off, but those keys can easily not be set. Adding treatPhpDocTypesAsCertain: false to the configuration might fix this ?