[Serializer] Encode empty objects as objects, not arrays

mcfedr · mcfedr · commit 889fa6a3936d · 2018-09-05T11:40:13.000+03:00
Allows Normalizers to return a representation of an empty object that the encoder recognizes as such.
diff --git a/src/Symfony/Component/Serializer/Encoder/CsvEncoder.php b/src/Symfony/Component/Serializer/Encoder/CsvEncoder.php
@@ -53,7 +53,7 @@ public function encode($data, $format, array $context = array())
     {
         $handle = fopen('php://temp,', 'w+');
 
-        if (!\is_array($data)) {
+        if (!(\is_array($data) || $data instanceof \Traversable)) {
             $data = array(array($data));
         } elseif (empty($data)) {
             $data = array(array());
@@ -185,10 +185,10 @@ public function supportsDecoding($format)
     /**
      * Flattens an array and generates keys including the path.
      */
-    private function flatten(array $array, array &$result, string $keySeparator, string $parentKey = '', bool $escapeFormulas = false)
+    private function flatten($array, array &$result, string $keySeparator, string $parentKey = '', bool $escapeFormulas = false)
     {
         foreach ($array as $key => $value) {
-            if (\is_array($value)) {
+            if (\is_array($value) || $value instanceof \Traversable) {
                 $this->flatten($value, $result, $keySeparator, $parentKey.$key.$keySeparator, $escapeFormulas);
             } else {
                 if ($escapeFormulas && \in_array(substr($value, 0, 1), $this->formulasStartCharacters, true)) {
@@ -219,7 +219,7 @@ private function getCsvOptions(array $context)
     /**
      * @return string[]
      */
-    private function extractHeaders(array $data)
+    private function extractHeaders($data)
     {
         $headers = array();
         $flippedHeaders = array();
diff --git a/src/Symfony/Component/Serializer/Encoder/YamlEncoder.php b/src/Symfony/Component/Serializer/Encoder/YamlEncoder.php
@@ -14,6 +14,7 @@
 use Symfony\Component\Serializer\Exception\RuntimeException;
 use Symfony\Component\Yaml\Dumper;
 use Symfony\Component\Yaml\Parser;
+use Symfony\Component\Yaml\Yaml;
 
 /**
  * Encodes YAML data.
@@ -46,6 +47,10 @@ public function encode($data, $format, array $context = array())
     {
         $context = array_merge($this->defaultContext, $context);
 
+        if (isset($context['array_objects'])) {
+            $context['yaml_flags'] |= Yaml::DUMP_OBJECT_AS_MAP;
+        }
+
         return $this->dumper->dump($data, $context['yaml_inline'], $context['yaml_indent'], $context['yaml_flags']);
     }
 
diff --git a/src/Symfony/Component/Serializer/Normalizer/AbstractObjectNormalizer.php b/src/Symfony/Component/Serializer/Normalizer/AbstractObjectNormalizer.php
@@ -119,6 +119,10 @@ public function normalize($object, $format = null, array $context = array())
             $data = $this->updateData($data, $attribute, $this->serializer->normalize($attributeValue, $format, $this->createChildContext($context, $attribute)), $class, $format, $context);
         }
 
+        if (isset($context['array_objects']) && !\count($data)) {
+            return new \ArrayObject();
+        }
+
         return $data;
     }
 
diff --git a/src/Symfony/Component/Serializer/Normalizer/NormalizerInterface.php b/src/Symfony/Component/Serializer/Normalizer/NormalizerInterface.php
@@ -29,7 +29,7 @@ interface NormalizerInterface
      * @param string $format  Format the normalization result will be encoded as
      * @param array  $context Context options for the normalizer
      *
-     * @return array|string|int|float|bool
+     * @return array|string|int|float|bool|\ArrayObject
      *
      * @throws InvalidArgumentException   Occurs when the object given is not an attempted type for the normalizer
      * @throws CircularReferenceException Occurs when the normalizer detects a circular reference when no circular
diff --git a/src/Symfony/Component/Serializer/Tests/Encoder/CsvEncoderTest.php b/src/Symfony/Component/Serializer/Tests/Encoder/CsvEncoderTest.php
@@ -276,6 +276,43 @@ public function testEncodeFormulasWithSettingsPassedInContext()
             )));
     }
 
