Add MultipleEmptyLinesSniff

Author: mmoll

CHANGELOG.md

@@ -5,7 +5,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ## [8.0.0] -
 ### Added
-- Add MO4.WhiteSpace.ConstantSpacing
+- Add `MO4.WhiteSpace.ConstantSpacing`
+- Add `MO4.WhiteSpace.MultipleEmptyLinesSniff`
 ### Changed
 - refactored tests
 

MO4/Sniffs/WhiteSpace/MultipleEmptyLinesSniff.php

@@ -0,0 +1,97 @@
+<?php
+
+/**
+ *
+ * Check multiple consecutive newlines in a file.
+ * Source: MediaWiki. I didn't want to add dependency to whole package (because of only one sniff).
+ *
+ * @link https://github.com/wikimedia/mediawiki-tools-codesniffer/blob/272835d/MediaWiki/Sniffs/WhiteSpace/MultipleEmptyLinesSniff.php
+ */
+
+namespace MO4\Sniffs\WhiteSpace;
+
+use PHP_CodeSniffer\Files\File;
+use PHP_CodeSniffer\Sniffs\Sniff;
+
+class MultipleEmptyLinesSniff implements Sniff
+{
+    /**
+     * Registers the tokens that this sniff wants to listen for.
+     *
+     * @return array<int, int>
+     *
+     * @see Tokens.php
+     */
+    public function register(): array
+    {
+        return [
+            // Assume most comments end with a newline
+            T_COMMENT,
+            // Assume all <?php open tags end with a newline
+            T_OPEN_TAG,
+            T_WHITESPACE,
+        ];
+    }
+
+    /**
+     * @phpcsSuppress SlevomatCodingStandard.TypeHints.ParameterTypeHint
+     *
+     * @param File $phpcsFile
+     * @param int  $stackPtr  The current token index.
+     *
+     * @return void|int
+     */
+    public function process(File $phpcsFile, $stackPtr)
+    {
+        $tokens = $phpcsFile->getTokens();
+
+        // This sniff intentionally doesn't care about whitespace at the end of the file
+        if (!isset($tokens[$stackPtr + 3])
+            || $tokens[$stackPtr + 2]['line'] === $tokens[$stackPtr + 3]['line']
+        ) {
+            return $stackPtr + 3;
+        }
+
+        if ($tokens[$stackPtr + 1]['line'] === $tokens[$stackPtr + 2]['line']) {
+            return $stackPtr + 2;
+        }
+
+        // Finally, check the assumption the current token is or ends with a newline
+        if ($tokens[$stackPtr]['line'] === $tokens[$stackPtr + 1]['line']) {
+            return;
+        }
+
+        // Search for the next non-newline token
+        $next = $stackPtr + 1;
+
+        while (isset($tokens[$next + 1]) &&
+            $tokens[$next]['code'] === T_WHITESPACE &&
+            $tokens[$next]['line'] !== $tokens[$next + 1]['line']
+        ) {
+            $next++;
+        }
+
+        $count = $next - $stackPtr - 1;
+
+        if ($count > 1
+            && $phpcsFile->addFixableError(
+                'Multiple empty lines should not exist in a row; found %s consecutive empty lines',
+                $stackPtr + 1,
+                'MultipleEmptyLines',
+                [$count]
+            )
+        ) {
+            $phpcsFile->fixer->beginChangeset();
+
+            // Remove all newlines except the first two, i.e. keep one empty line
+            for ($i = $stackPtr + 2; $i < $next; $i++) {
+                $phpcsFile->fixer->replaceToken($i, '');
+            }
+
+            $phpcsFile->fixer->endChangeset();
+        }
+
+        // Don't check the current sequence a second time
+        return $next;
+    }
+}

MO4/Tests/WhiteSpace/MultipleEmptyLinesUnitTest.fail.inc

@@ -0,0 +1,48 @@
+<?php
+
+
+/**
+ * license header etc.
+ */
+
+/**
+ * Failed examples.
+ * @return void
+ */
+function wfFailedExamples() {
+	$a = 1;
+
+
+
+
+
+
+	$b = 2;
+	
+	
+	// Comment
+
+
+
+
+	// Comment 2
+
+
+	// Comment 3
+
+	/* Comment 4 */
+
+	# Comment 5
+
+	$c = 3;
+}
+
+/**
+ * Passed examples.
+ * @return void
+ */
+function wfPassedExamples() {
+	$a = 1;
+
+	$b = 2;
+}

