Added DisallowIncrementAndDecrementOperatorsSniff

Author: kukulich

README.md

@@ -100,6 +100,10 @@ Requires use of null coalesce operator when possible.
 
 Requires use of early exit.
 
+#### SlevomatCodingStandard.Operators.DisallowIncrementAndDecrementOperators
+
+Disallows using `++` and `--` operators.
+
 ### Cleaning - detecting dead code
 
 #### SlevomatCodingStandard.Classes.UnusedPrivateElements 🚧

SlevomatCodingStandard/Sniffs/Operators/DisallowIncrementAndDecrementOperatorsSniff.php

@@ -0,0 +1,60 @@
+<?php declare(strict_types = 1);
+
+namespace SlevomatCodingStandard\Sniffs\Operators;
+
+use SlevomatCodingStandard\Helpers\TokenHelper;
+
+class DisallowIncrementAndDecrementOperatorsSniff implements \PHP_CodeSniffer\Sniffs\Sniff
+{
+
+	public const CODE_DISALLOWED_PRE_INCREMENT_OPERATOR = 'DisallowedPreIncrementOperator';
+	public const CODE_DISALLOWED_POST_INCREMENT_OPERATOR = 'DisallowedPostIncrementOperator';
+	public const CODE_DISALLOWED_PRE_DECREMENT_OPERATOR = 'DisallowedPreDecrementOperator';
+	public const CODE_DISALLOWED_POST_DECREMENT_OPERATOR = 'DisallowedPostDecrementOperator';
+
+	/**
+	 * @return mixed[]
+	 */
+	public function register(): array
+	{
+		return [
+			T_DEC,
+			T_INC,
+		];
+	}
+
+	/**
+	 * @phpcsSuppress SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingParameterTypeHint
+	 * @param \PHP_CodeSniffer\Files\File $phpcsFile
+	 * @param int $operatorPointer
+	 */
+	public function process(\PHP_CodeSniffer\Files\File $phpcsFile, $operatorPointer): void
+	{
+		$tokens = $phpcsFile->getTokens();
+
+		$previousPointer = TokenHelper::findPreviousEffective($phpcsFile, $operatorPointer - 1);
+
+		$isPostOperator = $tokens[$previousPointer]['code'] === T_VARIABLE;
+
+		if ($tokens[$operatorPointer]['code'] === T_INC) {
+			if ($isPostOperator) {
+				$code = self::CODE_DISALLOWED_POST_INCREMENT_OPERATOR;
+				$message = 'Use of post-increment operator is disallowed.';
+			} else {
+				$code = self::CODE_DISALLOWED_PRE_INCREMENT_OPERATOR;
+				$message = 'Use of pre-increment operator is disallowed.';
+			}
+		} else {
+			if ($isPostOperator) {
+				$code = self::CODE_DISALLOWED_POST_DECREMENT_OPERATOR;
+				$message = 'Use of post-decrement operator is disallowed.';
+			} else {
+				$code = self::CODE_DISALLOWED_PRE_DECREMENT_OPERATOR;
+				$message = 'Use of pre-decrement operator is disallowed.';
+			}
+		}
+
+		$phpcsFile->addError($message, $operatorPointer, $code);
+	}
+
+}

tests/Sniffs/Operators/DisallowIncrementAndDecrementOperatorsSniffTest.php

@@ -0,0 +1,25 @@
+<?php declare(strict_types = 1);
+
+namespace SlevomatCodingStandard\Sniffs\Operators;
+
+class DisallowIncrementAndDecrementOperatorsSniffTest extends \SlevomatCodingStandard\Sniffs\TestCase
+{
+
+	public function testNoErrors(): void
+	{
+		self::assertNoSniffErrorInFile(self::checkFile(__DIR__ . '/data/disallowIncrementAndDecrementOperatorsNoErrors.php'));
+	}
+
+	public function testErrors(): void
+	{
+		$report = self::checkFile(__DIR__ . '/data/disallowIncrementAndDecrementOperatorsErrors.php');
+
+		self::assertSame(4, $report->getErrorCount());
+
+		self::assertSniffError($report, 3, DisallowIncrementAndDecrementOperatorsSniff::CODE_DISALLOWED_POST_INCREMENT_OPERATOR);
+		self::assertSniffError($report, 4, DisallowIncrementAndDecrementOperatorsSniff::CODE_DISALLOWED_PRE_INCREMENT_OPERATOR);
+		self::assertSniffError($report, 6, DisallowIncrementAndDecrementOperatorsSniff::CODE_DISALLOWED_POST_DECREMENT_OPERATOR);
+		self::assertSniffError($report, 7, DisallowIncrementAndDecrementOperatorsSniff::CODE_DISALLOWED_PRE_DECREMENT_OPERATOR);
+	}
+
+}

tests/Sniffs/Operators/data/disallowIncrementAndDecrementOperatorsErrors.php

@@ -0,0 +1,7 @@
+<?php
+
+$i++;
+++$j;
+
+$k--;
+--$l;

tests/Sniffs/Operators/data/disallowIncrementAndDecrementOperatorsNoErrors.php

@@ -0,0 +1,5 @@
+<?php
+
+$i+= 1;
+
+$j-= 1;