[5.x] Allow closure in cascade content hydration (#13580)

Author: marcorieser

src/View/Cascade.php

@@ -158,6 +158,10 @@ protected function hydrateContent()
             return $this;
         }
 
+        if ($this->content instanceof \Closure) {
+            $this->content = call_user_func($this->content);
+        }
+
         $variables = $this->content instanceof Augmentable
             ? $this->content->toDeferredAugmentedArray()
             : $this->content->toArray();

tests/View/CascadeTest.php

@@ -410,6 +410,32 @@ public function it_hydrates_page_data()
         });
     }
 
+    #[Test]
+    public function it_hydrates_page_data_by_closure()
+    {
+        $vars = ['foo' => 'bar', 'baz' => 'qux'];
+        $page = EntryFactory::id('test')
+            ->collection('example')
+            ->data($vars)
+            ->make();
+        $cascade = $this->cascade()->withContent(fn () => $page);
+
+        $this->assertEquals($page, call_user_func($cascade->content()));
+
+        tap($cascade->hydrate()->toArray(), function ($cascade) use ($page) {
+            $this->assertArrayHasKey('page', $cascade);
+            $this->assertEquals($page, $cascade['page']);
+
+            // The 'page' values should also be at the top level.
+            // They'll be Value classes so Antlers can lazily augment them.
+            // Blade can prefer {{ $globalhandle->field }} over just {{ $field }}
+            $this->assertEquals('bar', $cascade['foo']);
+            $this->assertEquals('qux', $cascade['baz']);
+            $this->assertInstanceOf(Value::class, $cascade['foo']);
+            $this->assertInstanceOf(Value::class, $cascade['baz']);
+        });
+    }
+
     #[Test]
     public function it_hydrates_globals()
     {