Cross-linkage check (#19) (resolves #17)

Author: f3ath

src/Document/Document.php

@@ -109,9 +109,17 @@ private function enforceFullLinkage()
             return;
         }
         foreach ($this->included as $included_resource) {
-            if (!$this->hasLinkTo($included_resource)) {
-                throw new \LogicException("Full linkage is required for $included_resource");
+            if ($this->hasLinkTo($included_resource)) {
+                continue;
             }
+            /** @var IdentifiableResource $another_included_resource */
+            foreach ($this->included as $another_included_resource) {
+                if ($another_included_resource !== $included_resource
+                    && $another_included_resource->identifies($included_resource)) {
+                    continue 2;
+                }
+            }
+            throw new \LogicException("Full linkage is required for $included_resource");
         }
     }
 

test/Document/CompoundDocumentTest.php

@@ -113,6 +113,28 @@ public function testIncludedResourceMayBeIdentifiedByPrimaryData()
         $this->assertCanBeBuilt($doc);
     }
 
+    public function testIncludedResourceMayBeIdentifiedByAnotherIncludedResource()
+    {
+        /**
+         * BasketID identifies included BasketObject
+         * BasketObject identifies included AppleObject
+         */
+        $apple = new ResourceObject('apples', '1');
+        $apple->setAttribute('color', 'red');
+        $basket = new ResourceObject('basket', '1');
+        $basket->setRelationship(
+            'fruits',
+            Relationship::fromLinkage(
+                Linkage::fromManyResourceIds(
+                    $apple->toId()
+                )
+            )
+        );
+        $doc = Document::fromResource($basket->toId());
+        $doc->setIncluded($apple, $basket);
+        $this->assertCanBeBuilt($doc);
+    }
+
     private function convertToArray($object): array
     {
         return json_decode(json_encode($object), true);