fix(entity-refs): Allow partial references in resolveReference (#20)

* fix: Require one entity key instead of all

* fix: Add entity validation tests

Author: ldiego08

src/Types/EntityObjectType.php

@@ -111,7 +111,7 @@ private function validateReferenceKeys($ref)
         Utils::invariant(isset($ref['__typename']), 'Type name must be provided in the reference.');
 
         $refKeys = array_keys($ref);
-        $refContainsKeys = count(array_intersect($this->getKeyFields(), $refKeys)) === count($this->getKeyFields());
+        $refContainsKeys = !empty(array_intersect($this->getKeyFields(), $refKeys));
 
         Utils::invariant($refContainsKeys, 'Key fields are missing from the entity reference.');
     }

test/EntitiesTest.php

@@ -86,6 +86,56 @@ public function testResolvingEntityReference()
         $this->assertEquals($expectedRef, $actualRef);
     }
 
+    public function testResolvingEntityReferenceWithoutAllKeys()
+    {
+        $expectedRef = [
+            'id' => 1,
+            'email' => '[email protected]',
+            'firstName' => 'Luke',
+            'lastName' => 'Skywalker',
+            '__typename' => 'User'
+        ];
+
+        $userType = new EntityObjectType([
+            'name' => 'User',
+            'keyFields' => ['id', 'email'],
+            'fields' => [
+                'id' => ['type' => Type::int()],
+                'email' => ['type' => Type::string()],
+                'firstName' => ['type' => Type::string()],
+                'lastName' => ['type' => Type::string()]
+            ],
+            '__resolveReference' => function () use ($expectedRef) {
+                return $expectedRef;
+            }
+        ]);
+
+        $actualRef = $userType->resolveReference(['email' => '[email protected]', '__typename' => 'User']);
+
+        $this->assertEquals($expectedRef, $actualRef);
+    }
+
+    public function testResolvingEntityReferenceWithoutAnyKeys()
+    {
+        $userType = new EntityObjectType([
+            'name' => 'User',
+            'keyFields' => ['id', 'email'],
+            'fields' => [
+                'id' => ['type' => Type::int()],
+                'email' => ['type' => Type::string()],
+                'firstName' => ['type' => Type::string()],
+                'lastName' => ['type' => Type::string()]
+            ],
+            '__resolveReference' => function () {
+                return null;
+            }
+        ]);
+
+        $this->expectException(InvariantViolation::class);
+
+        $userType->resolveReference(['__typename' => 'User']);
+    }
+
     public function testCreatingEntityRefType()
     {
         $userTypeKeyFields = ['id', 'email'];