Simplify by replacing chained $var === const with in_array()

build/PHPStan/Build/OrChainIdenticalComparisonToInArrayRule.php

@@ -0,0 +1,163 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Build;
+
+use PhpParser\Node;
+use PhpParser\Node\Arg;
+use PhpParser\Node\ArrayItem;
+use PhpParser\Node\Expr;
+use PhpParser\Node\Expr\Array_;
+use PhpParser\Node\Expr\BinaryOp\BooleanOr;
+use PhpParser\Node\Expr\BinaryOp\Identical;
+use PhpParser\Node\Expr\ClassConstFetch;
+use PhpParser\Node\Expr\ConstFetch;
+use PhpParser\Node\Expr\FuncCall;
+use PhpParser\Node\Name;
+use PhpParser\Node\Scalar;
+use PhpParser\Node\Stmt\If_;
+use PHPStan\Analyser\Scope;
+use PHPStan\DependencyInjection\AutowiredParameter;
+use PHPStan\File\FileHelper;
+use PHPStan\Node\Printer\ExprPrinter;
+use PHPStan\Rules\IdentifierRuleError;
+use PHPStan\Rules\Rule;
+use PHPStan\Rules\RuleErrorBuilder;
+use function array_map;
+use function array_merge;
+use function array_shift;
+use function count;
+use function dirname;
+use function str_starts_with;
+
+/**
+ * @implements Rule<If_>
+ */
+final class OrChainIdenticalComparisonToInArrayRule implements Rule
+{
+
+	public function __construct(
+		#[AutowiredParameter]
+		private ExprPrinter $printer,
+		private FileHelper $fileHelper,
+		private bool $skipTests = true,
+	)
+	{
+	}
+
+	public function getNodeType(): string
+	{
+		return If_::class;
+	}
+
+	public function processNode(Node $node, Scope $scope): array
+	{
+		$errors = $this->processConditionNode($node->cond, $scope);
+		foreach ($node->elseifs as $elseifCondNode) {
+			$errors = array_merge($errors, $this->processConditionNode($elseifCondNode->cond, $scope));
+		}
+
+		return $errors;
+	}
+
+	/**
+	 * @return list<IdentifierRuleError>
+	 */
+	public function processConditionNode(Expr $condNode, Scope $scope): array
+	{
+		$comparisons = $this->unpackOrChain($condNode);
+		if (count($comparisons) < 2) {
+			return [];
+		}
+
+		$firstComparison = array_shift($comparisons);
+		if (!$firstComparison instanceof Identical) {
+			return [];
+		}
+
+		$subjectAndValue = $this->getSubjectAndValue($firstComparison);
+		if ($subjectAndValue === null) {
+			return [];
+		}
+
+		if ($this->skipTests && str_starts_with($this->fileHelper->normalizePath($scope->getFile()), $this->fileHelper->normalizePath(dirname(__DIR__, 3) . '/tests'))) {
+			return [];
+		}
+
+		$subjectNode = $subjectAndValue['subject'];
+		$subjectStr = $this->printer->printExpr($subjectNode);
+		$values = [$subjectAndValue['value']];
+
+		foreach ($comparisons as $comparison) {
+			if (!$comparison instanceof Identical) {
+				return [];
+			}
+
+			$currentSubjectAndValue = $this->getSubjectAndValue($comparison);
+			if ($currentSubjectAndValue === null) {
+				return [];
+			}
+
+			if ($this->printer->printExpr($currentSubjectAndValue['subject']) !== $subjectStr) {
+				return [];
+			}
+
+			$values[] = $currentSubjectAndValue['value'];
+		}
+
+		$errorBuilder = RuleErrorBuilder::message('This chain of identical comparisons can be simplified using in_array().')
+			->line($condNode->getStartLine())
+			->fixNode($condNode, static fn (Expr $node) => self::createInArrayCall($subjectNode, $values))
+			->identifier('or.chainIdenticalComparison');
+
+		return [$errorBuilder->build()];
+	}
+
+	/**
+	 * @return list<Expr>
+	 */
+	private function unpackOrChain(Expr $node): array
+	{
+		if ($node instanceof BooleanOr) {
+			return [...$this->unpackOrChain($node->left), ...$this->unpackOrChain($node->right)];
+		}
+
+		return [$node];
+	}
+
+	/**
+	 * @phpstan-assert-if-true Scalar|ClassConstFetch|ConstFetch $node
+	 */
+	private static function isSubjectNode(Expr $node): bool
+	{
+		return $node instanceof Scalar || $node instanceof ClassConstFetch || $node instanceof ConstFetch;
+	}
+
+	/**
+	 * @return array{subject: Expr, value: Scalar|ClassConstFetch|ConstFetch}|null
+	 */
+	private function getSubjectAndValue(Identical $comparison): ?array
+	{
+		if (self::isSubjectNode($comparison->left) && !self::isSubjectNode($comparison->left)) {
+			return ['subject' => $comparison->right, 'value' => $comparison->left];
+		}
+
+		if (!self::isSubjectNode($comparison->left) && self::isSubjectNode($comparison->right)) {
+			return ['subject' => $comparison->left, 'value' => $comparison->right];
+		}
+
+		return null;
+	}
+
+	/**
+	 * @param list<Scalar|ClassConstFetch|ConstFetch> $values
+	 */
+	private static function createInArrayCall(Expr $subjectNode, array $values): FuncCall
+	{
+		return new FuncCall(new Name('\in_array'), [
+			new Arg($subjectNode),
+			new Arg(new Array_(array_map(static fn ($value) => new ArrayItem($value), $values))),
+			new Arg(new ConstFetch(new Name('true'))),
+		]);
+	}
+
+}

