From 51fad48676ecd8adfe3c4a8225793b25409394f0 Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Fri, 28 Nov 2025 10:39:25 +0800
Subject: [PATCH 01/48] Filter empty `attributes` object

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 .../Resources/JsonApi/Concerns/ResolvesJsonApiElements.php | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
index 2b2a4ef4e5da..683f013c1c9e 100644
--- a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
+++ b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
@@ -112,6 +112,7 @@ protected function resolveResourceAttributes(JsonApiRequest $request, string $re
         $data = (new Collection($data))
             ->mapWithKeys(fn ($value, $key) => is_int($key) ? [$value => $this->resource->{$value}] : [$key => $value])
             ->when(! empty($sparseFieldset), fn ($attributes) => $attributes->only($sparseFieldset))
+            ->reject(fn ($value, $key) => $key === $this->resource->getKey())
             ->transform(fn ($value) => value($value, $request))
             ->all();
 
@@ -232,12 +233,12 @@ public function resolveIncludedResources(JsonApiRequest $request): array
 
             [$type, $id, $isUnique] = $value;
 
-            $relations->push([
+            $relations->push(array_filter([
                 'id' => $id,
                 'type' => $type,
                 '_uniqueKey' => $isUnique === true ? [$id, $type] : [$id, $type, (string) Str::random()],
-                'attributes' => Arr::get($resourceInstance->resolve($request), 'data.attributes', []),
-            ]);
+                'attributes' => Arr::get($resourceInstance->resolve($request), 'data.attributes'),
+            ]));
         }
 
         return $relations->uniqueStrict(fn ($relation) => $relation['_uniqueKey'])

From c62856b13267ba496bfe74016662bd3a057b80a6 Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Fri, 28 Nov 2025 17:49:02 +0800
Subject: [PATCH 02/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 .../Resources/JsonApi/Concerns/ResolvesJsonApiElements.php    | 4 ++--
 .../Http/Resources/JsonApi/JsonApiCollectionTest.php          | 3 ++-
 .../Http/Resources/JsonApi/JsonApiResourceTest.php            | 3 ++-
 3 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
index 683f013c1c9e..b49c298a29ea 100644
--- a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
+++ b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
@@ -199,14 +199,14 @@ protected function compileResourceRelationships(JsonApiRequest $request): void
                 return [$key => new MissingValue];
             }
 
-            return [$key => ['data' => [transform(
+            return [$key => ['data' => transform(
                 [static::resourceTypeFromModel($relatedModel), static::resourceIdFromModel($relatedModel)],
                 function ($uniqueKey) use ($relatedModel) {
                     $this->loadedRelationshipsMap[$relatedModel] = [...$uniqueKey, true];
 
                     return ['id' => $uniqueKey[1], 'type' => $uniqueKey[0]];
                 }
-            )]]];
+            )]];
         })->all();
     }
 
diff --git a/tests/Integration/Http/Resources/JsonApi/JsonApiCollectionTest.php b/tests/Integration/Http/Resources/JsonApi/JsonApiCollectionTest.php
index b295eddd36cb..f45ef5999d3d 100644
--- a/tests/Integration/Http/Resources/JsonApi/JsonApiCollectionTest.php
+++ b/tests/Integration/Http/Resources/JsonApi/JsonApiCollectionTest.php
@@ -122,7 +122,8 @@ public function testItCanGenerateJsonApiResponseWithRelationshipsUsingSparseIncl
                         'relationships' => [
                             'profile' => [
                                 'data' => [
-                                    ['id' => (string) $profile->getKey(), 'type' => 'profiles'],
+                                    'id' => (string) $profile->getKey(),
+                                    'type' => 'profiles',
                                 ],
                             ],
                             'posts' => [
diff --git a/tests/Integration/Http/Resources/JsonApi/JsonApiResourceTest.php b/tests/Integration/Http/Resources/JsonApi/JsonApiResourceTest.php
index fe166c5c10ba..1ba46b92810a 100644
--- a/tests/Integration/Http/Resources/JsonApi/JsonApiResourceTest.php
+++ b/tests/Integration/Http/Resources/JsonApi/JsonApiResourceTest.php
@@ -112,7 +112,8 @@ public function testItCanGenerateJsonApiResponseWithRelationshipsUsingSparseIncl
                         ],
                         'profile' => [
                             'data' => [
-                                ['id' => (string) $profile->getKey(), 'type' => 'profiles'],
+                                'id' => (string) $profile->getKey(),
+                                'type' => 'profiles',
                             ],
                         ],
                         'teams' => [

From 9964a2151439dd71bffed40063db2ab554f5a84b Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Fri, 28 Nov 2025 18:08:43 +0800
Subject: [PATCH 03/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 .../Resources/JsonApi/Concerns/ResolvesJsonApiElements.php | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
index b49c298a29ea..f27d8690bac8 100644
--- a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
+++ b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
@@ -233,11 +233,16 @@ public function resolveIncludedResources(JsonApiRequest $request): array
 
             [$type, $id, $isUnique] = $value;
 
+            $relationsData = $resourceInstance->resolve($request);
+
             $relations->push(array_filter([
                 'id' => $id,
                 'type' => $type,
                 '_uniqueKey' => $isUnique === true ? [$id, $type] : [$id, $type, (string) Str::random()],
-                'attributes' => Arr::get($resourceInstance->resolve($request), 'data.attributes'),
+                'attributes' => Arr::get($relationsData, 'data.attributes'),
+                'relationships' => Arr::get($relationsData, 'data.relationships'),
+                'links' => Arr::get($relationsData, 'data.links'),
+                'meta' => Arr::get($relationsData, 'data.meta'),
             ]));
         }
 

