feat: add isEmpty and hasItems to collection

CHANGELOG.md

@@ -8,13 +8,15 @@ Added a couple of functions to the [Collection](./src/Domain/Collection.php) cla
 
 The following functions were added:
 * `fromIterable` - enables users of the collection to construction the collection from an iterable value like iterators, generators, etc.
-* `every` - Function that returns true if given callback returns truthy values for all items
-* `none` - Function that returns true if given callback returns falsy values for all items
-* `some` - Function that returns true if given callback returns truthy values on some items
+* `every` - Returns true if given callback returns truthy values for all items
+* `none` - Returns true if given callback returns falsy values for all items
+* `some` - Returns true if given callback returns truthy values on some items
 * `first` - Get the first element of the collection that matches a callback, if given. Throws exception if collection is empty or predicate is never satisfied
 * `firstOr` - Same as first but returns $fallbackValue if collection is empty or predicate is never satisfied
 * `last` - Get the last element of the collection that matches a callback, if given. Throws exception if collection is empty or predicate is never satisfied
 * `lastOr` - Same as last but returns $fallbackValue if collection is empty or predicate is never satisfied
+* `isEmpty` - Returns whether the collection is empty
+* `hasItems` - Returns whether the collection has items
 
 ## [1.4.0](https://github.com/geekcell/php-ddd/compare/v1.3.1...v1.4.0) (2023-12-19)
 

src/Domain/Collection.php

@@ -231,6 +231,22 @@ public function lastOr(callable $callback = null, mixed $fallbackValue = null)
         return $fallbackValue;
     }
 
+    /**
+     * Returns whether the collection is empty (has no items)
+     */
+    public function isEmpty(): bool
+    {
+        return $this->items === [];
+    }
+
+    /**
+     * Returns whether the collection has items
+     */
+    public function hasItems(): bool
+    {
+        return $this->items !== [];
+    }
+
     /**
      * Add one or more items to the collection. It **does not** modify the
      * current collection, but returns a new one.

tests/Domain/CollectionTest.php

@@ -526,4 +526,16 @@ public function testLastOrReturnsFallbackValueIfCallbackIsNeverSatisfied(): void
         $collection = new Collection($items);
         $this->assertSame(-1, $collection->lastOr(static fn ($item) => $item > 10, -1));
     }
+
+    public function testIsEmpty(): void
+    {
+        $this->assertFalse((new Collection([1]))->isEmpty());
+        $this->assertTrue((new Collection([]))->isEmpty());
+    }
+
+    public function testHasItems(): void
+    {
+        $this->assertFalse((new Collection([]))->hasItems());
+        $this->assertTrue((new Collection([1]))->hasItems());
+    }
 }