fix

Author: staabm

src/Type/Php/ArrayKeyExistsFunctionTypeSpecifyingExtension.php

@@ -122,6 +122,7 @@ public function specifyTypes(
 			&& !$arrayType->isArray()->yes()
 		) {
 			$type = new ArrayType(new MixedType(), new MixedType());
+			$type = $type->unsetOffset($keyType);
 			$context = $context->negate();
 		} else {
 			$type = new HasOffsetType($keyType);

tests/PHPStan/Analyser/nsrt/bug-13301-php8.php

@@ -9,7 +9,7 @@ function doFoo($mixed) {
 		assertType("non-empty-array&hasOffset('a')", $mixed);
 		echo "has-a";
 	} else {
-		assertType('array', $mixed); // could be array~hasOffset('a') after arrays got subtractable
+		assertType("array<mixed~'a', mixed>", $mixed);
 		echo "NO-a";
 	}
 	assertType('array', $mixed);
@@ -19,7 +19,7 @@ function doFooTrue($mixed) {
 	if (array_key_exists('a', $mixed) === true) {
 		assertType("non-empty-array&hasOffset('a')", $mixed);
 	} else {
-		assertType('array', $mixed); // could be array~hasOffset('a') after arrays got subtractable
+		assertType("array<mixed~'a', mixed>", $mixed);
 	}
 	assertType('array', $mixed);
 }
@@ -28,14 +28,14 @@ function doFooTruethy($mixed) {
 	if (array_key_exists('a', $mixed) == true) {
 		assertType("non-empty-array&hasOffset('a')", $mixed);
 	} else {
-		assertType('array', $mixed); // could be array~hasOffset('a') after arrays got subtractable
+		assertType("array<mixed~'a', mixed>", $mixed);
 	}
 	assertType('array', $mixed);
 }
 
 function doFooFalsey($mixed) {
 	if (array_key_exists('a', $mixed) == 0) {
-		assertType("array", $mixed);
+		assertType("array<mixed~'a', mixed>", $mixed);
 	} else {
 		assertType("non-empty-array&hasOffset('a')", $mixed);
 	}