[PHP] CountOnNullRector cannot handle global scope

[fsok]

Subject	Details
Rector version	0.6.x-dev@40b50a6
PHP version	7.4
Full Command	bin/rector -c ../rector_test/rector_count_on_null.yaml process ../rector_test/src/count_on_null/count_on_null_fail.php --dry-run --debug

Current Behaviour

Rector 0.6.x-dev@40b50a6
Config file: ../rector_test/rector_count_on_null.yaml

before ../rector_test/src/count_on_null/count_on_null_fail.php
PHP Warning:  count(): Parameter must be an array or an object that implements Countable in /home/fsok/src/rector_test/src/count_on_null/count_on_null_fail.php on line 4
after ../rector_test/src/count_on_null/count_on_null_fail.php
[parsing] ../rector_test/src/count_on_null/count_on_null_fail.php
[refactoring] ../rector_test/src/count_on_null/count_on_null_fail.php
    [applying] Rector\Php71\Rector\FuncCall\CountOnNullRector
PHP Fatal error:  Uncaught TypeError: Return value of Rector\NodeTypeResolver\NodeTypeResolver::getScopeNode() must implement interface PhpParser\Node, null returned in /home/fsok/src/rector/packages/NodeTypeResolver/src/NodeTypeResolver.php:640
Stack trace:
#0 /home/fsok/src/rector/packages/NodeTypeResolver/src/NodeTypeResolver.php(648): Rector\NodeTypeResolver\NodeTypeResolver->getScopeNode(Object(PhpParser\Node\Expr\Variable))
#1 /home/fsok/src/rector/packages/NodeTypeResolver/src/NodeTypeResolver.php(608): Rector\NodeTypeResolver\NodeTypeResolver->getVariableUsages(Object(PhpParser\Node\Expr\Variable))
#2 /home/fsok/src/rector/packages/NodeTypeResolver/src/NodeTypeResolver.php(265): Rector\NodeTypeResolver\NodeTypeResolver->correctPregMatchType(Object(PhpParser\Node\Expr\Variable), Object(PHPStan\Type\NullType))
#3 /home/fsok/src/rector/src/Rector/AbstractRector/NodeTypeResolverTrait.php(91): Rector\NodeTypeResolver\NodeTypeResolver->isCountableType(Object(PhpParser\Node\Expr\Variable))
#4 /home/fsok/src/rector/packages/Ph in /home/fsok/src/rector/packages/NodeTypeResolver/src/NodeTypeResolver.php on line 640

#rector_count_on_null.yaml                                                                                                                             
services:
    Rector\Php71\Rector\FuncCall\CountOnNullRector: ~

Minimal PHP Code Causing Issue

<?php

$x = null;
count($x);

Expected Behaviour

CountOnNullRector should be applied successfully.

[TomasVotruba]

Resolved by #2435