From 9f20af7b0e64f5158ddcc3248b101fabd57adc65 Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Fri, 28 Nov 2025 18:18:13 +0800
Subject: [PATCH 04/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 .../Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php | 2 +-
 .../Http/Resources/JsonApi/JsonApiCollectionTest.php            | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
index f27d8690bac8..9dd62c86e26a 100644
--- a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
+++ b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
@@ -137,7 +137,7 @@ protected function resolveResourceRelationshipIdentifiers(JsonApiRequest $reques
         return [
             ...(new Collection($this->filter($this->loadedRelationshipIdentifiers)))
                 ->map(function ($relation) {
-                    return ! is_null($relation) ? $relation : ['data' => []];
+                    return ! is_null($relation) ? $relation : ['data' => null];
                 })->all(),
         ];
     }
diff --git a/tests/Integration/Http/Resources/JsonApi/JsonApiCollectionTest.php b/tests/Integration/Http/Resources/JsonApi/JsonApiCollectionTest.php
index f45ef5999d3d..0726a1259a0a 100644
--- a/tests/Integration/Http/Resources/JsonApi/JsonApiCollectionTest.php
+++ b/tests/Integration/Http/Resources/JsonApi/JsonApiCollectionTest.php
@@ -107,7 +107,7 @@ public function testItCanGenerateJsonApiResponseWithRelationshipsUsingSparseIncl
                             'email' => $user->email,
                         ],
                         'relationships' => [
-                            'profile' => ['data' => []],
+                            'profile' => ['data' => null],
                             'posts' => ['data' => []],
                             'teams' => ['data' => []],
                         ],

From c09f42fc2c94d1a09ab2908e9c511aa09a6741a3 Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Fri, 28 Nov 2025 18:26:09 +0800
Subject: [PATCH 05/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 .../Resources/JsonApi/Concerns/ResolvesJsonApiElements.php    | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
index 9dd62c86e26a..8f490ffd52a4 100644
--- a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
+++ b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
@@ -154,7 +154,7 @@ protected function compileResourceRelationships(JsonApiRequest $request): void
         $sparseIncluded = $request->sparseIncluded();
 
         $resourceRelationships = (new Collection($this->toRelationships($request)))
-            ->mapWithKeys(fn ($value, $key) => is_int($key) ? [$value => fn () => $this->resource->{$value}] : [$key => $value])
+            ->mapWithKeys(fn ($value, $key) => is_int($key) ? [$value => fn ($resource) => $resource->getRelation($value)] : [$key => $value])
             ->filter(fn ($value, $key) => in_array($key, $sparseIncluded));
 
         $resourceRelationshipKeys = $resourceRelationships->keys();
@@ -164,7 +164,7 @@ protected function compileResourceRelationships(JsonApiRequest $request): void
         $this->loadedRelationshipsMap = new WeakMap;
 
         $this->loadedRelationshipIdentifiers = $resourceRelationships->mapWithKeys(function ($relationResolver, $key) {
-            $relatedModels = value($relationResolver);
+            $relatedModels = value($relationResolver, $this->resource);
 
             // Relationship is a collection of models...
             if ($relatedModels instanceof Collection) {

From f701acfdd14197d51c22504fcfb9e1ca768c203c Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Mon, 1 Dec 2025 09:29:43 +0800
Subject: [PATCH 06/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 .../Concerns/ResolvesJsonApiElements.php      |  7 +++---
 .../Resources/JsonApi/RelationResolver.php    | 22 +++++++++++++++++++
 2 files changed, 26 insertions(+), 3 deletions(-)
 create mode 100644 src/Illuminate/Http/Resources/JsonApi/RelationResolver.php

diff --git a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
index 8f490ffd52a4..828074d058a5 100644
--- a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
+++ b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
@@ -12,6 +12,7 @@
 use Illuminate\Http\Resources\JsonApi\Exceptions\ResourceIdentificationException;
 use Illuminate\Http\Resources\JsonApi\JsonApiRequest;
 use Illuminate\Http\Resources\JsonApi\JsonApiResource;
+use Illuminate\Http\Resources\RelationResolver;
 use Illuminate\Http\Resources\MissingValue;
 use Illuminate\Support\Arr;
 use Illuminate\Support\Collection;
@@ -154,7 +155,7 @@ protected function compileResourceRelationships(JsonApiRequest $request): void
         $sparseIncluded = $request->sparseIncluded();
 
         $resourceRelationships = (new Collection($this->toRelationships($request)))
-            ->mapWithKeys(fn ($value, $key) => is_int($key) ? [$value => fn ($resource) => $resource->getRelation($value)] : [$key => $value])
+            ->mapWithKeys(fn ($value, $key) => is_int($key) ? [$value => new RelationResolver($value)] : [$key => new RelationResolver($key, $value)])
             ->filter(fn ($value, $key) => in_array($key, $sparseIncluded));
 
         $resourceRelationshipKeys = $resourceRelationships->keys();
@@ -163,8 +164,8 @@ protected function compileResourceRelationships(JsonApiRequest $request): void
 
         $this->loadedRelationshipsMap = new WeakMap;
 
-        $this->loadedRelationshipIdentifiers = $resourceRelationships->mapWithKeys(function ($relationResolver, $key) {
-            $relatedModels = value($relationResolver, $this->resource);
+        $this->loadedRelationshipIdentifiers = $resourceRelationships->mapWithKeys(function (RelationResolver $relationResolver, $key) {
+            $relatedModels = $relationResolver->handle($this->resource);
 
             // Relationship is a collection of models...
             if ($relatedModels instanceof Collection) {
diff --git a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
new file mode 100644
index 000000000000..8514cd27b47b
--- /dev/null
+++ b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
@@ -0,0 +1,22 @@
+<?php
+
+namespace Illuminate\Http\Resources\JsonApi;
+
+use Illuminate\Database\Eloquent\Collection;
+use Illuminate\Database\Eloquent\Model;
+
+class RelationResolver
+{
+    public $relationResolver;
+
+    public function __construct(
+        public string $relationName,
+        Closure|string|null $resolver = null
+    ) {
+        $this->relationResolver = $resolver ?? fn ($resource) => $resource->getRelation($this->relationName);
+    }
+    public function handle(mixed $resource): Collection|Model
+    {
+        return value($this->relationResolver, $resource);
+    }
+}

From 0edfd1817fe07a604aee2db7db805b0ee83c9b3d Mon Sep 17 00:00:00 2001
From: StyleCI Bot <bot@styleci.io>
Date: Mon, 1 Dec 2025 01:30:07 +0000
Subject: [PATCH 07/48] Apply fixes from StyleCI

