Use value() helper in whenLoaded() (#24644)

src/Illuminate/Http/Resources/ConditionallyLoadsAttributes.php

@@ -141,7 +141,7 @@ protected function whenLoaded($relationship, $value = null, $default = null)
         }
 
         if (! $this->resource->relationLoaded($relationship)) {
-            return $default;
+            return value($default);
         }
 
         if (func_num_args() === 1) {

tests/Integration/Http/Fixtures/AuthorResourceWithOptionalRelationship.php

@@ -0,0 +1,21 @@
+<?php
+
+namespace Illuminate\Tests\Integration\Http\Fixtures;
+
+class AuthorResourceWithOptionalRelationship extends PostResource
+{
+    public function toArray($request)
+    {
+        return [
+            'name' => $this->name,
+            'posts_count' => $this->whenLoaded('posts', function () {
+                return $this->posts->count().' posts';
+            }, function () {
+                return 'not loaded';
+            }),
+            'latest_post_title' => $this->whenLoaded('posts', function () {
+                return optional($this->posts->first())->title ?: 'no posts yet';
+            }, 'not loaded'),
+        ];
+    }
+}

tests/Integration/Http/Fixtures/PostResourceWithOptionalData.php

@@ -15,6 +15,10 @@ public function toArray($request)
             'third' => $this->when(true, function () {
                 return 'value';
             }),
+            'fourth' => $this->when(false, 'value', 'default'),
+            'fifth' => $this->when(false, 'value', function () {
+                return 'default';
+            }),
         ];
     }
 }

tests/Integration/Http/ResourceTest.php

@@ -20,6 +20,7 @@
 use Illuminate\Tests\Integration\Http\Fixtures\PostResourceWithOptionalData;
 use Illuminate\Tests\Integration\Http\Fixtures\PostResourceWithOptionalMerging;
 use Illuminate\Tests\Integration\Http\Fixtures\PostResourceWithOptionalRelationship;
+use Illuminate\Tests\Integration\Http\Fixtures\AuthorResourceWithOptionalRelationship;
 use Illuminate\Tests\Integration\Http\Fixtures\PostResourceWithOptionalPivotRelationship;
 
 /**
@@ -88,6 +89,8 @@ public function test_resources_may_have_optional_values()
                 'id' => 5,
                 'second' => 'value',
                 'third' => 'value',
+                'fourth' => 'default',
+                'fifth' => 'default',
             ],
         ]);
     }
@@ -192,6 +195,29 @@ public function test_resources_may_shows_null_for_loaded_relationship_with_value
         ]);
     }
 
+    public function test_resources_may_have_optional_relationships_with_default_values()
+    {
+        Route::get('/', function () {
+            return new AuthorResourceWithOptionalRelationship(new Author([
+                'name' => 'jrrmartin',
+            ]));
+        });
+
+        $response = $this->withoutExceptionHandling()->get(
+            '/', ['Accept' => 'application/json']
+        );
+
+        $response->assertStatus(200);
+
+        $response->assertExactJson([
+            'data' => [
+                'name' => 'jrrmartin',
+                'posts_count' => 'not loaded',
+                'latest_post_title' => 'not loaded',
+            ],
+        ]);
+    }
+
     public function test_resources_may_have_optional_pivot_relationships()
     {
         Route::get('/', function () {