Do not report non existent offset for invalid ones

Author: VincentLanglet

src/Rules/Arrays/NonexistentOffsetInArrayDimFetchCheck.php

@@ -12,7 +12,9 @@
 use PHPStan\Rules\RuleLevelHelper;
 use PHPStan\Type\BenevolentUnionType;
 use PHPStan\Type\ErrorType;
+use PHPStan\Type\NeverType;
 use PHPStan\Type\Type;
+use PHPStan\Type\TypeCombinator;
 use PHPStan\Type\TypeUtils;
 use PHPStan\Type\VerbosityLevel;
 use function count;
@@ -59,7 +61,13 @@ public function check(
 			return [];
 		}
 
-		if ($type->hasOffsetValueType($dimType)->no()) {
+		// Invalid dim types are already reported by InvalidKeyInArrayDimFetchRule and InvalidKeyInArrayItemRule.
+		$validDimType = TypeCombinator::intersect(AllowedArrayKeysTypes::getType(), $dimType);
+		if ($validDimType instanceof NeverType) {
+			return [];
+		}
+
+		if ($type->hasOffsetValueType($validDimType)->no()) {
 			return [
 				RuleErrorBuilder::message(sprintf('Offset %s does not exist on %s.', $dimType->describe(count($dimType->getConstantStrings()) > 0 ? VerbosityLevel::precise() : VerbosityLevel::value()), $type->describe(VerbosityLevel::value())))
 					->identifier('offsetAccess.notFound')
@@ -81,23 +89,23 @@ public function check(
 					$this->reportPossiblyNonexistentGeneralArrayOffset
 					&& $innerType->isArray()->yes()
 					&& !$innerType->isConstantArray()->yes()
-					&& !$innerType->hasOffsetValueType($dimType)->yes()
+					&& !$innerType->hasOffsetValueType($validDimType)->yes()
 				) {
 					$report = true;
 					break;
 				}
 				if (
 					$this->reportPossiblyNonexistentConstantArrayOffset
 					&& $innerType->isConstantArray()->yes()
-					&& !$innerType->hasOffsetValueType($dimType)->yes()
+					&& !$innerType->hasOffsetValueType($validDimType)->yes()
 				) {
 					$report = true;
 					break;
 				}
-				if ($dimType instanceof BenevolentUnionType) {
-					$flattenedInnerTypes = [$dimType];
+				if ($validDimType instanceof BenevolentUnionType) {
+					$flattenedInnerTypes = [$validDimType];
 				} else {
-					$flattenedInnerTypes = TypeUtils::flattenTypes($dimType);
+					$flattenedInnerTypes = TypeUtils::flattenTypes($validDimType);
 				}
 				foreach ($flattenedInnerTypes as $innerDimType) {
 					if (

tests/PHPStan/Rules/Arrays/NonexistentOffsetInArrayDimFetchRuleTest.php

@@ -193,10 +193,6 @@ public function testStrings(): void
 				'Offset 12.34 does not exist on \'foo\'.',
 				13,
 			],
-			[
-				'Offset int|object might not exist on \'foo\'.',
-				16,
-			],
 			[
 				'Offset \'foo\' might not exist on array|string.',
 				24,
@@ -205,10 +201,6 @@ public function testStrings(): void
 				'Offset 12.34 might not exist on array|string.',
 				28,
 			],
-			[
-				'Offset int|object might not exist on array|string.',
-				32,
-			],
 		]);
 	}