---
 .../Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php | 2 +-
 src/Illuminate/Http/Resources/JsonApi/RelationResolver.php      | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
index 828074d058a5..a9b2d50f6bb9 100644
--- a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
+++ b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
@@ -12,8 +12,8 @@
 use Illuminate\Http\Resources\JsonApi\Exceptions\ResourceIdentificationException;
 use Illuminate\Http\Resources\JsonApi\JsonApiRequest;
 use Illuminate\Http\Resources\JsonApi\JsonApiResource;
-use Illuminate\Http\Resources\RelationResolver;
 use Illuminate\Http\Resources\MissingValue;
+use Illuminate\Http\Resources\RelationResolver;
 use Illuminate\Support\Arr;
 use Illuminate\Support\Collection;
 use Illuminate\Support\Str;
diff --git a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
index 8514cd27b47b..0f6b3c11fe28 100644
--- a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
+++ b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
@@ -15,6 +15,7 @@ public function __construct(
     ) {
         $this->relationResolver = $resolver ?? fn ($resource) => $resource->getRelation($this->relationName);
     }
+
     public function handle(mixed $resource): Collection|Model
     {
         return value($this->relationResolver, $resource);

From fcc8e439ec2ce4468586a135a9c6e6e45392b819 Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Mon, 1 Dec 2025 10:27:08 +0800
Subject: [PATCH 08/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 .../Concerns/ResolvesJsonApiElements.php      | 28 +++++++++++++------
 .../Resources/JsonApi/RelationResolver.php    | 27 ++++++++++++++++--
 2 files changed, 44 insertions(+), 11 deletions(-)

diff --git a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
index a9b2d50f6bb9..78ac9b7f5992 100644
--- a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
+++ b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
@@ -12,8 +12,8 @@
 use Illuminate\Http\Resources\JsonApi\Exceptions\ResourceIdentificationException;
 use Illuminate\Http\Resources\JsonApi\JsonApiRequest;
 use Illuminate\Http\Resources\JsonApi\JsonApiResource;
+use Illuminate\Http\Resources\JsonApi\RelationResolver;
 use Illuminate\Http\Resources\MissingValue;
-use Illuminate\Http\Resources\RelationResolver;
 use Illuminate\Support\Arr;
 use Illuminate\Support\Collection;
 use Illuminate\Support\Str;
@@ -155,8 +155,11 @@ protected function compileResourceRelationships(JsonApiRequest $request): void
         $sparseIncluded = $request->sparseIncluded();
 
         $resourceRelationships = (new Collection($this->toRelationships($request)))
-            ->mapWithKeys(fn ($value, $key) => is_int($key) ? [$value => new RelationResolver($value)] : [$key => new RelationResolver($key, $value)])
-            ->filter(fn ($value, $key) => in_array($key, $sparseIncluded));
+            ->mapWithKeys(
+                fn ($value, $key) => is_int($key) ? [$value => new RelationResolver($value)] : [$key => new RelationResolver($key, $value)]
+            )->filter(
+                fn ($value, $key) => in_array($key, $sparseIncluded)
+            );
 
         $resourceRelationshipKeys = $resourceRelationships->keys();
 
@@ -166,6 +169,7 @@ protected function compileResourceRelationships(JsonApiRequest $request): void
 
         $this->loadedRelationshipIdentifiers = $resourceRelationships->mapWithKeys(function (RelationResolver $relationResolver, $key) {
             $relatedModels = $relationResolver->handle($this->resource);
+            $relatedResourceClass = $relationResolver->relationResourceClass;
 
             // Relationship is a collection of models...
             if ($relatedModels instanceof Collection) {
@@ -181,11 +185,15 @@ protected function compileResourceRelationships(JsonApiRequest $request): void
 
                 $key = static::resourceTypeFromModel($relatedModels->first());
 
-                return [$key => ['data' => $relatedModels->map(function ($relation) use ($key, $isUnique) {
-                    return transform([$key, static::resourceIdFromModel($relation)], function ($uniqueKey) use ($relation, $isUnique) {
+                return [$key => ['data' => $relatedModels->map(function ($relation) use ($key, $relatedResourceClass, $isUnique) {
+                    return transform([$key, static::resourceIdFromModel($relation)], function ($uniqueKey) use ($relation, $relatedResourceClass, $isUnique) {
                         $this->loadedRelationshipsMap[$relation] = [...$uniqueKey, $isUnique];
 
-                        return ['id' => $uniqueKey[1], 'type' => $uniqueKey[0]];
+                        return [
+                            'id' => $uniqueKey[1],
+                            'type' => $uniqueKey[0],
+                            'class' => $relatedResourceClass,
+                        ];
                     });
                 })]];
             }
@@ -202,10 +210,14 @@ protected function compileResourceRelationships(JsonApiRequest $request): void
 
             return [$key => ['data' => transform(
                 [static::resourceTypeFromModel($relatedModel), static::resourceIdFromModel($relatedModel)],
-                function ($uniqueKey) use ($relatedModel) {
+                function ($uniqueKey) use ($relatedModel, $relatedResourceClass) {
                     $this->loadedRelationshipsMap[$relatedModel] = [...$uniqueKey, true];
 
-                    return ['id' => $uniqueKey[1], 'type' => $uniqueKey[0]];
+                    return [
+                        'id' => $uniqueKey[1],
+                        'type' => $uniqueKey[0],
+                        'class' => $relatedResourceClass,
+                    ];
                 }
             )]];
         })->all();
diff --git a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
index 0f6b3c11fe28..ff78ffc33ad6 100644
--- a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
+++ b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
@@ -2,18 +2,39 @@
 
 namespace Illuminate\Http\Resources\JsonApi;
 
-use Illuminate\Database\Eloquent\Collection;
 use Illuminate\Database\Eloquent\Model;
+use Illuminate\Support\Collection;
 
 class RelationResolver
 {
-    public $relationResolver;
+    /**
+     * @var \Closure(mixed):(\Illuminate\Database\Eloquent\Collection|\Illuminate\Database\Eloquent\Model)
+     */
+    public Closure $relationResolver;
 