build/phpstan.neon

@@ -131,6 +131,7 @@ rules:
 	- PHPStan\Build\OverrideAttributeThirdPartyMethodRule
 	- PHPStan\Build\SkipTestsWithRequiresPhpAttributeRule
 	- PHPStan\Build\MemoizationPropertyRule
+	- PHPStan\Build\OrChainIdenticalComparisonToInArrayRule
 
 services:
 	-

src/Fixable/PhpPrinterIndentationDetectorVisitor.php

@@ -8,6 +8,7 @@
 use PhpParser\NodeVisitor;
 use PhpParser\NodeVisitorAbstract;
 use function count;
+use function in_array;
 use function is_array;
 use function preg_match;
 use function preg_match_all;
@@ -47,7 +48,7 @@ public function enterNode(Node $node): ?int
 		$text = $this->origTokens->getTokenCode($node->getStartTokenPos(), $firstStmt->getStartTokenPos(), 0);
 
 		$c = preg_match_all('~\n([\\x09\\x20]*)~', $text, $matches, PREG_SET_ORDER);
-		if ($c === 0 || $c === false) {
+		if (in_array($c, [0, false], true)) {
 			return null;
 		}
 

src/Reflection/InitializerExprTypeResolver.php

@@ -864,7 +864,7 @@ public function getDivType(Expr $left, Expr $right, callable $getTypeCallback):
 
 		$rightScalarValues = $rightType->toNumber()->getConstantScalarValues();
 		foreach ($rightScalarValues as $scalarValue) {
-			if ($scalarValue === 0 || $scalarValue === 0.0) {
+			if (in_array($scalarValue, [0, 0.0], true)) {
 				return new ErrorType();
 			}
 		}
@@ -938,7 +938,7 @@ public function getModType(Expr $left, Expr $right, callable $getTypeCallback):
 		$rightScalarValues = $rightType->toNumber()->getConstantScalarValues();
 		foreach ($rightScalarValues as $scalarValue) {
 
-			if ($scalarValue === 0 || $scalarValue === 0.0) {
+			if (in_array($scalarValue, [0, 0.0], true)) {
 				return new ErrorType();
 			}
 		}

src/Rules/Keywords/ContinueBreakInLoopRule.php

@@ -10,6 +10,7 @@
 use PHPStan\Rules\Rule;
 use PHPStan\Rules\RuleErrorBuilder;
 use function array_reverse;
+use function in_array;
 use function sprintf;
 
 /**
@@ -52,13 +53,13 @@ public function processNode(Node $node, Scope $scope): array
 						->build(),
 				];
 			}
-			if (
-				$parentStmtType === Stmt\For_::class
-				|| $parentStmtType === Stmt\Foreach_::class
-				|| $parentStmtType === Stmt\Do_::class
-				|| $parentStmtType === Stmt\While_::class
-				|| $parentStmtType === Stmt\Switch_::class
-			) {
+			if (in_array($parentStmtType, [
+				Stmt\For_::class,
+				Stmt\Foreach_::class,
+				Stmt\Do_::class,
+				Stmt\While_::class,
+				Stmt\Switch_::class,
+			], true)) {
 				$value--;
 			}
 			if ($value === 0) {

src/Rules/UnusedFunctionParametersCheck.php

@@ -12,6 +12,7 @@
 use function array_combine;
 use function array_map;
 use function array_merge;
+use function in_array;
 use function is_array;
 use function is_string;
 use function sprintf;
@@ -78,7 +79,7 @@ private function getUsedVariables(Scope $scope, $node): array
 		if ($node instanceof Node) {
 			if ($node instanceof Node\Expr\FuncCall && $node->name instanceof Node\Name) {
 				$functionName = $this->reflectionProvider->resolveFunctionName($node->name, $scope);
-				if ($functionName === 'func_get_args' || $functionName === 'get_defined_vars') {
+				if (in_array($functionName, ['func_get_args', 'get_defined_vars'], true)) {
 					return $scope->getDefinedVariables();
 				}
 			}

src/Type/Php/DsMapDynamicMethodThrowTypeExtension.php

@@ -10,6 +10,7 @@
 use PHPStan\Type\Type;
 use PHPStan\Type\VoidType;
 use function count;
+use function in_array;
 
