phpstan · VincentLanglet · May 24, 2025
diff --git a/conf/config.level3.neon b/conf/config.level3.neon
@@ -35,13 +35,15 @@ services:
 		class: PHPStan\Rules\Arrays\InvalidKeyInArrayDimFetchRule
 		arguments:
 			reportMaybes: %reportMaybes%
+			reportCastedArrayKey: %reportCastedArrayKey%
 		tags:
 			- phpstan.rules.rule
 
 	-
 		class: PHPStan\Rules\Arrays\InvalidKeyInArrayItemRule
 		arguments:
 			reportMaybes: %reportMaybes%
+			reportCastedArrayKey: %reportCastedArrayKey%
 		tags:
 			- phpstan.rules.rule
 

diff --git a/conf/config.neon b/conf/config.neon
@@ -63,6 +63,7 @@ parameters:
 	reportStaticMethodSignatures: false
 	reportWrongPhpDocTypeInVarTag: false
 	reportAnyTypeWideningInVarTag: false
+	reportCastedArrayKey: false
 	reportPossiblyNonexistentGeneralArrayOffset: false
 	reportPossiblyNonexistentConstantArrayOffset: false
 	checkMissingOverrideMethodAttribute: false

diff --git a/conf/parametersSchema.neon b/conf/parametersSchema.neon
@@ -75,6 +75,7 @@ parametersSchema:
 	reportStaticMethodSignatures: bool()
 	reportWrongPhpDocTypeInVarTag: bool()
 	reportAnyTypeWideningInVarTag: bool()
+	reportCastedArrayKey: bool()
 	reportPossiblyNonexistentGeneralArrayOffset: bool()
 	reportPossiblyNonexistentConstantArrayOffset: bool()
 	checkMissingOverrideMethodAttribute: bool()

diff --git a/src/Rules/Arrays/AllowedArrayKeysTypes.php b/src/Rules/Arrays/AllowedArrayKeysTypes.php
@@ -21,8 +21,15 @@
 final class AllowedArrayKeysTypes
 {
 
-	public static function getType(): Type
+	public static function getType(bool $strict = false): Type
 	{
+		if ($strict) {
+			return new UnionType([
+				new IntegerType(),
+				new StringType(),
+			]);
+		}
+
 		return new UnionType([
 			new IntegerType(),
 			new StringType(),

diff --git a/src/Rules/Arrays/InvalidKeyInArrayDimFetchRule.php b/src/Rules/Arrays/InvalidKeyInArrayDimFetchRule.php
@@ -22,6 +22,7 @@ final class InvalidKeyInArrayDimFetchRule implements Rule
 	public function __construct(
 		private RuleLevelHelper $ruleLevelHelper,
 		private bool $reportMaybes,
+		private bool $reportCastedArrayKey,
 	)
 	{
 	}
@@ -42,18 +43,19 @@ public function processNode(Node $node, Scope $scope): array
 			return [];
 		}
 
+		$reportCastedArrayKey = $this->reportCastedArrayKey;
 		$varType = $this->ruleLevelHelper->findTypeToCheck(
 			$scope,
 			$node->var,
 			'',
-			static fn (Type $varType): bool => $varType->isArray()->no() || AllowedArrayKeysTypes::getType()->isSuperTypeOf($dimensionType)->yes(),
+			static fn (Type $varType): bool => $varType->isArray()->no() || AllowedArrayKeysTypes::getType($reportCastedArrayKey)->isSuperTypeOf($dimensionType)->yes(),
 		)->getType();
 
 		if ($varType instanceof ErrorType || $varType->isArray()->no()) {
 			return [];
 		}
 
-		$isSuperType = AllowedArrayKeysTypes::getType()->isSuperTypeOf($dimensionType);
+		$isSuperType = AllowedArrayKeysTypes::getType($this->reportCastedArrayKey)->isSuperTypeOf($dimensionType);
 		if ($isSuperType->yes() || ($isSuperType->maybe() && !$this->reportMaybes)) {
 			return [];
 		}

diff --git a/src/Rules/Arrays/InvalidKeyInArrayItemRule.php b/src/Rules/Arrays/InvalidKeyInArrayItemRule.php
@@ -16,7 +16,7 @@
 final class InvalidKeyInArrayItemRule implements Rule
 {
 
-	public function __construct(private bool $reportMaybes)
+	public function __construct(private bool $reportMaybes, private bool $reportCastedArrayKey)
 	{
 	}
 
@@ -32,7 +32,7 @@ public function processNode(Node $node, Scope $scope): array
 		}
 
 		$dimensionType = $scope->getType($node->key);
-		$isSuperType = AllowedArrayKeysTypes::getType()->isSuperTypeOf($dimensionType);
+		$isSuperType = AllowedArrayKeysTypes::getType($this->reportCastedArrayKey)->isSuperTypeOf($dimensionType);
 		if ($isSuperType->no()) {
 			return [
 				RuleErrorBuilder::message(

diff --git a/tests/PHPStan/Rules/Arrays/InvalidKeyInArrayDimFetchRuleTest.php b/tests/PHPStan/Rules/Arrays/InvalidKeyInArrayDimFetchRuleTest.php
@@ -13,10 +13,12 @@
 class InvalidKeyInArrayDimFetchRuleTest extends RuleTestCase
 {
 