+    /**
+     * @var class-string<\Illuminate\Http\Resources\JsonApi\JsonApiResource>|null
+     */
+    public ?string $relationResourceClass;
+
+    /**
+     * Construct a new resource relationship resolver.
+     *
+     * @param string  $relationName
+     * @param \Closure(mixed):(\Illuminate\Database\Eloquent\Collection|\Illuminate\Database\Eloquent\Model)|class-string<\Illuminate\Http\Resources\JsonApi\JsonApiResource>|null   $resolver
+     */
     public function __construct(
         public string $relationName,
         Closure|string|null $resolver = null
     ) {
-        $this->relationResolver = $resolver ?? fn ($resource) => $resource->getRelation($this->relationName);
+        $this->relationResolver = match (true) {
+            $resolver instanceof Closure => $resolver,
+            default => fn ($resource) => $resource->getRelation($this->relationName),
+        };
+
+        if (is_string($resolver) && class_exists($resolver)) {
+            $this->relationResourceClass = $resolver;
+        }
     }
 
     public function handle(mixed $resource): Collection|Model

From af659e8d389ca667041a14c173994324a5545a55 Mon Sep 17 00:00:00 2001
From: StyleCI Bot <bot@styleci.io>
Date: Mon, 1 Dec 2025 02:27:22 +0000
Subject: [PATCH 09/48] Apply fixes from StyleCI

---
 src/Illuminate/Http/Resources/JsonApi/RelationResolver.php | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
index ff78ffc33ad6..3aac5dca1ebf 100644
--- a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
+++ b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
@@ -20,8 +20,8 @@ class RelationResolver
     /**
      * Construct a new resource relationship resolver.
      *
-     * @param string  $relationName
-     * @param \Closure(mixed):(\Illuminate\Database\Eloquent\Collection|\Illuminate\Database\Eloquent\Model)|class-string<\Illuminate\Http\Resources\JsonApi\JsonApiResource>|null   $resolver
+     * @param  string  $relationName
+     * @param  \Closure(mixed):(\Illuminate\Database\Eloquent\Collection|\Illuminate\Database\Eloquent\Model)|class-string<\Illuminate\Http\Resources\JsonApi\JsonApiResource>|null  $resolver
      */
     public function __construct(
         public string $relationName,

From 54d579b6618651185b9e6efbcdde5460ddbb090c Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Mon, 1 Dec 2025 10:49:34 +0800
Subject: [PATCH 10/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 .../JsonApi/Concerns/ResolvesJsonApiElements.php     | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
index 78ac9b7f5992..e1f278723945 100644
--- a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
+++ b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
@@ -187,12 +187,11 @@ protected function compileResourceRelationships(JsonApiRequest $request): void
 
                 return [$key => ['data' => $relatedModels->map(function ($relation) use ($key, $relatedResourceClass, $isUnique) {
                     return transform([$key, static::resourceIdFromModel($relation)], function ($uniqueKey) use ($relation, $relatedResourceClass, $isUnique) {
-                        $this->loadedRelationshipsMap[$relation] = [...$uniqueKey, $isUnique];
+                        $this->loadedRelationshipsMap[$relation] = [...$uniqueKey, $relatedResourceClass, $isUnique];
 
                         return [
                             'id' => $uniqueKey[1],
                             'type' => $uniqueKey[0],
-                            'class' => $relatedResourceClass,
                         ];
                     });
                 })]];
@@ -211,12 +210,11 @@ protected function compileResourceRelationships(JsonApiRequest $request): void
             return [$key => ['data' => transform(
                 [static::resourceTypeFromModel($relatedModel), static::resourceIdFromModel($relatedModel)],
                 function ($uniqueKey) use ($relatedModel, $relatedResourceClass) {
-                    $this->loadedRelationshipsMap[$relatedModel] = [...$uniqueKey, true];
+                    $this->loadedRelationshipsMap[$relatedModel] = [...$uniqueKey, $relatedResourceClass, true];
 
                     return [
                         'id' => $uniqueKey[1],
                         'type' => $uniqueKey[0],
-                        'class' => $relatedResourceClass,
                     ];
                 }
             )]];
@@ -237,15 +235,15 @@ public function resolveIncludedResources(JsonApiRequest $request): array
         $relations = new Collection;
 
         foreach ($this->loadedRelationshipsMap as $relation => $value) {
-            $resourceInstance = rescue(fn () => $relation->toResource(), new JsonApiResource($relation), false);
+            [$type, $id, $relatedResourceClass, $isUnique] = $value;
+
+            $resourceInstance = rescue(fn () => $relation->toResource($relatedResourceClass), new JsonApiResource($relation), false);
 
             if (! $resourceInstance instanceof JsonApiResource &&
                 $resourceInstance instanceof JsonResource) {
                 $resourceInstance = new JsonApiResource($resourceInstance->resource);
             }
 
-            [$type, $id, $isUnique] = $value;
-
             $relationsData = $resourceInstance->resolve($request);
 
             $relations->push(array_filter([

From a524678389572676b63b926e072656c94ee2f0bd Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Mon, 1 Dec 2025 10:59:22 +0800
Subject: [PATCH 11/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 src/Illuminate/Http/Resources/JsonApi/RelationResolver.php | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
index 3aac5dca1ebf..ce0a38239a82 100644
--- a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
+++ b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
@@ -2,8 +2,9 @@
 
 namespace Illuminate\Http\Resources\JsonApi;
 
+use Closure;
+use Illuminate\Database\Eloquent\Collection;
 use Illuminate\Database\Eloquent\Model;
-use Illuminate\Support\Collection;
 
 class RelationResolver
 {

From 84a230c486d89a9ef30dbbed657bb5ee88a419bb Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Mon, 1 Dec 2025 11:00:19 +0800
Subject: [PATCH 12/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 src/Illuminate/Http/Resources/JsonApi/RelationResolver.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
index ce0a38239a82..3377a0a08cce 100644
--- a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
+++ b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
@@ -16,7 +16,7 @@ class RelationResolver
     /**
      * @var class-string<\Illuminate\Http\Resources\JsonApi\JsonApiResource>|null
      */
-    public ?string $relationResourceClass;
+    public ?string $relationResourceClass = null;
 
     /**
      * Construct a new resource relationship resolver.