 #[AutowiredService]
 final class DsMapDynamicMethodThrowTypeExtension implements DynamicMethodThrowTypeExtension
@@ -18,7 +19,7 @@ final class DsMapDynamicMethodThrowTypeExtension implements DynamicMethodThrowTy
 	public function isMethodSupported(MethodReflection $methodReflection): bool
 	{
 		return $methodReflection->getDeclaringClass()->getName() === 'Ds\Map'
-			&& ($methodReflection->getName() === 'get' || $methodReflection->getName() === 'remove');
+			&& in_array($methodReflection->getName(), ['get', 'remove'], true);
 	}
 
 	public function getThrowTypeFromMethodCall(MethodReflection $methodReflection, MethodCall $methodCall, Scope $scope): ?Type

src/Type/Php/StrWordCountFunctionDynamicReturnTypeExtension.php

@@ -16,6 +16,7 @@
 use PHPStan\Type\Type;
 use PHPStan\Type\UnionType;
 use function count;
+use function in_array;
 
 #[AutowiredService]
 final class StrWordCountFunctionDynamicReturnTypeExtension implements DynamicFunctionReturnTypeExtension
@@ -35,14 +36,14 @@ public function getTypeFromFunctionCall(
 		$argsCount = count($functionCall->getArgs());
 		if ($argsCount === 1) {
 			return new IntegerType();
-		} elseif ($argsCount === 2 || $argsCount === 3) {
+		} elseif (in_array($argsCount, [2, 3], true)) {
 			$formatType = $scope->getType($functionCall->getArgs()[1]->value);
 			if ($formatType instanceof ConstantIntegerType) {
 				$val = $formatType->getValue();
 				if ($val === 0) {
 					// return word count
 					return new IntegerType();
-				} elseif ($val === 1 || $val === 2) {
+				} elseif (in_array($val, [1, 2], true)) {
 					// return [word] or [offset => word]
 					return new ArrayType(new IntegerType(), new StringType());
 				}

src/Type/Regex/RegexGroupParser.php

@@ -711,7 +711,7 @@ private function getLiteralValue(TreeNode $node, ?array &$onlyLiterals, bool $ap
 			}
 		}
 
-		if ($token === 'anchor' || $token === 'match_point_reset') {
+		if (in_array($token, ['anchor', 'match_point_reset'], true)) {
 			return '';
 		}
 

tests/PHPStan/Build/OrChainIdenticalComparisonToInArrayRuleTest.php

@@ -0,0 +1,49 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Build;
+
+use PHPStan\File\FileHelper;
+use PHPStan\Node\Printer\ExprPrinter;
+use PHPStan\Node\Printer\Printer;
+use PHPStan\Rules\Rule;
+use PHPStan\Testing\RuleTestCase;
+
+/**
+ * @extends RuleTestCase<OrChainIdenticalComparisonToInArrayRule>
+ */
+final class OrChainIdenticalComparisonToInArrayRuleTest extends RuleTestCase
+{
+
+	protected function getRule(): Rule
+	{
+		return new OrChainIdenticalComparisonToInArrayRule(new ExprPrinter(new Printer()), self::getContainer()->getByType(FileHelper::class), false);
+	}
+
+	public function testRule(): void
+	{
+		$this->analyse([__DIR__ . '/data/or-chain-identical-comparison.php'], [
+			[
+				'This chain of identical comparisons can be simplified using in_array().',
+				7,
+			],
+			[
+				'This chain of identical comparisons can be simplified using in_array().',
+				11,
+			],
+			[
+				'This chain of identical comparisons can be simplified using in_array().',
+				15,
+			],
+			[
+				'This chain of identical comparisons can be simplified using in_array().',
+				17,
+			],
+		]);
+	}
+
+	public function testFix(): void
+	{
+		$this->fix(__DIR__ . '/data/or-chain-identical-comparison.php', __DIR__ . '/data/or-chain-identical-comparison.php.fixed');
+	}
+
+}

tests/PHPStan/Build/data/or-chain-identical-comparison.php

@@ -0,0 +1,31 @@
+<?php
+
+if ($var === 'foo') {
+	echo 'ok';
+}
+
+if ($var === 'foo' || $var === 'bar') {
+	echo 'ok';
+}
+
+if ($var === 'foo' || $var === 'bar' || $var === 'buz') {
+	echo 'ok';
+}
+
+if ($var === 'foo' || $var === 'bar' || $var === 'buz') {
+	echo 'ok';
+} elseif ($var === 'foofoo' || $var === 'barbar' || $var === 'buzbuz') {
+	echo 'ok';
+}
+
+if ($var === 'foo' || $var === 'bar' || $var2 === 'buz') {
+	echo 'no';
+}
+
+if ($var === 'foo' || $var2 === 'bar' || $var === 'buz') {
+	echo 'no';
+}
+
+if ($var === 'foo' || $var2 === 'bar' || $var2 === 'buz') {
+	echo 'no';
+}