Description
The "Null reference" will mark a variable returned from a function (a static method at least, didn't test other functions or methods) as possible null, when the method never returns a null value. This is checked via an instanceof statement, but the inspection doesn't recognize or correctly handle this statement.
| Plugin | Php Inspections (EA Extended) 4.0.4.1 |
| Language level | PHP 7.2 |
Current behaviour
See the following code:
class A
{
/**
* @param A|null $a
*
* @return A
*/
public static function create(A $a = null)
{
if ($a instanceof A) {
return $a;
}
return new A();
}
public function foo()
{
print 'bar';
}
}
function test()
{
$a = A::create();
$a->foo();
}In the method test() the statement $a->foo(); will be marked with a warning "Null pointer exception may occur here". When you inspect the create method you can easily see that the method never returns null and the PhpDoc also documents this.
Expected behaviour
$a->foo() should not be marked with the warning "Null pointer exception may occur here".
When you change if ($a instanceof A) { into if ($a) { or if ($a !== null) { then the warning is not added and the inspection correctly identifies that create never returns null.
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