refactor: simplify schema id value fetching

Author: DannyvdSluijs

src/JsonSchema/Constraints/TypeCheck/LooseTypeCheck.php

@@ -44,7 +44,7 @@ public static function propertyExists($value, $property)
             return property_exists($value, $property);
         }
 
-        return array_key_exists($property, $value);
+        return is_array($value) && array_key_exists($property, $value);
     }
 
     public static function propertyCount($value)

src/JsonSchema/Validator.php

@@ -13,6 +13,7 @@
 
 use JsonSchema\Constraints\BaseConstraint;
 use JsonSchema\Constraints\Constraint;
+use JsonSchema\Constraints\TypeCheck\LooseTypeCheck;
 
 /**
  * A JsonSchema Constraint
@@ -59,12 +60,9 @@ public function validate(&$value, $schema = null, $checkMode = null)
         }
 
         // add provided schema to SchemaStorage with internal URI to allow internal $ref resolution
-        if (is_object($schema) && property_exists($schema, 'id')) {
-            $schemaURI = $schema->id;
-        } elseif (is_array($schema) && array_key_exists('id', $schema)) {
-            $schemaURI = $schema['id'];
-        } else {
-            $schemaURI = SchemaStorage::INTERNAL_PROVIDED_SCHEMA_URI;
+        $schemaURI = SchemaStorage::INTERNAL_PROVIDED_SCHEMA_URI;
+        if (LooseTypeCheck::propertyExists($schema, 'id')) {
+            $schemaURI = LooseTypeCheck::propertyGet($schema, 'id');
         }
         $this->factory->getSchemaStorage()->addSchema($schemaURI, $schema);