From c7c265f90cef038040145bf1d10b1917ff7a1a95 Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Mon, 1 Dec 2025 11:02:05 +0800
Subject: [PATCH 13/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 src/Illuminate/Http/Resources/JsonApi/RelationResolver.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
index 3377a0a08cce..aa777fdbef7c 100644
--- a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
+++ b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
@@ -38,7 +38,7 @@ public function __construct(
         }
     }
 
-    public function handle(mixed $resource): Collection|Model
+    public function handle(mixed $resource): Collection|Model|null
     {
         return value($this->relationResolver, $resource);
     }

From 496ce0b1be72fc3fe99d4530c3b7f32de483530b Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Mon, 1 Dec 2025 11:04:45 +0800
Subject: [PATCH 14/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 src/Illuminate/Http/Resources/JsonApi/RelationResolver.php | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
index aa777fdbef7c..2f6270675e56 100644
--- a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
+++ b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
@@ -6,6 +6,9 @@
 use Illuminate\Database\Eloquent\Collection;
 use Illuminate\Database\Eloquent\Model;
 
+/**
+ * @internal
+ */
 class RelationResolver
 {
     /**
@@ -21,7 +24,6 @@ class RelationResolver
     /**
      * Construct a new resource relationship resolver.
      *
-     * @param  string  $relationName
      * @param  \Closure(mixed):(\Illuminate\Database\Eloquent\Collection|\Illuminate\Database\Eloquent\Model)|class-string<\Illuminate\Http\Resources\JsonApi\JsonApiResource>|null  $resolver
      */
     public function __construct(
@@ -38,6 +40,9 @@ public function __construct(
         }
     }
 
+    /**
+     * Resolve relation for a resource.
+     */
     public function handle(mixed $resource): Collection|Model|null
     {
         return value($this->relationResolver, $resource);

From 46ee3b9a5a4a04437bbe1a3465d7f1bca4cd10c7 Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Mon, 1 Dec 2025 12:08:46 +0800
Subject: [PATCH 15/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 src/Illuminate/Http/Resources/JsonApi/RelationResolver.php | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
index 2f6270675e56..2288aa69c01e 100644
--- a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
+++ b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
@@ -12,7 +12,7 @@
 class RelationResolver
 {
     /**
-     * @var \Closure(mixed):(\Illuminate\Database\Eloquent\Collection|\Illuminate\Database\Eloquent\Model)
+     * @var \Closure(mixed):(\Illuminate\Database\Eloquent\Collection|\Illuminate\Database\Eloquent\Model|null)
      */
     public Closure $relationResolver;
 
@@ -24,7 +24,7 @@ class RelationResolver
     /**
      * Construct a new resource relationship resolver.
      *
-     * @param  \Closure(mixed):(\Illuminate\Database\Eloquent\Collection|\Illuminate\Database\Eloquent\Model)|class-string<\Illuminate\Http\Resources\JsonApi\JsonApiResource>|null  $resolver
+     * @param  \Closure(mixed):(\Illuminate\Database\Eloquent\Collection|\Illuminate\Database\Eloquent\Model|null)|class-string<\Illuminate\Http\Resources\JsonApi\JsonApiResource>|null  $resolver
      */
     public function __construct(
         public string $relationName,

From e4be683058d10023f716a7d88241de55afbebd43 Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Mon, 1 Dec 2025 12:34:58 +0800
Subject: [PATCH 16/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 .../JsonApi/Fixtures/AuthorApiResource.php    | 21 +++++++++++++++++++
 .../Http/Resources/JsonApi/Fixtures/Post.php  |  2 +-
 .../JsonApi/Fixtures/PostApiResource.php      |  4 ++++
 3 files changed, 26 insertions(+), 1 deletion(-)
 create mode 100644 tests/Integration/Http/Resources/JsonApi/Fixtures/AuthorApiResource.php

diff --git a/tests/Integration/Http/Resources/JsonApi/Fixtures/AuthorApiResource.php b/tests/Integration/Http/Resources/JsonApi/Fixtures/AuthorApiResource.php
new file mode 100644
index 000000000000..1ce39362b057
--- /dev/null
+++ b/tests/Integration/Http/Resources/JsonApi/Fixtures/AuthorApiResource.php
@@ -0,0 +1,21 @@
+<?php
+
+namespace Illuminate\Tests\Integration\Http\Resources\JsonApi\Fixtures;
+
+use Illuminate\Http\Request;
+use Illuminate\Http\Resources\JsonApi\JsonApiResource;
+
+class AuthorApiResource extends JsonApiResource
+{
+    protected array $relationships = [
+        'profile',
+    ];
+
+    public function toAttributes(Request $request)
+    {
+        return [
+            'name' => $this->name,
+            'email' => $this->email,
+        ];
+    }
+}
diff --git a/tests/Integration/Http/Resources/JsonApi/Fixtures/Post.php b/tests/Integration/Http/Resources/JsonApi/Fixtures/Post.php
index 143758e2c966..3f035bbd3c5f 100644
--- a/tests/Integration/Http/Resources/JsonApi/Fixtures/Post.php
+++ b/tests/Integration/Http/Resources/JsonApi/Fixtures/Post.php
@@ -13,7 +13,7 @@ class Post extends Model
 {
     use HasFactory;
 
-    public function user()
+    public function author()
     {
         return $this->belongsTo(User::class);
     }
diff --git a/tests/Integration/Http/Resources/JsonApi/Fixtures/PostApiResource.php b/tests/Integration/Http/Resources/JsonApi/Fixtures/PostApiResource.php
index 6309e6cc5c91..dd847d304c5b 100644
--- a/tests/Integration/Http/Resources/JsonApi/Fixtures/PostApiResource.php
+++ b/tests/Integration/Http/Resources/JsonApi/Fixtures/PostApiResource.php
@@ -10,4 +10,8 @@ class PostApiResource extends JsonApiResource
         'title',
         'content',
     ];
+
+    protected array $relationships = [
+        'author' => AuthorApiResource::class,
+    ];
 }

From e28661c2cba114faacc1bf6e37eb1ec6910a9798 Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Mon, 1 Dec 2025 12:40:01 +0800
Subject: [PATCH 17/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 .../Http/Resources/JsonApi/Fixtures/AuthorApiResource.php  | 7 +++++++
 .../Http/Resources/JsonApi/Fixtures/UserApiResource.php    | 1 +
 .../Http/Resources/JsonApi/Fixtures/UserResource.php       | 1 +
 3 files changed, 9 insertions(+)

diff --git a/tests/Integration/Http/Resources/JsonApi/Fixtures/AuthorApiResource.php b/tests/Integration/Http/Resources/JsonApi/Fixtures/AuthorApiResource.php
index 1ce39362b057..0f8f7403cedc 100644
--- a/tests/Integration/Http/Resources/JsonApi/Fixtures/AuthorApiResource.php
+++ b/tests/Integration/Http/Resources/JsonApi/Fixtures/AuthorApiResource.php
@@ -11,6 +11,7 @@ class AuthorApiResource extends JsonApiResource
         'profile',
     ];
 
