Linkage (#15)

Author: f3ath

src/Document/Document.php

@@ -80,7 +80,7 @@ public function setIncluded(IdentifiableResource ...$included)
         $this->included = $included;
     }
 
-    public function setIsSparse()
+    public function markSparse()
     {
         $this->is_sparse = true;
     }
@@ -108,36 +108,34 @@ private function enforceFullLinkage()
         if ($this->is_sparse || empty($this->included)) {
             return;
         }
-        foreach ($this->included as $resource) {
-            if (!$this->hasLinkTo($resource)) {
-                throw new \LogicException("Full linkage is required for $resource");
+        foreach ($this->included as $included_resource) {
+            if (!$this->hasLinkTo($included_resource)) {
+                throw new \LogicException("Full linkage is required for $included_resource");
             }
         }
     }
 
     private function hasLinkTo(IdentifiableResource $resource): bool
     {
-        foreach ($this->toDataItems() as $my_resource) {
-            if ($my_resource instanceof ResourceObject) {
-                if ($my_resource->hasRelationTo($resource)) {
-                    return true;
-                }
+        /** @var ResourceObject $my_resource */
+        foreach ($this->toResourceObjects() as $my_resource) {
+            if ($my_resource->hasRelationTo($resource)) {
+                return true;
             }
         }
         return false;
     }
 
-    /**
-     * @return IdentifiableResource[]
-     */
-    private function toDataItems(): array
+    private function toResourceObjects(): \Generator
     {
-        if ($this->data instanceof IdentifiableResource) {
-            return [$this->data];
+        if ($this->data instanceof ResourceObject) {
+            yield $this->data;
         } elseif (is_array($this->data)) {
-            return $this->data;
-        } else {
-            return [];
+            foreach ($this->data as $datum) {
+                if ($datum instanceof ResourceObject) {
+                    yield $datum;
+                }
+            }
         }
     }
 }

src/Document/Resource/Relationship/Linkage.php

@@ -54,6 +54,9 @@ public static function fromManyResourceIds(ResourceId ...$data): self
     public function isLinkedTo(IdentifiableResource $resource): bool
     {
         if ($this->data) {
+            if ($this->data instanceof ResourceId) {
+                return $this->data->isEqualTo($resource);
+            }
             foreach ($this->data as $my_resource) {
                 if ($resource->isEqualTo($my_resource)) {
                     return true;

test/Document/CompoundDocumentTest.php

@@ -102,7 +102,7 @@ public function testFullLinkageIsRequired()
     public function testFullLinkageIsNotRequiredIfSparse()
     {
         $doc = Document::fromResource(new NullData);
-        $doc->setIsSparse();
+        $doc->markSparse();
         $doc->setIncluded(
             new ResourceObject('apples', '1')
         );

test/Document/Resource/Relationship/LinkageTest.php

@@ -14,32 +14,34 @@
 
 namespace JsonApiPhp\JsonApi\Test\Document\Resource\Relationship;
 
+use JsonApiPhp\JsonApi\Document\Resource\NullData;
 use JsonApiPhp\JsonApi\Document\Resource\Relationship\Linkage;
 use JsonApiPhp\JsonApi\Document\Resource\ResourceId;
 use JsonApiPhp\JsonApi\Test\HasAssertEqualsAsJson;
+use phpDocumentor\Reflection\DocBlock\Tags\Link;
 use PHPUnit\Framework\TestCase;
 
 class LinkageTest extends TestCase
 {
     use HasAssertEqualsAsJson;
 
-    public function testNullLinkage()
+    public function testCanCreateNullLinkage()
     {
         $this->assertEqualsAsJson(
             null,
             Linkage::nullLinkage()
         );
     }
 
-    public function testEmptyArrayLinkage()
+    public function testCanCreateEmptyArrayLinkage()
     {
         $this->assertEqualsAsJson(
             [],
             Linkage::emptyArrayLinkage()
         );
     }
 
-    public function testFromResourceId()
+    public function testCanCreateFromResourceId()
     {
         $this->assertEqualsAsJson(
             [
@@ -50,7 +52,7 @@ public function testFromResourceId()
         );
     }
 
-    public function testFromResourceIds()
+    public function testCanCreateFromResourceIds()
     {
         $this->assertEqualsAsJson(
             [
@@ -66,4 +68,42 @@ public function testFromResourceIds()
             Linkage::fromManyResourceIds(new ResourceId('books', 'abc'), new ResourceId('squirrels', '123'))
         );
     }
+
+    public function testNullLinkageIsLinkedToNothing()
+    {
+        $apple = new ResourceId('apples', '1');
+        $this->assertFalse(Linkage::nullLinkage()->isLinkedTo($apple));
+        $this->assertFalse(Linkage::nullLinkage()->isLinkedTo(new NullData));
+    }
+
+    public function testEmptyArrayLinkageIsLinkedToNothing()
+    {
+        $apple = new ResourceId('apples', '1');
+        $this->assertFalse(Linkage::emptyArrayLinkage()->isLinkedTo($apple));
+        $this->assertFalse(Linkage::emptyArrayLinkage()->isLinkedTo(new NullData));
+    }
+
+    public function testSingleLinkageIsLinkedOnlyToItself()
+    {
+        $apple = new ResourceId('apples', '1');
+        $orange = new ResourceId('oranges', '1');
+
+        $linkage = Linkage::fromSingleResourceId($apple);
+
+        $this->assertTrue($linkage->isLinkedTo($apple));
+        $this->assertFalse($linkage->isLinkedTo($orange));
+    }
+
+    public function testMultiLinkageIsLinkedOnlyToItsMembers()
+    {
+        $apple = new ResourceId('apples', '1');
+        $orange = new ResourceId('oranges', '1');
+        $banana = new ResourceId('bananas', '1');
+
+        $linkage = Linkage::fromManyResourceIds($apple, $orange);
+
+        $this->assertTrue($linkage->isLinkedTo($apple));
+        $this->assertTrue($linkage->isLinkedTo($orange));
+        $this->assertFalse($linkage->isLinkedTo($banana));
+    }
 }