Avoid new HasOffsetValueType being intersected with oversized array

Author: ondrejmirtes

phpstan-baseline.neon

@@ -1170,6 +1170,11 @@ parameters:
 			count: 3
 			path: src/Type/IntersectionType.php
 
+		-
+			message: "#^Doing instanceof PHPStan\\\\Type\\\\ArrayType is error\\-prone and deprecated\\. Use Type\\:\\:isArray\\(\\) or Type\\:\\:getArrays\\(\\) instead\\.$#"
+			count: 1
+			path: src/Type/IntersectionType.php
+
 		-
 			message: "#^Doing instanceof PHPStan\\\\Type\\\\BooleanType is error\\-prone and deprecated\\. Use Type\\:\\:isBoolean\\(\\) instead\\.$#"
 			count: 1
@@ -1180,6 +1185,11 @@ parameters:
 			count: 2
 			path: src/Type/IntersectionType.php
 
+		-
+			message: "#^Doing instanceof PHPStan\\\\Type\\\\Constant\\\\ConstantStringType is error\\-prone and deprecated\\. Use Type\\:\\:getConstantStrings\\(\\) instead\\.$#"
+			count: 1
+			path: src/Type/IntersectionType.php
+
 		-
 			message: "#^Doing instanceof PHPStan\\\\Type\\\\IntersectionType is error\\-prone and deprecated\\.$#"
 			count: 4

src/Type/Constant/ConstantArrayTypeBuilder.php

@@ -128,6 +128,7 @@ public function setOffsetValueType(?Type $offsetType, Type $valueType, bool $opt
 
 				if (count($this->keyTypes) > self::ARRAY_COUNT_LIMIT) {
 					$this->degradeToGeneralArray = true;
+					$this->oversized = true;
 				}
 
 				return;
@@ -194,6 +195,7 @@ public function setOffsetValueType(?Type $offsetType, Type $valueType, bool $opt
 
 				if (count($this->keyTypes) > self::ARRAY_COUNT_LIMIT) {
 					$this->degradeToGeneralArray = true;
+					$this->oversized = true;
 				}
 
 				return;

src/Type/IntersectionType.php

@@ -28,6 +28,7 @@
 use PHPStan\Type\Accessory\AccessoryType;
 use PHPStan\Type\Accessory\NonEmptyArrayType;
 use PHPStan\Type\Constant\ConstantIntegerType;
+use PHPStan\Type\Constant\ConstantStringType;
 use PHPStan\Type\Generic\TemplateType;
 use PHPStan\Type\Generic\TemplateTypeMap;
 use PHPStan\Type\Generic\TemplateTypeVariance;
@@ -722,6 +723,30 @@ public function getOffsetValueType(Type $offsetType): Type
 
 	public function setOffsetValueType(?Type $offsetType, Type $valueType, bool $unionValues = true): Type
 	{
+		if ($this->isOversizedArray()->yes()) {
+			return $this->intersectTypes(static function (Type $type) use ($offsetType, $valueType, $unionValues): Type {
+				// avoid new HasOffsetValueType being intersected with oversized array
+				if (!$type instanceof ArrayType) {
+					return $type->setOffsetValueType($offsetType, $valueType, $unionValues);
+				}
+
+				if (!$offsetType instanceof ConstantStringType && !$offsetType instanceof ConstantIntegerType) {
+					return $type->setOffsetValueType($offsetType, $valueType, $unionValues);
+				}
+
+				if (!$offsetType->isSuperTypeOf($type->getKeyType())->yes()) {
+					return $type->setOffsetValueType($offsetType, $valueType, $unionValues);
+				}
+
+				return TypeCombinator::intersect(
+					new ArrayType(
+						TypeCombinator::union($type->getKeyType(), $offsetType),
+						TypeCombinator::union($type->getItemType(), $valueType),
+					),
+					new NonEmptyArrayType(),
+				);
+			});
+		}
 		return $this->intersectTypes(static fn (Type $type): Type => $type->setOffsetValueType($offsetType, $valueType, $unionValues));
 	}