From 9a795a6620d96a985a7c46f59753cd10892221eb Mon Sep 17 00:00:00 2001
From: Simon Podlipsky <simon@podlipsky.net>
Date: Wed, 17 Jul 2024 09:04:39 +0200
Subject: [PATCH] feat(json): allow normalizing stdClass to `{}`

- allow `JSON_FORCE_OBJECT` flag
---
 src/Normalizer/Formatter/JsonFormatter.php    |  7 +++++++
 src/Normalizer/JsonNormalizer.php             |  4 +++-
 .../Integration/Normalizer/NormalizerTest.php | 21 +++++++++++++++----
 3 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/src/Normalizer/Formatter/JsonFormatter.php b/src/Normalizer/Formatter/JsonFormatter.php
index 6e46220d..f97b3455 100644
--- a/src/Normalizer/Formatter/JsonFormatter.php
+++ b/src/Normalizer/Formatter/JsonFormatter.php
@@ -17,6 +17,7 @@
 use function is_scalar;
 use function json_encode;
 
+use const JSON_FORCE_OBJECT;
 use const JSON_THROW_ON_ERROR;
 
 /** @internal */
@@ -45,6 +46,12 @@ public function format(mixed $value): void
         } elseif ($value instanceof EmptyObject) {
             $this->write('{}');
         } elseif (is_iterable($value)) {
+            if ($value === [] && $this->jsonEncodingOptions & JSON_FORCE_OBJECT) {
+                $this->write('{}');
+
+                return;
+
+            }
             // Note: when a generator is formatted, it is considered as a list
             // if its first key is 0. This is done early because the first JSON
             // character for an array differs from the one for an object, and we
diff --git a/src/Normalizer/JsonNormalizer.php b/src/Normalizer/JsonNormalizer.php
index 872955ed..3ccb8702 100644
--- a/src/Normalizer/JsonNormalizer.php
+++ b/src/Normalizer/JsonNormalizer.php
@@ -14,6 +14,7 @@
 use function is_resource;
 use function stream_get_contents;
 
+use const JSON_FORCE_OBJECT;
 use const JSON_HEX_AMP;
 use const JSON_HEX_APOS;
 use const JSON_HEX_QUOT;
@@ -34,7 +35,8 @@
  */
 final class JsonNormalizer implements Normalizer
 {
-    private const ACCEPTABLE_JSON_OPTIONS = JSON_HEX_QUOT
+    private const ACCEPTABLE_JSON_OPTIONS = JSON_FORCE_OBJECT
+    | JSON_HEX_QUOT
     | JSON_HEX_TAG
     | JSON_HEX_AMP
     | JSON_HEX_APOS
diff --git a/tests/Integration/Normalizer/NormalizerTest.php b/tests/Integration/Normalizer/NormalizerTest.php
index 80bbb59e..e761ce2d 100644
--- a/tests/Integration/Normalizer/NormalizerTest.php
+++ b/tests/Integration/Normalizer/NormalizerTest.php
@@ -30,6 +30,7 @@
 
 use function array_merge;
 
+use const JSON_FORCE_OBJECT;
 use const JSON_HEX_TAG;
 use const JSON_THROW_ON_ERROR;
 
@@ -194,6 +195,21 @@ public static function normalize_basic_values_yields_expected_output_data_provid
             'expected json' => '{"foo":"foo","bar":"bar"}',
         ];
 
+        yield 'empty stdClass' => [
+            'input' => (fn () => new stdClass())(),
+            'expected array' => [],
+            'expected json' => '[]',
+        ];
+
+        yield 'empty stdClass kept as object in json' => [
+            'input' => (fn () => new stdClass())(),
+            'expected array' => [],
+            'expected json' => '{}',
+            [],
+            [],
+            JSON_FORCE_OBJECT
+        ];
+
         yield 'ArrayObject' => [
             'input' => new ArrayObject(['foo' => 'foo', 'bar' => 'bar']),
             'expected array' => [
@@ -1148,16 +1164,13 @@ public function test_json_transformer_will_always_throw_on_error(): void
 
     public function test_json_transformer_only_accepts_acceptable_json_options(): void
     {
-        $normalizer = $this->mapperBuilder()->normalizer(Format::json())->withOptions(JSON_FORCE_OBJECT);
-        self::assertSame(JSON_THROW_ON_ERROR, (fn () => $this->jsonEncodingOptions)->call($normalizer));
-
         $normalizer = $this->mapperBuilder()->normalizer(Format::json())->withOptions(JSON_PARTIAL_OUTPUT_ON_ERROR);
         self::assertSame(JSON_THROW_ON_ERROR, (fn () => $this->jsonEncodingOptions)->call($normalizer));
 
         $normalizer = $this->mapperBuilder()->normalizer(Format::json())->withOptions(JSON_PRETTY_PRINT);
         self::assertSame(JSON_THROW_ON_ERROR, (fn () => $this->jsonEncodingOptions)->call($normalizer));
 
-        $normalizer = $this->mapperBuilder()->normalizer(Format::json())->withOptions(JSON_FORCE_OBJECT | JSON_PARTIAL_OUTPUT_ON_ERROR | JSON_PRETTY_PRINT);
+        $normalizer = $this->mapperBuilder()->normalizer(Format::json())->withOptions(JSON_PARTIAL_OUTPUT_ON_ERROR | JSON_PRETTY_PRINT);
         self::assertSame(JSON_THROW_ON_ERROR, (fn () => $this->jsonEncodingOptions)->call($normalizer));
     }
 }