+    public function testEncodeArrayObject()
+    {
+        $value = new \ArrayObject(array('foo' => 'hello', 'bar' => 'hey ho'));
+
+        $this->assertEquals(<<<'CSV'
+foo,bar
+hello,"hey ho"
+
+CSV
+            , $this->encoder->encode($value, 'csv'));
+
+        $value = new \ArrayObject();
+
+        $this->assertEquals("\n", $this->encoder->encode($value, 'csv'));
+    }
+
+    public function testEncodeNestedArrayObject()
+    {
+        $value = new \ArrayObject(array('foo' => new \ArrayObject(array('nested' => 'value')), 'bar' => new \ArrayObject(array('another' => 'word'))));
+
+        $this->assertEquals(<<<'CSV'
+foo.nested,bar.another
+value,word
+
+CSV
+            , $this->encoder->encode($value, 'csv'));
+    }
+
+    public function testEncodeEmptyArrayObject()
+    {
+        $value = new \ArrayObject();
+        $this->assertEquals("\n", $this->encoder->encode($value, 'csv'));
+
+        $value = array('foo' => new \ArrayObject());
+        $this->assertEquals("\n\n", $this->encoder->encode($value, 'csv'));
+    }
+
     public function testSupportsDecoding()
     {
         $this->assertTrue($this->encoder->supportsDecoding('csv'));
diff --git a/src/Symfony/Component/Serializer/Tests/Encoder/JsonEncodeTest.php b/src/Symfony/Component/Serializer/Tests/Encoder/JsonEncodeTest.php
@@ -46,6 +46,8 @@ public function encodeProvider()
         return array(
             array(array(), '[]', array()),
             array(array(), '{}', array('json_encode_options' => JSON_FORCE_OBJECT)),
+            array(new \ArrayObject(), '{}', array()),
+            array(new \ArrayObject(array('foo' => 'bar')), '{"foo":"bar"}', array()),
         );
     }
 
diff --git a/src/Symfony/Component/Serializer/Tests/Encoder/XmlEncoderTest.php b/src/Symfony/Component/Serializer/Tests/Encoder/XmlEncoderTest.php
@@ -47,6 +47,26 @@ public function testEncodeScalar()
         $this->assertEquals($expected, $this->encoder->encode($obj, 'xml'));
     }
 
+    public function testEncodeArrayObject()
+    {
+        $obj = new \ArrayObject(array('foo' => 'bar'));
+
+        $expected = '<?xml version="1.0"?>'."\n".
+            '<response><foo>bar</foo></response>'."\n";
+
+        $this->assertEquals($expected, $this->encoder->encode($obj, 'xml'));
+    }
+
+    public function testEncodeEmptyArrayObject()
+    {
+        $obj = new \ArrayObject();
+
+        $expected = '<?xml version="1.0"?>'."\n".
+            '<response/>'."\n";
+
+        $this->assertEquals($expected, $this->encoder->encode($obj, 'xml'));
+    }
+
     public function testSetRootNodeName()
     {
         $obj = new ScalarDummy();
diff --git a/src/Symfony/Component/Serializer/Tests/Encoder/YamlEncoderTest.php b/src/Symfony/Component/Serializer/Tests/Encoder/YamlEncoderTest.php
@@ -28,6 +28,8 @@ public function testEncode()
 
