resolves #9

README.md

@@ -107,6 +107,13 @@ Adds operation to `JsonPatch`.
 #### `apply`
 Applies patch to `JSON`-decoded data.
 
+#### `setFlags`
+Alters default behavior.
+
+Available flag:
+
+* `JsonPatch::STRICT_MODE` Disallow converting empty array to object for key creation.
+
 ### `JsonPointer`
 
 #### `escapeSegment`

src/JsonPatch.php

@@ -19,6 +19,24 @@
  */
 class JsonPatch implements \JsonSerializable
 {
+    /**
+     * Disallow converting empty array to object for key creation
+     * @see JsonPointer::STRICT_MODE
+     */
+    const STRICT_MODE = 2;
+
+    private $flags = 0;
+
+    /**
+     * @param int $options
+     * @return $this
+     */
+    public function setFlags($options)
+    {
+        $this->flags = $options;
+        return $this;
+    }
+
     /** @var OpPath[] */
     private $operations = array();
 
@@ -118,26 +136,26 @@ public function apply(&$original, $stopOnError = true)
                 $pathItems = JsonPointer::splitPath($operation->path);
                 switch (true) {
                     case $operation instanceof Add:
-                        JsonPointer::add($original, $pathItems, $operation->value, false);
+                        JsonPointer::add($original, $pathItems, $operation->value, $this->flags);
                         break;
                     case $operation instanceof Copy:
                         $fromItems = JsonPointer::splitPath($operation->from);
                         $value = JsonPointer::get($original, $fromItems);
-                        JsonPointer::add($original, $pathItems, $value, false);
+                        JsonPointer::add($original, $pathItems, $value, $this->flags);
                         break;
                     case $operation instanceof Move:
                         $fromItems = JsonPointer::splitPath($operation->from);
                         $value = JsonPointer::get($original, $fromItems);
                         JsonPointer::remove($original, $fromItems);
-                        JsonPointer::add($original, $pathItems, $value, false);
+                        JsonPointer::add($original, $pathItems, $value, $this->flags);
                         break;
                     case $operation instanceof Remove:
                         JsonPointer::remove($original, $pathItems);
                         break;
                     case $operation instanceof Replace:
                         JsonPointer::get($original, $pathItems);
                         JsonPointer::remove($original, $pathItems);
-                        JsonPointer::add($original, $pathItems, $operation->value, false);
+                        JsonPointer::add($original, $pathItems, $operation->value, $this->flags);
                         break;
                     case $operation instanceof Test:
                         $value = JsonPointer::get($original, $pathItems);

src/JsonPointer.php

@@ -5,6 +5,16 @@
 
 class JsonPointer
 {
+    /**
+     * Create intermediate keys if they don't exist
+     */
+    const RECURSIVE_KEY_CREATION = 1;
+
+    /**
+     * Disallow converting empty array to object for key creation
+     */
+    const STRICT_MODE = 2;
+
     /**
      * @param string $key
      * @param bool $isURIFragmentId
@@ -76,10 +86,10 @@ private static function splitPathJsonString(array $pathItems)
      * @param mixed $holder
      * @param string[] $pathItems
      * @param mixed $value
-     * @param bool $recursively
+     * @param int $flags
      * @throws Exception
      */
-    public static function add(&$holder, $pathItems, $value, $recursively = true)
+    public static function add(&$holder, $pathItems, $value, $flags = self::RECURSIVE_KEY_CREATION)
     {
         $ref = &$holder;
         while (null !== $key = array_shift($pathItems)) {
@@ -89,7 +99,7 @@ public static function add(&$holder, $pathItems, $value, $recursively = true)
                         Exception::EMPTY_PROPERTY_NAME_UNSUPPORTED);
                 }
 
-                if ($recursively) {
+                if ($flags & self::RECURSIVE_KEY_CREATION) {
                     $ref = &$ref->$key;
                 } else {
                     if (!isset($ref->$key) && count($pathItems)) {
@@ -102,17 +112,17 @@ public static function add(&$holder, $pathItems, $value, $recursively = true)
                 $intKey = filter_var($key, FILTER_VALIDATE_INT);
                 if ($ref === null && (false === $intKey || $intKey !== 0)) {
                     $key = (string)$key;
-                    if ($recursively) {
+                    if ($flags & self::RECURSIVE_KEY_CREATION) {
                         $ref = new \stdClass();
                         $ref = &$ref->{$key};
                     } else {
                         throw new Exception('Non-existent path item: ' . $key);
                     }
-                } elseif ([] === $ref && false === $intKey && '-' !== $key) {
+                } elseif ([] === $ref && 0 === ($flags & self::STRICT_MODE) && false === $intKey && '-' !== $key) {
                     $ref = new \stdClass();
                     $ref = &$ref->{$key};
                 } else {
-                    if ($recursively && $ref === null) $ref = array();
+                    if ($flags & self::RECURSIVE_KEY_CREATION && $ref === null) $ref = array();
                     if ('-' === $key) {
                         $ref = &$ref[];
                     } else {
@@ -122,7 +132,7 @@ public static function add(&$holder, $pathItems, $value, $recursively = true)
                         if (false === $intKey) {
                             throw new Exception('Invalid key for array operation');
                         }
-                        if ($intKey > count($ref) && !$recursively) {
+                        if ($intKey > count($ref) && 0 === ($flags & self::RECURSIVE_KEY_CREATION)) {
                             throw new Exception('Index is greater than number of items in array');
                         } elseif ($intKey < 0) {
                             throw new Exception('Negative index');

tests/src/Issues/Issue9Test.php

@@ -2,7 +2,9 @@
 
 namespace Swaggest\JsonDiff\Tests\Issues;
 
+use Swaggest\JsonDiff\Exception;
 use Swaggest\JsonDiff\JsonDiff;
+use Swaggest\JsonDiff\JsonPatch;
 
 /**
  * @see https://github.com/swaggest/json-diff/issues/9
@@ -18,5 +20,9 @@ public function testPatchApply()
         $this->assertNotEquals($new, $old);
         $patch->apply($old);
         $this->assertEquals($new, $old);
+
+        $old = json_decode(json_encode(["emptyObject" => []]));
+        $this->setExpectedException(get_class(new Exception()), 'Invalid key for array operation');
+        $patch->setFlags(JsonPatch::STRICT_MODE)->apply($old);
     }
 }