Set collection keys

src/Set.php

@@ -26,7 +26,8 @@
     Totem\Change\Modification,
 
     Totem\SetInterface,
-    Totem\AbstractSnapshot;
+    Totem\AbstractSnapshot,
+    Totem\Snapshot\CollectionSnapshot;
 
 /**
  * Represents a changeset
@@ -149,6 +150,14 @@ public function compute(AbstractSnapshot $old, AbstractSnapshot $new)
                 $this->changes[$key] = $result;
             }
         }
+
+        /*
+         * Collection tricky case : each changes should not be represented by
+         * its primary key, but by a numeric key. Because it is a collection, duh.
+         */
+        if ($old instanceof CollectionSnapshot && $new instanceof CollectionSnapshot) {
+            $this->changes = array_values($this->changes);
+        }
     }
 
     /**

src/Snapshot/CollectionSnapshot.php

@@ -33,6 +33,13 @@
  */
 class CollectionSnapshot extends AbstractSnapshot
 {
+    /**
+     * Collection of the new keys (extracted from the primary key) => old keys
+     *
+     * @var integer[]
+     */
+    private $link = [];
+
     /**
      * Construct the snapshot
      *
@@ -97,7 +104,10 @@ public function __construct($data, $pkey, array $options = [])
                 throw new InvalidArgumentException(sprintf('The key "%s" is not defined or readable in one of the elements of the collection', $pkey));
             }
 
-            $this->data[$accessor->getValue($value, $primary)] = $this->snapshot($value, $snapshot);
+            $primary = $accessor->getValue($value, $primary);
+
+            $this->link[$primary] = $key;
+            $this->data[$primary] = $this->snapshot($value, $snapshot);
         }
 
         parent::normalize();
@@ -122,5 +132,21 @@ private function snapshot($value, $class = null)
 
         return new $class($value);
     }
+
+    /**
+     * Returns the original key for the primary key $primary
+     *
+     * @param mixed $primary Primary key to search
+     *
+     * @return integer original key
+     * @throws InvalidArgumentException primary key not found
+     */
+    public function getOriginalKey($primary) {
+        if (!isset($this->link[$primary])) {
+            throw new InvalidArgumentException(sprintf('The primary key "%s" is not in the computed dataset', $primary));
+        }
+
+        return $this->link[$primary];
+    }
 }
 

test/SetTest.php

@@ -16,7 +16,8 @@
 use \PHPUnit_Framework_TestCase;
 
 use Totem\Snapshot\ArraySnapshot,
-    Totem\Snapshot\ObjectSnapshot;
+    Totem\Snapshot\ObjectSnapshot,
+    Totem\Snapshot\CollectionSnapshot;
 
 class SetTest extends \PHPUnit_Framework_TestCase
 {
@@ -180,5 +181,37 @@ public function testAlreadyComputedSetShouldNotRecompute()
 
         $set->compute($old, $new);
     }
+
+    public function testComputeCollections()
+    {
+        $old = $new = [['foo' => 'bar', 'baz' => 'fubar'], ['foo' => 'baz', 'baz' => 'fubar']];
+        $new[0]['baz'] = 'fubaz';
+
+        $old = new CollectionSnapshot($old, 'foo');
+        $new = new CollectionSnapshot($new, 'foo');
+
+        $set = new Set;
+        $set->compute($old, $new);
+
+        $this->assertContainsOnly('integer',array_keys(iterator_to_array($set)));
+    }
+
+    /** @dataProvider unaffectedSnapshotComputerProvider */
+    public function testUnaffectedCollections(AbstractSnapshot $origin, AbstractSnapshot $upstream)
+    {
+        $set = new Set;
+        $set->compute($origin, $upstream);
+
+        $this->assertNotContainsOnly('integer',array_keys(iterator_to_array($set)));
+    }
+
+    public function unaffectedSnapshotComputerProvider()
+    {
+        $old = ['foo' => 'bar', 'baz' => 'fubar'];
+
+        return [[new CollectionSnapshot([$old], 'foo'), new ArraySnapshot($old)],
+                [new ArraySnapshot($old), new CollectionSnapshot([$old], 'foo')],
+                [new ArraySnapshot($old), new ArraySnapshot(array_merge($old, ['baz' => 'fubaz']))]];
+    }
 }
 

test/Snapshot/CollectionSnapshotTest.php

@@ -96,5 +96,22 @@ public function allValidProvider()
         return [[true],
                 [false]];
     }
+
+    /**
+     * @expectedException        InvalidArgumentException
+     * @expectedExceptionMessage The primary key "baz" is not in the computed dataset
+     */
+    public function testOriginalKeyNotFound()
+    {
+        $snapshot = new CollectionSnapshot([['foo' => 'bar']], 'foo');
+        $snapshot->getOriginalKey('baz');
+    }
+
+    public function testOriginalKey()
+    {
+        $snapshot = new CollectionSnapshot([['foo' => 'bar']], 'foo');
+
+        $this->assertSame(0, $snapshot->getOriginalKey('bar'));
+    }
 }