feat: add fromIterable function for Collection

Author: Bl00D4NGEL

src/Domain/Collection.php

@@ -5,6 +5,8 @@
 namespace GeekCell\Ddd\Domain;
 
 use Assert;
+use InvalidArgumentException;
+use Traversable;
 
 /**
  * @template T of object
@@ -26,11 +28,32 @@ final public function __construct(
         }
     }
 
+    /**
+     * Creates a collection from a given iterable of items.
+     * This function is useful when trying to create a collection from a generator or an iterator
+     *
+     * @param iterable<T> $items
+     * @param class-string<T>|null $itemType
+     * @return self<T>
+     */
+    public static function fromIterable(iterable $items, ?string $itemType = null): static
+    {
+        if (is_array($items)) {
+            return new static($items, $itemType);
+        }
+
+        if (!$items instanceof Traversable) {
+            $items = [...$items];
+        }
+
+        return new static(iterator_to_array($items), $itemType);
+    }
+
     /**
      * Add one or more items to the collection. It **does not** modify the
      * current collection, but returns a new one.
      *
-     * @param mixed $item One or more items to add to the collection.
+     * @param T|iterable<T> $item One or more items to add to the collection.
      * @return static
      */
     public function add(mixed $item): static
@@ -158,7 +181,7 @@ public function count(): int
     /**
      * @inheritDoc
      */
-    public function getIterator(): \Traversable
+    public function getIterator(): Traversable
     {
         return new \ArrayIterator($this->items);
     }

tests/Domain/CollectionTest.php

@@ -4,6 +4,7 @@
 
 namespace GeekCell\Ddd\Tests\Domain;
 
+use ArrayIterator;
 use Assert;
 use GeekCell\Ddd\Domain\Collection;
 use PHPUnit\Framework\TestCase;
@@ -300,4 +301,23 @@ public function testChaining(): void
         // Then
         $this->assertEquals(60, $result);
     }
+
+    public function testFromIterable(): void
+    {
+        $items = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
+        $collectionFromArray = Collection::fromIterable($items);
+        $this->assertSame($items, iterator_to_array($collectionFromArray));
+
+        $collectionFromIterator = Collection::fromIterable(new ArrayIterator($items));
+        $this->assertSame($items, iterator_to_array($collectionFromIterator));
+
+        $generatorFn = static function () use ($items) {
+            foreach ($items as $item) {
+                yield $item;
+            }
+        };
+
+        $collectionFromGenerator = Collection::fromIterable($generatorFn());
+        $this->assertSame($items, iterator_to_array($collectionFromGenerator));
+    }
 }