Use isArray instead of array supertype checks

Author: herndlm

src/Reflection/InitializerExprTypeResolver.php

@@ -927,9 +927,7 @@ public function getPlusType(Expr $left, Expr $right, callable $getTypeCallback):
 			return TypeCombinator::union(...$resultTypes);
 		}
 
-		$arrayType = new ArrayType(new MixedType(), new MixedType());
-
-		if ($arrayType->isSuperTypeOf($leftType)->yes() && $arrayType->isSuperTypeOf($rightType)->yes()) {
+		if ($leftType->isArray()->yes() && $rightType->isArray()->yes()) {
 			if ($leftType->getIterableKeyType()->equals($rightType->getIterableKeyType())) {
 				// to preserve BenevolentUnionType
 				$keyType = $leftType->getIterableKeyType();

src/Type/Php/CountFunctionTypeSpecifyingExtension.php

@@ -10,9 +10,7 @@
 use PHPStan\Analyser\TypeSpecifierContext;
 use PHPStan\Reflection\FunctionReflection;
 use PHPStan\Type\Accessory\NonEmptyArrayType;
-use PHPStan\Type\ArrayType;
 use PHPStan\Type\FunctionTypeSpecifyingExtension;
-use PHPStan\Type\MixedType;
 use function count;
 use function in_array;
 
@@ -39,7 +37,7 @@ public function specifyTypes(
 		TypeSpecifierContext $context,
 	): SpecifiedTypes
 	{
-		if (!(new ArrayType(new MixedType(), new MixedType()))->isSuperTypeOf($scope->getType($node->getArgs()[0]->value))->yes()) {
+		if (!$scope->getType($node->getArgs()[0]->value)->isArray()->yes()) {
 			return new SpecifiedTypes([], []);
 		}
 

src/Type/Php/MbConvertEncodingFunctionReturnTypeExtension.php

@@ -9,7 +9,6 @@
 use PHPStan\Type\ArrayType;
 use PHPStan\Type\DynamicFunctionReturnTypeExtension;
 use PHPStan\Type\IntegerType;
-use PHPStan\Type\MixedType;
 use PHPStan\Type\StringType;
 use PHPStan\Type\Type;
 
@@ -34,7 +33,7 @@ public function getTypeFromFunctionCall(
 
 		$argType = $scope->getType($functionCall->getArgs()[0]->value);
 		$isString = (new StringType())->isSuperTypeOf($argType);
-		$isArray = (new ArrayType(new MixedType(), new MixedType()))->isSuperTypeOf($argType);
+		$isArray = $argType->isArray();
 		$compare = $isString->compareTo($isArray);
 		if ($compare === $isString) {
 			return new StringType();

src/Type/Php/ReplaceFunctionsDynamicReturnTypeExtension.php

@@ -91,10 +91,9 @@ private function getPreliminarilyResolvedTypeFromFunctionCall(
 		}
 
 		$stringType = new StringType();
-		$arrayType = new ArrayType(new MixedType(), new MixedType());
 
 		$isStringSuperType = $stringType->isSuperTypeOf($subjectArgumentType);
-		$isArraySuperType = $arrayType->isSuperTypeOf($subjectArgumentType);
+		$isArraySuperType = $subjectArgumentType->isArray();
 		$compareSuperTypes = $isStringSuperType->compareTo($isArraySuperType);
 		if ($compareSuperTypes === $isStringSuperType) {
 			return $stringType;