Unset relation when null (singular) or empty array (plural)

Closes: #66

Author: JaZo

src/ItemHydrator.php

@@ -6,6 +6,8 @@
 use Illuminate\Support\Str;
 use Swis\JsonApi\Client\Exceptions\HydrationException;
 use Swis\JsonApi\Client\Interfaces\ItemInterface;
+use Swis\JsonApi\Client\Interfaces\ManyRelationInterface;
+use Swis\JsonApi\Client\Interfaces\OneRelationInterface;
 use Swis\JsonApi\Client\Interfaces\TypeMapperInterface;
 use Swis\JsonApi\Client\Relations\HasManyRelation;
 use Swis\JsonApi\Client\Relations\HasOneRelation;
@@ -76,6 +78,16 @@ protected function fillRelations(ItemInterface $item, array $attributes): void
 
             $relation = $this->getRelationFromItem($item, $availableRelation);
 
+            // The relation should be unset
+            if (
+                ($relation instanceof OneRelationInterface && $attributes[$availableRelation] === null) ||
+                ($relation instanceof ManyRelationInterface && $attributes[$availableRelation] === [])
+            ) {
+                $relation->dissociate();
+
+                return;
+            }
+
             // It is a valid relation
             if ($relation instanceof HasOneRelation) {
                 $this->hydrateHasOneRelation($relation, $attributes[$availableRelation]);

tests/ItemHydratorTest.php

@@ -102,6 +102,28 @@ public function it_hydrates_hasone_relationships_with_attributes()
         $this->assertArrayHasKey('hasone_relation', $item->toJsonApiArray()['relationships']);
     }
 
+    /**
+     * @test
+     */
+    public function it_dissociates_hasone_relationships_when_null()
+    {
+        $data = [
+            'hasone_relation' => null,
+        ];
+
+        $item = new WithRelationshipItem();
+        $item = $this->getItemHydrator()->hydrate($item, $data);
+
+        /** @var \Swis\JsonApi\Client\Relations\HasOneRelation $hasOne */
+        $hasOne = $item->getRelation('hasone_relation');
+        $this->assertInstanceOf(HasOneRelation::class, $hasOne);
+
+        $this->assertNull($hasOne->getIncluded());
+
+        $this->assertArrayHasKey('hasone_relation', $item->toJsonApiArray()['relationships']);
+        $this->assertNull($item->toJsonApiArray()['relationships']['hasone_relation']['data']);
+    }
+
     /**
      * @test
      */
@@ -174,6 +196,28 @@ public function it_hydrates_hasmany_relationships_with_attributes()
         $this->assertArrayHasKey('hasmany_relation', $item->toJsonApiArray()['relationships']);
     }
 
+    /**
+     * @test
+     */
+    public function it_dissociates_hasmany_relationships_when_empty_array()
+    {
+        $data = [
+            'hasmany_relation' => [],
+        ];
+
+        $item = new WithRelationshipItem();
+        $item = $this->getItemHydrator()->hydrate($item, $data);
+
+        /** @var \Swis\JsonApi\Client\Relations\HasManyRelation $hasMany */
+        $hasMany = $item->getRelation('hasmany_relation');
+        $this->assertInstanceOf(HasManyRelation::class, $hasMany);
+
+        $this->assertTrue($hasMany->getIncluded()->isEmpty());
+
+        $this->assertArrayHasKey('hasmany_relation', $item->toJsonApiArray()['relationships']);
+        $this->assertSame([], $item->toJsonApiArray()['relationships']['hasmany_relation']['data']);
+    }
+
     /**
      * @test
      */
@@ -228,6 +272,28 @@ public function it_hydrates_morphto_relationships_with_attributes()
         $this->assertArrayHasKey('morphto_relation', $item->toJsonApiArray()['relationships']);
     }
 
+    /**
+     * @test
+     */
+    public function it_dissociates_morphto_relationships_when_null()
+    {
+        $data = [
+            'morphto_relation' => null,
+        ];
+
+        $item = new WithRelationshipItem();
+        $item = $this->getItemHydrator()->hydrate($item, $data);
+
+        /** @var \Swis\JsonApi\Client\Relations\MorphToRelation $morphTo */
+        $morphTo = $item->getRelation('morphto_relation');
+        $this->assertInstanceOf(MorphToRelation::class, $morphTo);
+
+        $this->assertNull($morphTo->getIncluded());
+
+        $this->assertArrayHasKey('morphto_relation', $item->toJsonApiArray()['relationships']);
+        $this->assertNull($item->toJsonApiArray()['relationships']['morphto_relation']['data']);
+    }
+
     /**
      * @test
      */
@@ -350,6 +416,28 @@ public function it_hydrates_morphtomany_relationships_with_attributes()
         $this->assertArrayHasKey('morphtomany_relation', $item->toJsonApiArray()['relationships']);
     }
 
+    /**
+     * @test
+     */
+    public function it_dissociates_morphtomany_relationships_when_empty_array()
+    {
+        $data = [
+            'morphtomany_relation' => [],
+        ];
+
+        $item = new WithRelationshipItem();
+        $item = $this->getItemHydrator()->hydrate($item, $data);
+
+        /** @var \Swis\JsonApi\Client\Relations\MorphToManyRelation $morphToMany */
+        $morphToMany = $item->getRelation('morphtomany_relation');
+        $this->assertInstanceOf(MorphToManyRelation::class, $morphToMany);
+
+        $this->assertTrue($morphToMany->getIncluded()->isEmpty());
+
+        $this->assertArrayHasKey('morphtomany_relation', $item->toJsonApiArray()['relationships']);
+        $this->assertSame([], $item->toJsonApiArray()['relationships']['morphtomany_relation']['data']);
+    }
+
     /**
      * @test
      */