fix

src/Type/ExponentiateHelper.php

@@ -87,13 +87,13 @@ private static function exponentiateConstantScalar(ConstantScalarType $base, Typ
 if ($exponent->getMin() !== null) {
 $min = self::pow($base->getValue(), $exponent->getMin());
 if ($min === null) {
-return null;
+return new ErrorType();
 }
 }
 if ($exponent->getMax() !== null) {
 $max = self::pow($base->getValue(), $exponent->getMax());
 if ($max === null) {
-return null;
+return new ErrorType();
 }
 }
 
@@ -104,9 +104,8 @@ private static function exponentiateConstantScalar(ConstantScalarType $base, Typ
 
 if ($exponent instanceof ConstantScalarType) {
 $result = self::pow($base->getValue(), $exponent->getValue());
-
 if ($result === null) {
-return null;
+return new ErrorType();
 }
 
 if (is_int($result)) {

tests/PHPStan/Analyser/nsrt/pow.php

@@ -112,8 +112,8 @@ function doFoo(int $intA, int $intB, string $s, bool $bool, $numericS, float $fl
 assertType('int', pow($intA, 1));
 assertType('int', $intA ** '1');
 
-assertType('*ERROR*', pow($intA, $s));
-assertType('*ERROR*', $intA ** $s);
+assertType('(float|int)', pow($intA, $s));
+assertType('(float|int)', $intA ** $s);
 
 assertType('(float|int)', pow($intA, $bool)); // could be int
 assertType('(float|int)', $intA ** $bool); // could be int
@@ -161,11 +161,11 @@ function doFoo(int $intA, int $intB, string $s, bool $bool, $numericS, float $fl
 
 assertType('NAN', pow(-1,5.5));
 
-assertType('*ERROR*', pow($s, 0));
-assertType('*ERROR*', $s ** '0');
-assertType('*ERROR*', $s ** false);
-assertType('*ERROR*', pow($s, 1));
-assertType('*ERROR*', $s ** '1');
+assertType('1', pow($s, 0));
+assertType('1', $s ** '0');
+assertType('1', $s ** false);
+assertType('(float|int)', pow($s, 1));
+assertType('(float|int)', $s ** '1');
 assertType('*ERROR*', $s ** $arr);
 assertType('*ERROR*', $s ** []);