Implemented Collection::isEmpty()

src/Collection/CollectionInterface.php

@@ -830,4 +830,21 @@ public function unfold(callable $transformer = null);
      * @return \Cake\Collection\CollectionInterface
      */
     public function through(callable $handler);
+
+    /**
+     * Returns whether or not there are elements in this collection
+     *
+     * ### Example:
+     *
+     * ```
+     * $items [1, 2, 3];
+     * (new Collection($items))->isEmpty(); // false
+     * ```
+     * ```
+     * (new Collection([]))->isEmpty(); // true
+     * ```
+     *
+     * @return bool
+     */
+    public function isEmpty();
 }

src/Collection/CollectionTrait.php

@@ -531,6 +531,15 @@ public function through(callable $handler)
         return $result instanceof CollectionInterface ? $result: new Collection($result);
     }
 
+    /**
+     * {@inheritDoc}
+     *
+     */
+    public function isEmpty()
+    {
+        return iterator_count($this->take(1)) === 0;
+    }
+
     /**
      * Returns the closest nested iterator that can be safely traversed without
      * losing any possible transformations.

tests/TestCase/Collection/CollectionTest.php

@@ -1226,4 +1226,23 @@ public function testDebug()
         ];
         $this->assertSame($expected, $result);
     }
+
+    /**
+     * Tests the isEmpty() method
+     *
+     * @return void
+     */
+    public function testIsEmpty()
+    {
+        $collection = new Collection([1, 2, 3]);
+        $this->assertFalse($collection->isEmpty());
+
+        $collection = $collection->map(function () {
+            return null;
+        });
+        $this->assertFalse($collection->isEmpty());
+
+        $collection = $collection->filter();
+        $this->assertTrue($collection->isEmpty());
+    }
 }