+    #[\Override]
     public function toAttributes(Request $request)
     {
         return [
@@ -18,4 +19,10 @@ public function toAttributes(Request $request)
             'email' => $this->email,
         ];
     }
+
+    #[\Override]
+    public function toType(Request $request)
+    {
+        return 'authors';
+    }
 }
diff --git a/tests/Integration/Http/Resources/JsonApi/Fixtures/UserApiResource.php b/tests/Integration/Http/Resources/JsonApi/Fixtures/UserApiResource.php
index 7d1a7c7918c5..a45a8b37fa78 100644
--- a/tests/Integration/Http/Resources/JsonApi/Fixtures/UserApiResource.php
+++ b/tests/Integration/Http/Resources/JsonApi/Fixtures/UserApiResource.php
@@ -13,6 +13,7 @@ class UserApiResource extends JsonApiResource
         'teams',
     ];
 
+    #[\Override]
     public function toAttributes(Request $request)
     {
         return [
diff --git a/tests/Integration/Http/Resources/JsonApi/Fixtures/UserResource.php b/tests/Integration/Http/Resources/JsonApi/Fixtures/UserResource.php
index 7ddd2248a37b..05b5e843fccd 100644
--- a/tests/Integration/Http/Resources/JsonApi/Fixtures/UserResource.php
+++ b/tests/Integration/Http/Resources/JsonApi/Fixtures/UserResource.php
@@ -7,6 +7,7 @@
 
 class UserResource extends JsonResource
 {
+    #[\Override]
     public function toArray(Request $request)
     {
         return [

From 302b3b12adb83fb9d65426caa195b04a7cf420ff Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Tue, 2 Dec 2025 09:32:25 +0800
Subject: [PATCH 18/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 .../Concerns/ResolvesJsonApiElements.php      | 13 ++++++------
 .../Resources/JsonApi/RelationResolver.php    | 21 +++++++++++++++++++
 2 files changed, 28 insertions(+), 6 deletions(-)

diff --git a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
index e1f278723945..0b34cbb19034 100644
--- a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
+++ b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
@@ -167,9 +167,10 @@ protected function compileResourceRelationships(JsonApiRequest $request): void
 
         $this->loadedRelationshipsMap = new WeakMap;
 
-        $this->loadedRelationshipIdentifiers = $resourceRelationships->mapWithKeys(function (RelationResolver $relationResolver, $key) {
+        $this->loadedRelationshipIdentifiers = $resourceRelationships->mapWithKeys(function (RelationResolver $relationResolver, $key) use ($request) {
             $relatedModels = $relationResolver->handle($this->resource);
-            $relatedResourceClass = $relationResolver->relationResourceClass;
+            $relatedResourceType = $relationResolver->resourceType($relatedModels, $request);
+            $relatedResourceClass = $relationResolver->resourceClass();
 
             // Relationship is a collection of models...
             if ($relatedModels instanceof Collection) {
@@ -183,7 +184,7 @@ protected function compileResourceRelationships(JsonApiRequest $request): void
 
                 $isUnique = ! $relationship instanceof BelongsToMany;
 
-                $key = static::resourceTypeFromModel($relatedModels->first());
+                $key = $relatedResourceType ?? static::resourceTypeFromModel($relatedModels->first());
 
                 return [$key => ['data' => $relatedModels->map(function ($relation) use ($key, $relatedResourceClass, $isUnique) {
                     return transform([$key, static::resourceIdFromModel($relation)], function ($uniqueKey) use ($relation, $relatedResourceClass, $isUnique) {
@@ -208,7 +209,7 @@ protected function compileResourceRelationships(JsonApiRequest $request): void
             }
 
             return [$key => ['data' => transform(
-                [static::resourceTypeFromModel($relatedModel), static::resourceIdFromModel($relatedModel)],
+                [$relatedResourceType ?? static::resourceTypeFromModel($relatedModel), static::resourceIdFromModel($relatedModel)],
                 function ($uniqueKey) use ($relatedModel, $relatedResourceClass) {
                     $this->loadedRelationshipsMap[$relatedModel] = [...$uniqueKey, $relatedResourceClass, true];
 
@@ -285,7 +286,7 @@ protected function resolveResourceMetaInformation(JsonApiRequest $request): arra
     /**
      * Get the resource ID from the given Eloquent model.
      */
-    protected static function resourceIdFromModel(Model $model): string
+    public static function resourceIdFromModel(Model $model): string
     {
         return $model->getKey();
     }
@@ -293,7 +294,7 @@ protected static function resourceIdFromModel(Model $model): string
     /**
      * Get the resource type from the given Eloquent model.
      */
-    protected static function resourceTypeFromModel(Model $model): string
+    public static function resourceTypeFromModel(Model $model): string
     {
         $modelClassName = $model::class;
 
diff --git a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
index 2288aa69c01e..9c20dae58122 100644
--- a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
+++ b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
@@ -47,4 +47,25 @@ public function handle(mixed $resource): Collection|Model|null
     {
         return value($this->relationResolver, $resource);
     }
+
+    /**
+     * Get the resource class.
+     *
+     * @return class-string<\Illuminate\Http\Resources\JsonApi\JsonApiResource>|null
+     */
+    public function resourceClass(): ?string
+    {
+        return $this->relationResourceClass;
+    }
+
+    public function resourceType(Collection|Model|null $resources, JsonApiRequest $request): ?string
+    {
+        if (is_null($resourceClass = $this->resourceClass())) {
+            return null;
+        }
+
+        $resource = $resources instanceof Collection ? $resources->first() : $resources;
+
+        return (new $resourceClass($resource))->toType($request);
+    }
 }

