[9.x] Add unless to JsonResource

src/Illuminate/Http/Resources/ConditionallyLoadsAttributes.php

@@ -93,7 +93,7 @@ protected function removeMissingValues($data)
     }
 
     /**
-     * Retrieve a value based on a given condition.
+     * Retrieve a value if the given "condition" is truthy.
      *
      * @param  bool  $condition
      * @param  mixed  $value
@@ -109,6 +109,21 @@ protected function when($condition, $value, $default = null)
         return func_num_args() === 3 ? value($default) : new MissingValue;
     }
 
+    /**
+     * Retrieve a value if the given "condition" is falsy.
+     *
+     * @param  bool  $condition
+     * @param  mixed  $value
+     * @param  mixed  $default
+     * @return \Illuminate\Http\Resources\MissingValue|mixed
+     */
+    public function unless($condition, $value, $default = null)
+    {
+        $arguments = func_num_args() === 2 ? [$value] : [$value, $default];
+
+        return $this->when(! $condition, ...$arguments);
+    }
+
     /**
      * Merge a value into the array.
      *

tests/Integration/Http/Fixtures/PostResourceWithUnlessOptionalData.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace Illuminate\Tests\Integration\Http\Fixtures;
+
+use Illuminate\Http\Resources\Json\JsonResource;
+
+class PostResourceWithUnlessOptionalData extends JsonResource
+{
+    public function toArray($request)
+    {
+        return [
+            'id' => $this->id,
+            'first' => $this->unless(false, 'value'),
+            'second' => $this->unless(true, 'value'),
+            'third' => $this->unless(true, function () {
+                return 'value';
+            }),
+            'fourth' => $this->unless(false, 'value', 'default'),
+            'fifth' => $this->unless(false, 'value', function () {
+                return 'default';
+            }),
+        ];
+    }
+}

tests/Integration/Http/ResourceTest.php

@@ -37,6 +37,7 @@
 use Illuminate\Tests\Integration\Http\Fixtures\PostResourceWithOptionalRelationship;
 use Illuminate\Tests\Integration\Http\Fixtures\PostResourceWithOptionalRelationshipCounts;
 use Illuminate\Tests\Integration\Http\Fixtures\PostResourceWithoutWrap;
+use Illuminate\Tests\Integration\Http\Fixtures\PostResourceWithUnlessOptionalData;
 use Illuminate\Tests\Integration\Http\Fixtures\ReallyEmptyPostResource;
 use Illuminate\Tests\Integration\Http\Fixtures\ResourceWithPreservedKeys;
 use Illuminate\Tests\Integration\Http\Fixtures\SerializablePostResource;
@@ -167,6 +168,31 @@ public function testResourcesMayHaveOptionalValues()
         ]);
     }
 
+    public function testResourcesMayHaveOptionalValuesUsingUnless()
+    {
+        Route::get('/', function () {
+            return new PostResourceWithUnlessOptionalData(new Post([
+                'id' => 5,
+            ]));
+        });
+
+        $response = $this->withoutExceptionHandling()->get(
+            '/',
+            ['Accept' => 'application/json']
+        );
+
+        $response->assertStatus(200);
+
+        $response->assertJson([
+            'data' => [
+                'id' => 5,
+                'first' => 'value',
+                'fourth' => 'value',
+                'fifth' => 'value',
+            ],
+        ]);
+    }
+
     public function testResourcesMayHaveOptionalSelectedAttributes()
     {
         Route::get('/', function () {