         $this->assertEquals('foo', $encoder->encode('foo', 'yaml'));
         $this->assertEquals('{ foo: 1 }', $encoder->encode(array('foo' => 1), 'yaml'));
+        $this->assertEquals('null', $encoder->encode(new \ArrayObject(array('foo' => 1)), 'yaml'));
+        $this->assertEquals('{ foo: 1 }', $encoder->encode(new \ArrayObject(array('foo' => 1)), 'yaml', array('array_objects' => true)));
     }
 
     public function testSupportsEncoding()
diff --git a/src/Symfony/Component/Serializer/Tests/Normalizer/AbstractObjectNormalizerTest.php b/src/Symfony/Component/Serializer/Tests/Normalizer/AbstractObjectNormalizerTest.php
@@ -161,12 +161,24 @@ public function testExtraAttributesException()
             'allow_extra_attributes' => false,
         ));
     }
+
+    public function testNormalizeEmptyObject()
+    {
+        $normalizer = new AbstractObjectNormalizerDummy();
+
+        $normalizedData = $normalizer->normalize(new EmptyDummy());
+        $this->assertEquals(array(), $normalizedData);
+
+        $normalizedData = $normalizer->normalize(new EmptyDummy(), 'any', array('array_objects' => true));
+        $this->assertEquals(new \ArrayObject(), $normalizedData);
+    }
 }
 
 class AbstractObjectNormalizerDummy extends AbstractObjectNormalizer
 {
     protected function extractAttributes($object, $format = null, array $context = array())
     {
+        return array();
     }
 
     protected function getAttributeValue($object, $attribute, $format = null, array $context = array())
@@ -196,6 +208,10 @@ class Dummy
     public $baz;
 }
 
+class EmptyDummy
+{
+}
+
 class AbstractObjectNormalizerWithMetadata extends AbstractObjectNormalizer
 {
     public function __construct()
diff --git a/src/Symfony/Component/Serializer/Tests/Normalizer/PropertyNormalizerTest.php b/src/Symfony/Component/Serializer/Tests/Normalizer/PropertyNormalizerTest.php
@@ -157,6 +157,11 @@ public function testIgnoredAttributes()
             array(),
             $this->normalizer->normalize($obj, 'any')
         );
+
+        $this->assertEquals(
+            new \ArrayObject(),
+            $this->normalizer->normalize($obj, 'any', array('array_objects' => true))
+        );
     }
 
     public function testGroupsNormalize()
diff --git a/src/Symfony/Component/Serializer/Tests/SerializerTest.php b/src/Symfony/Component/Serializer/Tests/SerializerTest.php
@@ -15,6 +15,8 @@
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\PropertyInfo\Extractor\ReflectionExtractor;
 use Symfony\Component\Serializer\Encoder\JsonEncoder;
+use Symfony\Component\Serializer\Encoder\XmlEncoder;
+use Symfony\Component\Serializer\Encoder\YamlEncoder;
 use Symfony\Component\Serializer\Mapping\ClassDiscriminatorFromClassMetadata;
 use Symfony\Component\Serializer\Mapping\ClassDiscriminatorMapping;
 use Symfony\Component\Serializer\Mapping\ClassMetadata;
@@ -182,6 +184,19 @@ public function testSerializeArrayOfScalars()
         $this->assertEquals(json_encode($data), $result);
     }
 
+    public function testSerializeEmpty()
+    {
+        $serializer = new Serializer(array(new ObjectNormalizer()), array('json' => new JsonEncoder()));
+        $data = array('foo' => new \stdClass());
+
+        //Old buggy behaviour
+        $result = $serializer->serialize($data, 'json');
+        $this->assertEquals('{"foo":[]}', $result);
+
+        $result = $serializer->serialize($data, 'json', array('array_objects' => true));
+        $this->assertEquals('{"foo":{}}', $result);
+    }
+
     /**
      * @expectedException \Symfony\Component\Serializer\Exception\UnexpectedValueException
      */

