UselessVariableSniff: Fixed false positives

Author: kukulich

SlevomatCodingStandard/Sniffs/Variables/UselessVariableSniff.php

@@ -9,6 +9,7 @@
 use const T_CLOSE_CURLY_BRACKET;
 use const T_CONCAT_EQUAL;
 use const T_DIV_EQUAL;
+use const T_DOC_COMMENT_CLOSE_TAG;
 use const T_EQUAL;
 use const T_MINUS_EQUAL;
 use const T_MOD_EQUAL;
@@ -20,12 +21,16 @@
 use const T_SEMICOLON;
 use const T_SL_EQUAL;
 use const T_SR_EQUAL;
+use const T_STATIC;
 use const T_VARIABLE;
+use const T_WHITESPACE;
 use const T_XOR_EQUAL;
 use function array_key_exists;
 use function array_reverse;
 use function count;
 use function in_array;
+use function preg_match;
+use function preg_quote;
 use function sprintf;
 
 class UselessVariableSniff implements Sniff
@@ -94,6 +99,21 @@ public function process(File $phpcsFile, $returnPointer): void
 			return;
 		}
 
+		$effectivePointerBeforePreviousVariable = TokenHelper::findPreviousEffective($phpcsFile, $previousVariablePointer - 1);
+		if ($tokens[$effectivePointerBeforePreviousVariable]['code'] === T_STATIC) {
+			return;
+		}
+
+		$pointerBeforePreviousVariable = TokenHelper::findPreviousExcluding($phpcsFile, T_WHITESPACE, $previousVariablePointer - 1);
+		if (
+			$tokens[$pointerBeforePreviousVariable]['code'] === T_DOC_COMMENT_CLOSE_TAG
+		) {
+			$docCommentContent = TokenHelper::getContent($phpcsFile, $tokens[$pointerBeforePreviousVariable]['comment_opener'], $pointerBeforePreviousVariable);
+			if (preg_match('~@var\\s+\\S+\\s+' . preg_quote($variableName, '~') . '~', $docCommentContent)) {
+				return;
+			}
+		}
+
 		/** @var int $assigmentPointer */
 		$assigmentPointer = TokenHelper::findNextEffective($phpcsFile, $previousVariablePointer + 1);
 		if (!in_array($tokens[$assigmentPointer]['code'], [

tests/Sniffs/Variables/data/uselessVariableNoErrors.php

@@ -36,3 +36,14 @@ function differentVariable() {
 	$e = 10;
 	return $f;
 }
+
+function staticVariable() {
+	static $g = null;
+	return $g;
+}
+
+function withDocComment() {
+	/** @var string $h */
+	$h = 'h';
+	return $h;
+}