MO4/Tests/WhiteSpace/MultipleEmptyLinesUnitTest.fail.inc.fixed

@@ -0,0 +1,37 @@
+<?php
+
+/**
+ * license header etc.
+ */
+
+/**
+ * Failed examples.
+ * @return void
+ */
+function wfFailedExamples() {
+	$a = 1;
+
+	$b = 2;
+	
+	// Comment
+
+	// Comment 2
+
+	// Comment 3
+
+	/* Comment 4 */
+
+	# Comment 5
+
+	$c = 3;
+}
+
+/**
+ * Passed examples.
+ * @return void
+ */
+function wfPassedExamples() {
+	$a = 1;
+
+	$b = 2;
+}

MO4/Tests/WhiteSpace/MultipleEmptyLinesUnitTest.pass.inc

@@ -0,0 +1,37 @@
+<?php
+
+/**
+ * license header etc.
+ */
+
+/**
+ * Failed examples.
+ * @return void
+ */
+function wfFailedExamples() {
+	$a = 1;
+
+	$b = 2;
+
+	// Comment
+
+	// Comment 2
+
+	// Comment 3
+
+	/* Comment 4 */
+
+	# Comment 5
+
+	$c = 3;
+}
+
+/**
+ * Passed examples.
+ * @return void
+ */
+function wfPassedExamples() {
+	$a = 1;
+
+	$b = 2;
+}

MO4/Tests/WhiteSpace/MultipleEmptyLinesUnitTest.php

@@ -0,0 +1,45 @@
+<?php
+
+/**
+ * This file is part of the mo4-coding-standard (phpcs standard)
+ *
+ * @author  Xaver Loppenstedt <[email protected]>
+ *
+ * @license http://spdx.org/licenses/MIT MIT License
+ *
+ * @link    https://github.com/mayflower/mo4-coding-standard
+ */
+
+declare(strict_types=1);
+
+namespace MO4\Tests\WhiteSpace;
+
+use MO4\Tests\AbstractMo4SniffUnitTest;
+
+/**
+ * Unit test class for the MultipleEmptyLines sniff.
+ *
+ * A sniff unit test checks a .inc file for expected violations of a single
+ * coding standard. Expected errors and warnings are stored in this class.
+ *
+ * @author    Xaver Loppenstedt <[email protected]>
+ *
+ * @copyright 2013 Xaver Loppenstedt, some rights reserved.
+ *
+ * @license   http://spdx.org/licenses/MIT MIT License
+ *
+ * @link      https://github.com/mayflower/mo4-coding-standard
+ */
+class MultipleEmptyLinesUnitTest extends AbstractMo4SniffUnitTest
+{
+    protected $expectedErrorList = [
+        'MultipleEmptyLinesUnitTest.pass.inc' => [],
+        'MultipleEmptyLinesUnitTest.fail.inc' => [
+            2  => 1,
+            14 => 1,
+            21 => 1,
+            24 => 1,
+            29 => 1,
+        ],
+    ];
+}

README.md

@@ -77,10 +77,12 @@ To change the sorting order for your project, add this snippet to your custom `r
 ### MO4.Strings.VariableInDoubleQuotedString
 * Interpolated variables in double quoted strings must be surrounded by `{ }`, e.g. `{$VAR}` instead of `$VAR`.
 
-## MO4.WhiteSpace.ConstantSpacing
-
+### MO4.WhiteSpace.ConstantSpacing
 * const must be followed by a single space.
 
+### MO4.WhiteSpace.MultipleEmptyLines
+* No more than one empty consecutive line is allowed. Taken from [mediawiki/mediawiki-codesniffer](https://github.com/wikimedia/mediawiki-tools-codesniffer).
+
 ### Further rules (imported from other standards)
 * See `MO4/ruleset.xml`, which has each imported rule commented.