Corrected bcdiv and bcmul return types for PHP 8.

Author: khkramer

src/Type/Php/BcMathStringOrNullReturnTypeExtension.php

@@ -5,6 +5,7 @@
 use PhpParser\Node\Expr\FuncCall;
 use PhpParser\Node\Expr\UnaryMinus;
 use PHPStan\Analyser\Scope;
+use PHPStan\Php\PhpVersion;
 use PHPStan\Reflection\FunctionReflection;
 use PHPStan\Type\Accessory\AccessoryNumericStringType;
 use PHPStan\Type\Constant\ConstantBooleanType;
@@ -22,6 +23,14 @@
 class BcMathStringOrNullReturnTypeExtension implements \PHPStan\Type\DynamicFunctionReturnTypeExtension
 {
 
+	/** @var PhpVersion */
+ private $phpVersion;
+
+	public function __construct(PhpVersion $phpVersion)
+	{
+		$this->phpVersion = $phpVersion;
+	}
+
 	public function isFunctionSupported(FunctionReflection $functionReflection): bool
 	{
 		return in_array($functionReflection->getName(), ['bcdiv', 'bcmod', 'bcpowmod', 'bcsqrt'], true);
@@ -41,7 +50,7 @@ public function getTypeFromFunctionCall(FunctionReflection $functionReflection,
 
 		$defaultReturnType = new UnionType([$stringAndNumericStringType, new NullType()]);
 
-		if (isset($functionCall->args[1]) === false) {
+		if (isset($functionCall->args[1]) === false || $this->phpVersion->getVersionId() >= 80000) {
 			return $stringAndNumericStringType;
 		}
 
@@ -126,7 +135,7 @@ private function getTypeForBcSqrt(FuncCall $functionCall, Scope $scope): Type
 	}
 
 	/**
-	 * bcpowmod()
+	 * @see bcpowmod()
 	 * https://www.php.net/manual/en/function.bcpowmod.php
 	 * > Returns the result as a string, or FALSE if modulus is 0 or exponent is negative.
 	 * @param FuncCall $functionCall

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -122,7 +122,11 @@ public function dataFileAsserts(): iterable
 		yield from $this->gatherAssertTypes(__DIR__ . '/../Rules/Comparison/data/bug-2550.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-2899.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/preg_split.php');
-		yield from $this->gatherAssertTypes(__DIR__ . '/data/bcmath-dynamic-return.php');
+
+		if (PHP_VERSION_ID < 80000) {
+			yield from $this->gatherAssertTypes(__DIR__ . '/data/bcmath-dynamic-return.php');
+		}
+
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-3875.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-2611.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-3548.php');