+	private bool $reportCastedArrayKey = false;
+
 	protected function getRule(): Rule
 	{
 		$ruleLevelHelper = new RuleLevelHelper($this->createReflectionProvider(), true, false, true, false, false, false, true);
-		return new InvalidKeyInArrayDimFetchRule($ruleLevelHelper, true);
+		return new InvalidKeyInArrayDimFetchRule($ruleLevelHelper, true, $this->reportCastedArrayKey);
 	}
 
 	public function testInvalidKey(): void
@@ -61,6 +63,69 @@ public function testInvalidKey(): void
 		]);
 	}
 
+	public function testInvalidKeyReportingCastedArrayKey(): void
+	{
+		$this->reportCastedArrayKey = true;
+		$this->analyse([__DIR__ . '/data/invalid-key-array-dim-fetch.php'], [
+			[
+				'Invalid array key type null.',
+				6,
+			],
+			[
+				'Invalid array key type DateTimeImmutable.',
+				7,
+			],
+			[
+				'Invalid array key type array.',
+				8,
+			],
+			[
+				'Invalid array key type float.',
+				10,
+			],
+			[
+				'Invalid array key type true.',
+				12,
+			],
+			[
+				'Invalid array key type false.',
+				13,
+			],
+			[
+				'Possibly invalid array key type string|null.',
+				17,
+			],
+			[
+				'Possibly invalid array key type stdClass|string.',
+				24,
+			],
+			[
+				'Invalid array key type DateTimeImmutable.',
+				31,
+			],
+			[
+				'Invalid array key type DateTimeImmutable.',
+				45,
+			],
+			[
+				'Invalid array key type DateTimeImmutable.',
+				46,
+			],
+			[
+				'Invalid array key type DateTimeImmutable.',
+				47,
+			],
+			[
+				'Invalid array key type stdClass.',
+				47,
+			],
+			[
+				'Invalid array key type DateTimeImmutable.',
+				48,
+			],
+		]);
+	}
+
 	public function testBug6315(): void
 	{
 		if (PHP_VERSION_ID < 80100) {
@@ -95,4 +160,20 @@ public function testBug6315(): void
 		]);
 	}
 
+	public function testUnsetFalseKey(): void
+	{
+		$this->reportCastedArrayKey = true;
+
+		$this->analyse([__DIR__ . '/data/unset-false-key.php'], [
+			[
+				'Invalid array key type false.',
+				6,
+			],
+			[
+				'Invalid array key type false.',
+				13,
+			],
+		]);
+	}
+
 }
diff --git a/tests/PHPStan/Rules/Arrays/InvalidKeyInArrayItemRuleTest.php b/tests/PHPStan/Rules/Arrays/InvalidKeyInArrayItemRuleTest.php
@@ -12,9 +12,11 @@
 class InvalidKeyInArrayItemRuleTest extends RuleTestCase
 {
 
+	private bool $reportCastedArrayKey = false;
+
 	protected function getRule(): Rule
 	{
-		return new InvalidKeyInArrayItemRule(true);
+		return new InvalidKeyInArrayItemRule(true, $this->reportCastedArrayKey);
 	}
 
 	public function testInvalidKey(): void
@@ -35,6 +37,29 @@ public function testInvalidKey(): void
 		]);
 	}
 
+	public function testInvalidKeyReportingCastedArrayKey(): void
+	{
+		$this->reportCastedArrayKey = true;
+		$this->analyse([__DIR__ . '/data/invalid-key-array-item.php'], [
+			[
+				'Invalid array key type null.',
+				12,
+			],
+			[
+				'Invalid array key type DateTimeImmutable.',
+				13,
+			],
+			[
+				'Invalid array key type array.',
+				14,
+			],
+			[
+				'Possibly invalid array key type stdClass|string.',
+				15,
+			],
+		]);
+	}
+
 	public function testInvalidKeyInList(): void
 	{
 		$this->analyse([__DIR__ . '/data/invalid-key-list.php'], [

diff --git a/tests/PHPStan/Rules/Arrays/data/unset-false-key.php b/tests/PHPStan/Rules/Arrays/data/unset-false-key.php
@@ -0,0 +1,16 @@
+<?php declare(strict_types=1);
+
+namespace UnsetFalseKey;
+
+/** @var array<int, int> $data */
+unset($data[false]);
+
+function test_remove_element(): void {
+	$modified = [1, 4, 6, 8];
+
+	// this would happen in the SUT
+	unset($modified[array_search(4, $modified, true)]);
+	unset($modified[array_search(5, $modified, true)]); // bug is here - will unset key `0` by accident
+
+	assert([1, 6, 8] === $modified); // actually is [6, 8]
+}