[applying] Rector\Php71\Rector\BinaryOp\BinaryOpBetweenNumberAndStringRector throw NotImplementedException

[yuzuofu]

Subject	Details
Rector version	v0.6.14
PHP version	PHP 7.4
Full Command	vendor/bin/rector process ./demo.php --set php71 --only "Rector\Php71\Rector\BinaryOp\BinaryOpBetweenNumberAndStringRector" --debug
Demo link	https://github.com/yuzuofu/rector-test/blob/master/demo.php
rector.yaml	no rector.yaml

Current Behaviour

[parsing] demo.php
[refactoring] demo.php
[applying] Rector\Php71\Rector\BinaryOp\BinaryOpBetweenNumberAndStringRector

Fatal error: Uncaught Rector\Exception\NotImplementedException in /var/www/info/vendor/rector/rector/packages/NodeTypeResolver/src/PerNodeTypeResolver/ScalarTypeResolver.php:45
Stack trace:
#0 /var/www/info/vendor/rector/rector/packages/NodeTypeResolver/src/NodeTypeResolver.php(366): Rector\NodeTypeResolver\PerNodeTypeResolver\ScalarTypeResolver->resolve(Object(PhpParser\Node\Scalar\Encapsed))
#1 /var/www/info/vendor/rector/rector/packages/NodeTypeResolver/src/NodeTypeResolver.php(178): Rector\NodeTypeResolver\NodeTypeResolver->resolveFirstType(Object(PhpParser\Node\Scalar\Encapsed))
#2 /var/www/info/vendor/rector/rector/packages/NodeTypeResolver/src/TypeAnalyzer/ArrayTypeAnalyzer.php(64): Rector\NodeTypeResolver\NodeTypeResolver->resolve(Object(PhpParser\Node\Scalar\Encapsed))
#3 /var/www/info/vendor/rector/rector/packages/NodeTypeResolver/src/NodeTypeResolver.php(486): Rector\NodeTypeResolver\TypeAnalyzer\ArrayTypeAnalyzer->isArrayType(Object(PhpParser\Node\Scalar\Encapsed))
#4 /var/www/info/vendor/rector/rector/package in /var/www/info/vendor/rector/rector/packages/NodeTypeResolver/src/PerNodeTypeResolver/ScalarTypeResolver.php on line 45

Minimal PHP Code Causing Issue

<?php 

// put file content here
$a = "test";
$b = "that is test";
assert($b=="this is $a");

Expected Behaviour

no behaviour