Alternative syntax for control structures triggers false "multi-line if statement" error

[sun]

Problem

• The alternative syntax for control structures triggers a false "multi-line IF statement" error when the colon is placed directly after the statement.

Goal

• Make correct code pass coding style tests.

Details

• PSR-2 does not define rules for the alternative syntax for control structures. But its lack of rules for the alternative syntax should not affect the CodeSniffer's general ability to apply sensible, readable coding standards. Especially given the fact that PHPCS supports the alternate syntax already.

• This issue affects many software projects using a PHP based templating system; for instance, WordPress, Drupal (7 and below), and others. Most of them predate PSR-2. You may not like these systems personally, but they do have their place and people are trying to use PHPCS to ensure consistent coding standards. Fixing the issue helps to increase adoption of modern tool chains.

• This topic was brought up in similar or incomplete ways in a few issues in the past already, the closest ones were Issue checking alternative control structures syntax #935 (alternate syntax) and phpcbf with PSR2 errors on control structure alternative syntax #366 (legacy templates).

Test case

<?php

/**
 * @file
 * Test alternative syntax for control structures.
 */
?>

<?php foreach ([1, 2] as $number): ?>
    <?php echo $number ?> is a number.
<?php endforeach; ?>

<?php if ($number): ?>
    <?php echo $number ?> is a good number.
<?php else: ?>
    <?php echo $number ?> is a bad number.
<?php endif; ?>

<?php switch ($number): ?>
<?php case 1: ?>
    <?php echo $number ?> is a low number.
    <?php break; ?>

  <?php default: ?>
    <?php echo $number ?> is another number.
<?php endswitch; ?>

<?php while (--$number): ?>
    <?php echo $number ?> is a lower number.
<?php endwhile; ?>

Setup

$ composer global require "squizlabs/php_codesniffer=*"
$ composer global require 'drupal/coder:>8'
$ composer global require dealerdirect/phpcodesniffer-composer-installer
$ phpcs --version
PHP_CodeSniffer version 3.4.2 (stable) by Squiz (http://www.squiz.net)

Result

❌ Expected 1 space after closing parenthesis; found 0
❌ Expected 1 space after ELSE keyword; 0 found

$ phpcs --standard=Drupal -v alternative-syntax.php 
Registering sniffs in the Drupal standard... DONE (114 sniffs registered)
Creating file list... DONE (1 files in queue)
Changing into directory ./phpcs
Processing alternative-syntax.php [PHP => 161 tokens in 30 lines]... DONE in 9ms (9 errors, 2 warnings)

FILE: ./phpcs/alternative-syntax.php
---------------------------------------------------------------------------------------------
FOUND 9 ERRORS AND 2 WARNINGS AFFECTING 10 LINES
---------------------------------------------------------------------------------------------
  9 | ERROR   | [x] Expected 1 space after closing parenthesis; found 0
 13 | ERROR   | [x] Expected 1 space after closing parenthesis; found 0
 15 | ERROR   | [x] Expected 1 space after ELSE keyword; 0 found
 19 | ERROR   | [x] Expected 1 space after closing parenthesis; found 0
 20 | ERROR   | [x] Line indented incorrectly; expected 2 spaces, found 0
 22 | ERROR   | [x] Case breaking statements must be followed by a single blank line
 22 | ERROR   | [x] Case breaking statement indented incorrectly; expected 2 spaces, found 4
 23 | WARNING | [ ] Code after the BREAK statement on line 22 cannot be executed
 24 | WARNING | [ ] Code after the BREAK statement on line 22 cannot be executed
 28 | ERROR   | [x] Expected 1 space after closing parenthesis; found 0
 30 | ERROR   | [x] A closing tag is not permitted at the end of a PHP file
---------------------------------------------------------------------------------------------
PHPCBF CAN FIX THE 9 MARKED SNIFF VIOLATIONS AUTOMATICALLY
---------------------------------------------------------------------------------------------

Time: 78ms; Memory: 6MB

[gsherwood]

My comment from one of the linked issues is still my position: #935 (comment)

Summary: I'm not going to write custom sniffs for PSR-2 just to ignore alternative control structures because it is too much work. PSR-2 says that all control structures must use braces, but I'm not going to look for and ban alternate syntax, even though that is actually pretty easy to do.

I don't use template files, but developers who do have recommended that they not be checked with the same coding standard you use for class files, and many recommend ignoring them completely.

As PSR-2 does not define how alternate control structures should be written, I'd recommend excluding the sniffs or codes that you don't want only on template files.

These two examples from the annotated ruleset show how to exclude an entire sniff, or just a single error code, from some files in your project:

 <!--
    You can hard-code ignore patterns for specific sniffs,
    a feature not available on the command line. Please note that
    all sniff-specific ignore patterns are checked using absolute paths.

    The code here will hide all messages from the Squiz DoubleQuoteUsage
    sniff for files that match either of the two exclude patterns.
 -->
 <rule ref="Squiz.Strings.DoubleQuoteUsage">
    <exclude-pattern>*/tests/*</exclude-pattern>
    <exclude-pattern>*/data/*</exclude-pattern>
 </rule>

 <!--
    You can also be more specific and just exclude some messages.
    Please note that all message-specific ignore patterns are
    checked using absolute paths.

    The code here will just hide the ContainsVar error generated by the
    Squiz DoubleQuoteUsage sniff for files that match either of the two
    exclude patterns.
 -->
 <rule ref="Squiz.Strings.DoubleQuoteUsage.ContainsVar">
    <exclude-pattern>*/tests/*</exclude-pattern>
    <exclude-pattern>*/data/*</exclude-pattern>
 </rule>

Does any of that help?

[gsherwood]

Closing due to lack of feedback. Hopefully the exclude rules help.