Original file line number	Diff line number	Diff line change
`@@ -119,6 +119,10 @@ public function normalize($object, $format = null, array $context = array())`
`119`	`119`	`$data = $this->updateData($data, $attribute, $this->serializer->normalize($attributeValue, $format, $this->createChildContext($context, $attribute)), $class, $format, $context);`
`120`	`120`	`}`
`121`	`121`
	`122`	`+ if (isset($context['array_objects']) && !\count($data)) {`
	`123`	`+ return new \ArrayObject();`
	`124`	`+ }`
	`125`	`+`
`122`	`126`	`return $data;`
`123`	`127`	`}`
`124`	`128`
Original file line number	Diff line number	Diff line change
`@@ -29,7 +29,7 @@ interface NormalizerInterface`
`29`	`29`	`* @param string $format Format the normalization result will be encoded as`
`30`	`30`	`* @param array $context Context options for the normalizer`
`31`	`31`	`*`
`32`		`- * @return array\|string\|int\|float\|bool`
	`32`	`+ * @return array\|string\|int\|float\|bool\|\ArrayObject`
`33`	`33`	`*`
`34`	`34`	`* @throws InvalidArgumentException Occurs when the object given is not an attempted type for the normalizer`
`35`	`35`	`* @throws CircularReferenceException Occurs when the normalizer detects a circular reference when no circular`
Original file line number	Diff line number	Diff line change
`@@ -46,6 +46,8 @@ public function encodeProvider()`
`46`	`46`	`return array(`
`47`	`47`	`array(array(), '[]', array()),`
`48`	`48`	`array(array(), '{}', array('json_encode_options' => JSON_FORCE_OBJECT)),`
	`49`	`+ array(new \ArrayObject(), '{}', array()),`
	`50`	`+ array(new \ArrayObject(array('foo' => 'bar')), '{"foo":"bar"}', array()),`
`49`	`51`	`);`
`50`	`52`	`}`
`51`	`53`
Original file line number	Diff line number	Diff line change
`@@ -28,6 +28,8 @@ public function testEncode()`
`28`	`28`
`29`	`29`	`$this->assertEquals('foo', $encoder->encode('foo', 'yaml'));`
`30`	`30`	`$this->assertEquals('{ foo: 1 }', $encoder->encode(array('foo' => 1), 'yaml'));`
	`31`	`+ $this->assertEquals('null', $encoder->encode(new \ArrayObject(array('foo' => 1)), 'yaml'));`
	`32`	`+ $this->assertEquals('{ foo: 1 }', $encoder->encode(new \ArrayObject(array('foo' => 1)), 'yaml', array('array_objects' => true)));`
`31`	`33`	`}`
`32`	`34`
`33`	`35`	`public function testSupportsEncoding()`
Original file line number	Diff line number	Diff line change
`@@ -161,12 +161,24 @@ public function testExtraAttributesException()`
`161`	`161`	`'allow_extra_attributes' => false,`
`162`	`162`	`));`
`163`	`163`	`}`
	`164`	`+`
	`165`	`+ public function testNormalizeEmptyObject()`
	`166`	`+ {`
	`167`	`+ $normalizer = new AbstractObjectNormalizerDummy();`
	`168`	`+`
	`169`	`+ $normalizedData = $normalizer->normalize(new EmptyDummy());`
	`170`	`+ $this->assertEquals(array(), $normalizedData);`
	`171`	`+`
	`172`	`+ $normalizedData = $normalizer->normalize(new EmptyDummy(), 'any', array('array_objects' => true));`
	`173`	`+ $this->assertEquals(new \ArrayObject(), $normalizedData);`
	`174`	`+ }`
`164`	`175`	`}`
`165`	`176`
`166`	`177`	`class AbstractObjectNormalizerDummy extends AbstractObjectNormalizer`
`167`	`178`	`{`
`168`	`179`	`protected function extractAttributes($object, $format = null, array $context = array())`
`169`	`180`	`{`
	`181`	`+ return array();`
`170`	`182`	`}`
`171`	`183`
`172`	`184`	`protected function getAttributeValue($object, $attribute, $format = null, array $context = array())`
`@@ -196,6 +208,10 @@ class Dummy`
`196`	`208`	`public $baz;`
`197`	`209`	`}`
`198`	`210`
	`211`	`+class EmptyDummy`
	`212`	`+{`
	`213`	`+}`
	`214`	`+`
`199`	`215`	`class AbstractObjectNormalizerWithMetadata extends AbstractObjectNormalizer`
`200`	`216`	`{`
`201`	`217`	`public function __construct()`