Add note for substr() can return false on php 7.x on ClassLikeNameClassNameImportSkipVoter (#7438)

* Add note for substr() can return false on php 7.x on ClassLikeNameClassNameImportSkipVoter

* Add note for substr() can return false on php 7.x on ClassLikeNameClassNameImportSkipVoter

Author: samsonasik

rules/CodingStyle/ClassNameImport/ClassNameImportSkipVoter/ClassLikeNameClassNameImportSkipVoter.php

@@ -46,8 +46,12 @@ public function shouldSkip(File $file, FullyQualifiedObjectType $fullyQualifiedO
         $namespace = strtolower((string) $namespace);
 
         $shortNameLowered = $fullyQualifiedObjectType->getShortNameLowered();
-        $subClassName = substr($fullyQualifiedObjectType->getClassName(), 0, -strlen($fullyQualifiedObjectType->getShortName()) - 1);
-        $fullyQualifiedObjectTypeNamespace = strtolower((string) $subClassName);
+        /**
+         * on php 7.x, substr() result can return false, so force (string) is needed
+         * @see https://github.com/rectorphp/rector-src/pull/7436
+         */
+        $subClassName = (string) substr($fullyQualifiedObjectType->getClassName(), 0, -strlen($fullyQualifiedObjectType->getShortName()) - 1);
+        $fullyQualifiedObjectTypeNamespace = strtolower($subClassName);
 
         foreach ($classLikeNames as $classLikeName) {
             if (strtolower($classLikeName) !== $shortNameLowered) {