From 92e5d4dd51d54144f03d1d39cbe46e2748452a1f Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Tue, 2 Dec 2025 09:43:27 +0800
Subject: [PATCH 19/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 .../JsonApi/Concerns/ResolvesJsonApiElements.php          | 5 ++---
 .../Http/Resources/JsonApi/RelationResolver.php           | 8 +++++---
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
index 0b34cbb19034..5d82d38c1656 100644
--- a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
+++ b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
@@ -169,7 +169,6 @@ protected function compileResourceRelationships(JsonApiRequest $request): void
 
         $this->loadedRelationshipIdentifiers = $resourceRelationships->mapWithKeys(function (RelationResolver $relationResolver, $key) use ($request) {
             $relatedModels = $relationResolver->handle($this->resource);
-            $relatedResourceType = $relationResolver->resourceType($relatedModels, $request);
             $relatedResourceClass = $relationResolver->resourceClass();
 
             // Relationship is a collection of models...
@@ -184,7 +183,7 @@ protected function compileResourceRelationships(JsonApiRequest $request): void
 
                 $isUnique = ! $relationship instanceof BelongsToMany;
 
-                $key = $relatedResourceType ?? static::resourceTypeFromModel($relatedModels->first());
+                $key = $relationResolver->resourceType($relatedModels, $request);
 
                 return [$key => ['data' => $relatedModels->map(function ($relation) use ($key, $relatedResourceClass, $isUnique) {
                     return transform([$key, static::resourceIdFromModel($relation)], function ($uniqueKey) use ($relation, $relatedResourceClass, $isUnique) {
@@ -209,7 +208,7 @@ protected function compileResourceRelationships(JsonApiRequest $request): void
             }
 
             return [$key => ['data' => transform(
-                [$relatedResourceType ?? static::resourceTypeFromModel($relatedModel), static::resourceIdFromModel($relatedModel)],
+                [$relationResolver->resourceType($relatedModel, $request), static::resourceIdFromModel($relatedModel)],
                 function ($uniqueKey) use ($relatedModel, $relatedResourceClass) {
                     $this->loadedRelationshipsMap[$relatedModel] = [...$uniqueKey, $relatedResourceClass, true];
 
diff --git a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
index 9c20dae58122..c3f67668188f 100644
--- a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
+++ b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
@@ -60,12 +60,14 @@ public function resourceClass(): ?string
 
     public function resourceType(Collection|Model|null $resources, JsonApiRequest $request): ?string
     {
-        if (is_null($resourceClass = $this->resourceClass())) {
+        $resource = $resources instanceof Collection ? $resources->first() : $resources;
+
+        if (is_null($resource)) {
             return null;
+        } elseif (is_null($resourceClass = $this->resourceClass())) {
+            return JsonApiResource::resourceTypeFromModel($resource);
         }
 
-        $resource = $resources instanceof Collection ? $resources->first() : $resources;
-
         return (new $resourceClass($resource))->toType($request);
     }
 }

From 7f0b513ebd65a95b184ac27108997f4c3a857e6e Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Tue, 2 Dec 2025 09:48:20 +0800
Subject: [PATCH 20/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 tests/Integration/Http/Resources/JsonApi/Fixtures/Post.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/Integration/Http/Resources/JsonApi/Fixtures/Post.php b/tests/Integration/Http/Resources/JsonApi/Fixtures/Post.php
index 3f035bbd3c5f..ee4129099a68 100644
--- a/tests/Integration/Http/Resources/JsonApi/Fixtures/Post.php
+++ b/tests/Integration/Http/Resources/JsonApi/Fixtures/Post.php
@@ -15,6 +15,6 @@ class Post extends Model
 
     public function author()
     {
-        return $this->belongsTo(User::class);
+        return $this->belongsTo(User::class, 'user_id');
     }
 }

From 7af5ced11cf6bc2fa9877a4fb33398a6094a9e82 Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Tue, 2 Dec 2025 09:52:52 +0800
Subject: [PATCH 21/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 src/Illuminate/Http/Resources/JsonApi/RelationResolver.php | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
index c3f67668188f..88a23dd04d27 100644
--- a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
+++ b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
@@ -58,6 +58,9 @@ public function resourceClass(): ?string
         return $this->relationResourceClass;
     }
 
+    /**
+     * Get the relation resource type.
+     */
     public function resourceType(Collection|Model|null $resources, JsonApiRequest $request): ?string
     {
         $resource = $resources instanceof Collection ? $resources->first() : $resources;

From 29d6aa21919baa312a79504b86dfd8d5dca065e7 Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Tue, 2 Dec 2025 10:04:06 +0800
Subject: [PATCH 22/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 src/Illuminate/Http/Resources/JsonApi/RelationResolver.php | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
index 88a23dd04d27..61be9d9bf646 100644
--- a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
+++ b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
@@ -61,13 +61,11 @@ public function resourceClass(): ?string
     /**
      * Get the relation resource type.
      */
-    public function resourceType(Collection|Model|null $resources, JsonApiRequest $request): ?string
+    public function resourceType(Collection|Model $resources, JsonApiRequest $request): ?string
     {
         $resource = $resources instanceof Collection ? $resources->first() : $resources;
 
-        if (is_null($resource)) {
-            return null;
-        } elseif (is_null($resourceClass = $this->resourceClass())) {
+        if (is_null($resourceClass = $this->resourceClass())) {
             return JsonApiResource::resourceTypeFromModel($resource);
         }
 

From 15f56cd64ff0472731f80ea88b4cd21aea957248 Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Tue, 2 Dec 2025 13:51:38 +0800
Subject: [PATCH 23/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 src/Illuminate/Http/Resources/JsonApi/RelationResolver.php | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
index 61be9d9bf646..098d20ef6a6c 100644
--- a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
+++ b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
@@ -12,11 +12,15 @@
 class RelationResolver
 {
     /**
+     * The relation resolver.
+     *
      * @var \Closure(mixed):(\Illuminate\Database\Eloquent\Collection|\Illuminate\Database\Eloquent\Model|null)
      */
     public Closure $relationResolver;
 
     /**
+     * The relation resource class.
+     *
      * @var class-string<\Illuminate\Http\Resources\JsonApi\JsonApiResource>|null
      */
     public ?string $relationResourceClass = null;

