feat(collectBy): support dot-notation (#247)

Author: innocenzi

src/Macros/CollectBy.php

@@ -2,6 +2,7 @@
 
 namespace Spatie\CollectionMacros\Macros;
 
+use Illuminate\Support\Arr;
 use Illuminate\Support\Collection;
 
 /**
@@ -19,7 +20,7 @@ class CollectBy
     public function __invoke()
     {
         return function ($key, $default = null): Collection {
-            return new static($this->get($key, $default));
+            return new static(Arr::get($this->items, $key, $default));
         };
     }
 }

tests/Macros/CollectByTest.php

@@ -60,3 +60,22 @@
 
     expect($ingredients)->toEqual(new Collection());
 });
+
+it('collects path from collection using dot notation', function () {
+    $collection = new Collection([
+        'baz.qux' => 'quux',
+        'foo' => [
+            'bar' => [
+                'baz' => 100,
+            ],
+        ],
+    ]);
+
+    expect($collection->collectBy('foo.bar'))->toBeInstanceOf(Collection::class);
+    expect($collection->collectBy('foo.bar')->toArray())->toEqual([
+        'baz' => 100,
+    ]);
+
+    expect($collection->collectBy('baz.qux'))->toBeInstanceOf(Collection::class);
+    expect($collection->collectBy('baz.qux')->toArray())->toEqual(['quux']);
+});