Context::getCurrentPath() returns indexes of list items

src/Context.php

@@ -253,6 +253,9 @@ public function getCurrentPath(): array
 
         $paths = [];
         foreach ($this->metadataStack as $metadata) {
+            if ($metadata instanceof ClassMetadata && $metadata->positionInList !== null) {
+                array_unshift($paths, $metadata->positionInList);
+            }
             if ($metadata instanceof PropertyMetadata) {
                 array_unshift($paths, $metadata->name);
             }

src/GraphNavigator/SerializationGraphNavigator.php

@@ -116,6 +116,14 @@ public function initialize(VisitorInterface $visitor, Context $context): void
      */
     public function accept($data, ?array $type = null)
     {
+        // Element could be one of the element list
+        $positionInList = null;
+        if (isset($type['position_in_list'])) {
+            $positionInList = $type['position_in_list'];
+            unset($type['position_in_list']);
+            $type = $type ?: null;
+        }
+
         // If the type was not given, we infer the most specific type from the
         // input data in serialization mode.
         if (null === $type) {
@@ -219,6 +227,11 @@ public function accept($data, ?array $type = null)
                 $metadata = $this->metadataFactory->getMetadataForClass($type['name']);
                 \assert($metadata instanceof ClassMetadata);
 
+                if ($positionInList !== null) {
+                    $metadata = clone $metadata;
+                    $metadata->positionInList = $positionInList;
+                }
+
                 if ($metadata->usingExpression && null === $this->expressionExclusionStrategy) {
                     throw new ExpressionLanguageRequiredException(sprintf('To use conditional exclude/expose in %s you must configure the expression language.', $metadata->name));
                 }

src/JsonSerializationVisitor.php

@@ -89,6 +89,7 @@ public function visitArray(array $data, array $type)
 
         $elType = $this->getElementType($type);
         foreach ($data as $k => $v) {
+            $elType['position_in_list'] = $k;
             try {
                 $v = $this->navigator->accept($v, $elType);
             } catch (NotAcceptableException $e) {

src/Metadata/ClassMetadata.php

@@ -84,6 +84,13 @@ class ClassMetadata extends MergeableClassMetadata
      */
     public $isMap = false;
 
+    /**
+     * @internal
+     *
+     * @var int|null
+     */
+    public $positionInList = null;
+
     /**
      * @var bool
      */

tests/Serializer/ContextTest.php

@@ -62,24 +62,29 @@ public function testSerializationContextPathAndDepth()
         $exclusionStrategy->expects($this->any())
             ->method('shouldSkipProperty')
             ->with($this->anything(), $this->callback(static function (SerializationContext $context) use ($self, $objects) {
-                $expectedDepth = $expectedPath = null;
+                $expectedCurrentPath = $expectedDepth = $expectedPath = null;
 
                 if ($context->getObject() === $objects[0]) {
                     $expectedDepth = 1;
                     $expectedPath = 'JMS\Serializer\Tests\Fixtures\Node';
+                    $expectedCurrentPath = [];
                 } elseif ($context->getObject() === $objects[1]) {
                     $expectedDepth = 2;
                     $expectedPath = 'JMS\Serializer\Tests\Fixtures\Node -> JMS\Serializer\Tests\Fixtures\Node';
+                    $expectedCurrentPath = ['children', 0];
                 } elseif ($context->getObject() === $objects[2]) {
                     $expectedDepth = 2;
                     $expectedPath = 'JMS\Serializer\Tests\Fixtures\Node -> JMS\Serializer\Tests\Fixtures\Node';
+                    $expectedCurrentPath = ['children', 1];
                 } elseif ($context->getObject() === $objects[3]) {
                     $expectedDepth = 3;
                     $expectedPath = 'JMS\Serializer\Tests\Fixtures\Node -> JMS\Serializer\Tests\Fixtures\Node -> JMS\Serializer\Tests\Fixtures\Node';
+                    $expectedCurrentPath = ['children', 1, 'children', 0];
                 }
 
                 $self->assertEquals($expectedDepth, $context->getDepth(), 'shouldSkipProperty depth');
                 $self->assertEquals($expectedPath, $context->getPath(), 'shouldSkipProperty path');
+                $self->assertEquals($expectedCurrentPath, $context->getCurrentPath(), 'Unexpected context current path');
 
                 return true;
             }))