Non-numeric strings in pow() lead to error

Author: staabm

src/Type/ExponentiateHelper.php

@@ -2,6 +2,7 @@
 
 namespace PHPStan\Type;
 
+use PHPStan\Type\Accessory\AccessoryNumericStringType;
 use PHPStan\Type\Constant\ConstantFloatType;
 use PHPStan\Type\Constant\ConstantIntegerType;
 use function is_float;
@@ -24,14 +25,20 @@ public static function exponentiate(Type $base, Type $exponent): Type
 			return new NeverType();
 		}
 
-		$allowedExponentTypes = new UnionType([
+		$allowedOperandTypes = new UnionType([
 			new IntegerType(),
 			new FloatType(),
-			new StringType(),
+			new IntersectionType([
+				new StringType(),
+				new AccessoryNumericStringType(),
+			]),
 			new BooleanType(),
 			new NullType(),
 		]);
-		if (!$allowedExponentTypes->isSuperTypeOf($exponent)->yes()) {
+		if (!$allowedOperandTypes->isSuperTypeOf($exponent)->yes()) {
+			return new ErrorType();
+		}
+		if (!$allowedOperandTypes->isSuperTypeOf($base)->yes()) {
 			return new ErrorType();
 		}
 

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('(float|int)', pow($intA, $s));
-	assertType('(float|int)', $intA ** $s);
+	assertType('*ERROR*', pow($intA, $s));
+	assertType('*ERROR*', $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('1', pow($s, 0));
-	assertType('1', $s ** '0');
-	assertType('1', $s ** false);
-	assertType('(float|int)', pow($s, 1));
-	assertType('(float|int)', $s ** '1');
+	assertType('*ERROR*', pow($s, 0));
+	assertType('*ERROR*', $s ** '0');
+	assertType('*ERROR*', $s ** false);
+	assertType('*ERROR*', pow($s, 1));
+	assertType('*ERROR*', $s ** '1');
 	assertType('*ERROR*', $s ** $arr);
 	assertType('*ERROR*', $s ** []);
 
@@ -177,3 +177,23 @@ function doFoo(int $intA, int $intB, string $s, bool $bool, $numericS, float $fl
 	assertType('*ERROR*', $bool ** $arr);
 	assertType('*ERROR*', $bool ** []);
 };
+
+function invalidConstantOperands(): void {
+	assertType('*ERROR*', 'a' ** 1);
+	assertType('*ERROR*',  1 ** 'a');
+
+	assertType('*ERROR*', [] ** 1);
+	assertType('*ERROR*',  1 ** []);
+
+	assertType('*ERROR*', (new \stdClass()) ** 1);
+	assertType('*ERROR*',  1 ** (new \stdClass()));
+}
+
+function validConstantOperands(): void {
+	assertType('1', '1' ** 1);
+	assertType('1',  1 ** '1');
+	assertType('1',  '1' ** '1');
+
+	assertType('1', true ** 1);
+	assertType('1',  1 ** false);
+}