From a3b3fc92069e08f5eb6fff1e8140596e2b7738d0 Mon Sep 17 00:00:00 2001
From: Jasper Zonneveld <jasper@swis.nl>
Date: Mon, 18 May 2020 11:56:06 +0200
Subject: [PATCH] Serialize classes as objects

---
 CHANGELOG.md           |  4 ++-
 src/Document.php       | 55 +++++++++++++++++++++++++++++-------------
 src/Jsonapi.php        | 29 +++++++++++++++++++++-
 src/Links.php          |  4 +--
 src/Meta.php           |  4 +--
 tests/DocumentTest.php | 19 +++++++++++++++
 6 files changed, 92 insertions(+), 23 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 26987eb..666a13e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,7 +6,9 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ## [Unreleased]
 
-* Nothing
+### Fixed
+
+* `Document`, `Jsonapi`, `Links` and `Meta` classes will be serialized as object when empty.
 
 ## [1.1.0] - 2020-03-06
 
diff --git a/src/Document.php b/src/Document.php
index 281f5d4..a9f4c68 100644
--- a/src/Document.php
+++ b/src/Document.php
@@ -160,21 +160,6 @@ public function setData(DataInterface $data)
         return $this;
     }
 
-    /**
-     * Specify data which should be serialized to JSON.
-     *
-     * @see  http://php.net/manual/en/jsonserializable.jsonserialize.php
-     *
-     * @return mixed data which can be serialized by <b>json_encode</b>,
-     *               which is a value of any type other than a resource
-     *
-     * @since 5.4.0
-     */
-    public function jsonSerialize()
-    {
-        return $this->toArray();
-    }
-
     /**
      * @return array
      */
@@ -186,7 +171,7 @@ public function toArray(): array
             $document['links'] = $this->getLinks()->toArray();
         }
 
-        if (!empty($this->getData())) {
+        if ($this->getData() !== null) {
             $document['data'] = $this->data->toJsonApiArray();
         }
 
@@ -199,7 +184,7 @@ public function toArray(): array
         }
 
         if ($this->hasErrors()) {
-            $document['errors'] = $this->errors->toArray();
+            $document['errors'] = $this->getErrors()->toArray();
         }
 
         if ($this->getJsonapi() !== null) {
@@ -208,4 +193,40 @@ public function toArray(): array
 
         return $document;
     }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @return object
+     */
+    public function jsonSerialize()
+    {
+        $document = [];
+
+        if ($this->getLinks() !== null) {
+            $document['links'] = $this->getLinks();
+        }
+
+        if ($this->getData() !== null) {
+            $document['data'] = $this->data->toJsonApiArray();
+        }
+
+        if ($this->getIncluded()->isNotEmpty()) {
+            $document['included'] = $this->getIncluded()->toJsonApiArray();
+        }
+
+        if ($this->getMeta() !== null) {
+            $document['meta'] = $this->getMeta();
+        }
+
+        if ($this->hasErrors()) {
+            $document['errors'] = $this->getErrors();
+        }
+
+        if ($this->getJsonapi() !== null) {
+            $document['jsonapi'] = $this->getJsonapi();
+        }
+
+        return (object) $document;
+    }
 }
diff --git a/src/Jsonapi.php b/src/Jsonapi.php
index 649c2ba..055e587 100644
--- a/src/Jsonapi.php
+++ b/src/Jsonapi.php
@@ -2,9 +2,12 @@
 
 namespace Swis\JsonApi\Client;
 
+use Illuminate\Contracts\Support\Arrayable;
+use Illuminate\Contracts\Support\Jsonable;
+use JsonSerializable;
 use Swis\JsonApi\Client\Concerns\HasMeta;
 
-class Jsonapi
+class Jsonapi implements Arrayable, Jsonable, JsonSerializable
 {
     use HasMeta;
 
@@ -32,6 +35,8 @@ public function getVersion()
     }
 
     /**
+     * {@inheritdoc}
+     *
      * @return array
      */
     public function toArray(): array
@@ -48,4 +53,26 @@ public function toArray(): array
 
         return $array;
     }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @param int $options
+     *
+     * @return false|string
+     */
+    public function toJson($options = 0)
+    {
+        return json_encode($this->jsonSerialize(), $options);
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @return object
+     */
+    public function jsonSerialize()
+    {
+        return (object) $this->toArray();
+    }
 }
diff --git a/src/Links.php b/src/Links.php
index acce020..2983aaa 100644
--- a/src/Links.php
+++ b/src/Links.php
@@ -134,10 +134,10 @@ public function toJson($options = 0)
     /**
      * {@inheritdoc}
      *
-     * @return array|mixed
+     * @return object
      */
     public function jsonSerialize()
     {
-        return $this->toArray();
+        return (object) $this->toArray();
     }
 }
diff --git a/src/Meta.php b/src/Meta.php
index 2bfcfbc..991ebc2 100644
--- a/src/Meta.php
+++ b/src/Meta.php
@@ -129,10 +129,10 @@ public function toJson($options = 0)
     /**
      * {@inheritdoc}
      *
-     * @return array|mixed
+     * @return object
      */
     public function jsonSerialize()
     {
-        return $this->toArray();
+        return (object) $this->toArray();
     }
 }
diff --git a/tests/DocumentTest.php b/tests/DocumentTest.php
index 3a2f1e5..4ce5a0b 100644
--- a/tests/DocumentTest.php
+++ b/tests/DocumentTest.php
@@ -229,4 +229,23 @@ public function it_returns_only_filled_properties_in_toArray()
             $document->toArray()
         );
     }
+
+    /**
+     * @test
+     */
+    public function it_serializes_empty_members_as_empty_objects()
+    {
+        $document = new Document();
+
+        $this->assertEquals('{}', json_encode($document));
+
+        $document->setData(new Collection());
+        $document->setErrors(new ErrorCollection());
+        $document->setIncluded(new Collection());
+        $document->setJsonapi(new Jsonapi());
+        $document->setLinks(new Links([]));
+        $document->setMeta(new Meta([]));
+
+        $this->assertEquals('{"links":{},"data":[],"meta":{},"jsonapi":{}}', json_encode($document));
+    }
 }