phpcbf crashes where there are 2 blank lines after the last use statement

[xalopp]

Type of issue

• Bug in MO4 sniffer rule.
• Bug in MO4 auto-fixer.
• Bug in MO4 documentation.
• Request to extend MO4 sniffer with specific rule.
• Request to extend MO4 auto-fixer for specific rule.
• Request to extend MO4 documentation.
• Other (explain):

Description

The file integrationtests/B.php contains following code

<?php

namespace T;

use A;


class B
{
  /**
   * B's constructor
   */
    public function __construct()
    {
        $a = new A();
        $a->b();
    }
}

The style violation consists of 2 blank lines between the last use statement and the class declaration.

$ vendor/bin/phpcs --standard=MO4 -s integrationtests/B.php

FILE: /home/x/mo4-coding-standard/integrationtests/B.php
-----------------------------------------------------------------------------------------------------------------------------------------------
FOUND 4 ERRORS AFFECTING 2 LINES
-----------------------------------------------------------------------------------------------------------------------------------------------
 5 | ERROR | [x] Expected 1 line after last use statement, found 2.
   |       |     (SlevomatCodingStandard.Namespaces.UseSpacing.IncorrectLinesCountAfterLastUse)
 5 | ERROR | [x] There must be one blank line after the last USE statement; 2 found;
   |       |     (MO4.Formatting.AlphabeticalUseStatements.SpaceAfterLastUse)
 5 | ERROR | [x] Header blocks must be separated by a single blank line (PSR12.Files.FileHeader.SpacingAfterBlock)
 6 | ERROR | [x] Multiple empty lines should not exist in a row; found 2 consecutive empty lines
   |       |     (MO4.WhiteSpace.MultipleEmptyLines.MultipleEmptyLines)
-----------------------------------------------------------------------------------------------------------------------------------------------
PHPCBF CAN FIX THE 4 MARKED SNIFF VIOLATIONS AUTOMATICALLY
-----------------------------------------------------------------------------------------------------------------------------------------------

Time: 39ms; Memory: 10MB

We see, that more than on sniff are complaining.

Using the autofixer fails, with an exception in a non relevant sniff MO4.Formatting.UnnecessaryNamespaceUsage

$ vendor/bin/phpcbf --standard=MO4 -s integrationtests/B.php
PHP Fatal error:  Uncaught PHP_CodeSniffer\Exceptions\RuntimeException: Uninitialized string offset 0 in /home/x/mo4-coding-standard/MO4/Sniffs/Formatting/UnnecessaryNamespaceUsageSniff.php on line 313 in /home/x/Projekte/PHP/mo4-coding-standard/vendor/squizlabs/php_codesniffer/src/Runner.php:624
Stack trace:
#0 /home/x/mo4-coding-standard/MO4/Sniffs/Formatting/UnnecessaryNamespaceUsageSniff.php(313): PHP_CodeSniffer\Runner->handleErrors()
#1 /home/x/mo4-coding-standard/MO4/Sniffs/Formatting/UnnecessaryNamespaceUsageSniff.php(258): MO4\Sniffs\Formatting\UnnecessaryNamespaceUsageSniff->getFullyQualifiedClassName()
#2 /home/x/mo4-coding-standard/MO4/Sniffs/Formatting/UnnecessaryNamespaceUsageSniff.php(92): MO4\Sniffs\Formatting\UnnecessaryNamespaceUsageSniff->getUseStatements()
#3 /home/x/mo4-coding-standard/vendor/squizlabs/php_codesniffer/src/Files/File.php(519): MO4\Sniffs\Formatting\UnnecessaryNamespaceUsageSniff->process()
#4 /home/x/mo4-coding-standard/vendor/squizlabs/php_codesniffer/src/Files/LocalFile.php(92): PHP_CodeSniffer\Files\File->process()
#5 /home/x/mo4-coding-standard/vendor/squizlabs/php_codesniffer/src/Fixer.php(175): PHP_CodeSniffer\Files\LocalFile->process()
#6 /home/x/mo4-coding-standard/vendor/squizlabs/php_codesniffer/src/Reports/Cbf.php(53): PHP_CodeSniffer\Fixer->fixFile()
#7 /home/x/mo4-coding-standard/vendor/squizlabs/php_codesniffer/src/Reporter.php(285): PHP_CodeSniffer\Reports\Cbf->generateFileReport()
#8 /home/x/mo4-coding-standard/vendor/squizlabs/php_codesniffer/src/Runner.php(714): PHP_CodeSniffer\Reporter->cacheFileReport()
#9 /home/x/mo4-coding-standard/vendor/squizlabs/php_codesniffer/src/Runner.php(454): PHP_CodeSniffer\Runner->processFile()
#10 /home/x/mo4-coding-standard/vendor/squizlabs/php_codesniffer/src/Runner.php(216): PHP_CodeSniffer\Runner->run()
#11 /home/x/mo4-coding-standard/vendor/squizlabs/php_codesniffer/bin/phpcbf(14): PHP_CodeSniffer\Runner->runPHPCBF()
#12 /home/x/mo4-coding-standard/vendor/bin/phpcbf(119): include('...')
#13 {main}
  thrown in /home/x/mo4-coding-standard/vendor/squizlabs/php_codesniffer/src/Runner.php on line 624

$ vendor/bin/phpcbf --standard=MO4 -s integrationtests/B.php --exclude=MO4.Formatting.UnnecessaryNamespaceUsage

works.

Technical details

• PHP version: PHP 8.3.6 (cli) (built: Sep 30 2024 15:17:17) (NTS)
• PHPCS version: squizlabs/php_codesniffer 3.11.2
• MO4 version: Relse 10.0.0 commit a7b983b
• OS: Ubuntu 24.04.1 LTS

[xalopp]

I was able to identify the root cause of the issue.

When the use and class are on the same line, then the sniff triggers an error:

<?php

namespace T;

use A;class B
{
  /**
   * B's constructor
   */
    public function __construct()
    {
        $a = new A();
        $a->b();
    }
}

$ vendor/bin/phpcs -s --standard=MO4 integrationtests/C.php

FILE: /home/x/Projekte/PHP/mo4-coding-standard/integrationtests/C.php
-----------------------------------------------------------------------------------------------------------------------------------------------
FOUND 4 ERRORS AFFECTING 2 LINES
-----------------------------------------------------------------------------------------------------------------------------------------------
 1 | ERROR | [ ] An error occurred during processing; checking has been aborted. The error message was: Uninitialized string offset 0 in
   |       |     /home/x/mo4-coding-standard/MO4/Sniffs/Formatting/UnnecessaryNamespaceUsageSniff.php on line 313
   |       |     The error originated in the MO4.Formatting.UnnecessaryNamespaceUsage sniff on line 313. (Internal.Exception)
 5 | ERROR | [x] Expected 1 line after last use statement, found -1.
   |       |     (SlevomatCodingStandard.Namespaces.UseSpacing.IncorrectLinesCountAfterLastUse)
 5 | ERROR | [x] There must be one blank line after the last USE statement; 0 found;
   |       |     (MO4.Formatting.AlphabeticalUseStatements.SpaceAfterLastUse)
 5 | ERROR | [x] Header blocks must be separated by a single blank line (PSR12.Files.FileHeader.SpacingAfterBlock)
-----------------------------------------------------------------------------------------------------------------------------------------------
PHPCBF CAN FIX THE 3 MARKED SNIFF VIOLATIONS AUTOMATICALLY
-----------------------------------------------------------------------------------------------------------------------------------------------

PR #213 will solve this