From b33b40b65164d0f9d72900b0c93d4549d54d128b Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Tue, 2 Dec 2025 16:36:06 +0800
Subject: [PATCH 24/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 .../Http/Resources/JsonApi/RelationResolver.php        | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
index 098d20ef6a6c..9837f8292ed2 100644
--- a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
+++ b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
@@ -5,6 +5,7 @@
 use Closure;
 use Illuminate\Database\Eloquent\Collection;
 use Illuminate\Database\Eloquent\Model;
+use Illuminate\Http\Resources\JsonApi\Exceptions\ResourceIdentificationException;
 
 /**
  * @internal
@@ -73,6 +74,13 @@ public function resourceType(Collection|Model $resources, JsonApiRequest $reques
             return JsonApiResource::resourceTypeFromModel($resource);
         }
 
-        return (new $resourceClass($resource))->toType($request);
+        $relatedResource = new $resourceClass($resource);
+
+        return tap($relatedResource->toType($request), function ($resourceType) use ($relatedResource) {
+            throw_if(
+                is_null($resourceType),
+                ResourceIdentificationException::attemptingToDetermineTypeFor($relatedResource)
+            );
+        });
     }
 }

From 6f528759f2400d547c0d8427887ee67931489946 Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Tue, 2 Dec 2025 20:15:09 +0800
Subject: [PATCH 25/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 .../JsonApi/Fixtures/AuthorApiResource.php    |  1 +
 .../Resources/JsonApi/Fixtures/Comment.php    | 23 ++++++++
 .../JsonApi/Fixtures/CommentApiResource.php   | 24 ++++++++
 .../JsonApi/Fixtures/CommentFactory.php       | 18 ++++++
 .../Http/Resources/JsonApi/Fixtures/Post.php  |  5 ++
 .../Http/Resources/JsonApi/Fixtures/User.php  |  5 ++
 .../JsonApi/Fixtures/UserApiResource.php      |  1 +
 .../Resources/JsonApi/Fixtures/migrations.php |  8 +++
 .../Resources/JsonApi/JsonApiResourceTest.php | 55 +++++++++++++++++++
 .../Http/Resources/JsonApi/TestCase.php       |  9 +++
 10 files changed, 149 insertions(+)
 create mode 100644 tests/Integration/Http/Resources/JsonApi/Fixtures/Comment.php
 create mode 100644 tests/Integration/Http/Resources/JsonApi/Fixtures/CommentApiResource.php
 create mode 100644 tests/Integration/Http/Resources/JsonApi/Fixtures/CommentFactory.php

diff --git a/tests/Integration/Http/Resources/JsonApi/Fixtures/AuthorApiResource.php b/tests/Integration/Http/Resources/JsonApi/Fixtures/AuthorApiResource.php
index 0f8f7403cedc..227723bbc1b2 100644
--- a/tests/Integration/Http/Resources/JsonApi/Fixtures/AuthorApiResource.php
+++ b/tests/Integration/Http/Resources/JsonApi/Fixtures/AuthorApiResource.php
@@ -8,6 +8,7 @@
 class AuthorApiResource extends JsonApiResource
 {
     protected array $relationships = [
+        'comments',
         'profile',
     ];
 
diff --git a/tests/Integration/Http/Resources/JsonApi/Fixtures/Comment.php b/tests/Integration/Http/Resources/JsonApi/Fixtures/Comment.php
new file mode 100644
index 000000000000..05a516624d4b
--- /dev/null
+++ b/tests/Integration/Http/Resources/JsonApi/Fixtures/Comment.php
@@ -0,0 +1,23 @@
+<?php
+
+namespace Illuminate\Tests\Integration\Http\Resources\JsonApi\Fixtures;
+
+use Illuminate\Database\Eloquent\Attributes\UseFactory;
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+
+#[UseFactory(CommentFactory::class)]
+class Comment extends Model
+{
+    use HasFactory;
+
+    public function post()
+    {
+        return $this->belongsTo(Post::class);
+    }
+
+    public function commenter()
+    {
+        return $this->belongsTo(User::class, 'user_id');
+    }
+}
diff --git a/tests/Integration/Http/Resources/JsonApi/Fixtures/CommentApiResource.php b/tests/Integration/Http/Resources/JsonApi/Fixtures/CommentApiResource.php
new file mode 100644
index 000000000000..8302d235113e
--- /dev/null
+++ b/tests/Integration/Http/Resources/JsonApi/Fixtures/CommentApiResource.php
@@ -0,0 +1,24 @@
+<?php
+
+namespace Illuminate\Tests\Integration\Http\Resources\JsonApi\Fixtures;
+
+use Illuminate\Http\Request;
+use Illuminate\Http\Resources\JsonApi\JsonApiResource;
+
+class CommentApiResource extends JsonApiResource
+{
+    /**
+     * The resource's attributes.
+     */
+    public $attributes = [
+        'content',
+    ];
+
+    /**
+     * The resource's relationships.
+     */
+    public $relationships = [
+        'posts',
+        'commenter' => UserApiResource::class,
+    ];
+}
diff --git a/tests/Integration/Http/Resources/JsonApi/Fixtures/CommentFactory.php b/tests/Integration/Http/Resources/JsonApi/Fixtures/CommentFactory.php
new file mode 100644
index 000000000000..3d6c26308cf7
--- /dev/null
+++ b/tests/Integration/Http/Resources/JsonApi/Fixtures/CommentFactory.php
@@ -0,0 +1,18 @@
+<?php
+
+namespace Illuminate\Tests\Integration\Http\Resources\JsonApi\Fixtures;
+
+use Illuminate\Database\Eloquent\Factories\Factory;
+use Orchestra\Testbench\Factories\UserFactory;
+
+class CommentFactory extends Factory
+{
+    public function definition(): array
+    {
+        return [
+            'post_id' => PostFactory::new(),
+            'user_id' => UserFactory::new(),
+            'content' => $this->faker->words(10, true),
+        ];
+    }
+}
diff --git a/tests/Integration/Http/Resources/JsonApi/Fixtures/Post.php b/tests/Integration/Http/Resources/JsonApi/Fixtures/Post.php
index ee4129099a68..1c583b9ce9cb 100644
--- a/tests/Integration/Http/Resources/JsonApi/Fixtures/Post.php
+++ b/tests/Integration/Http/Resources/JsonApi/Fixtures/Post.php
@@ -13,6 +13,11 @@ class Post extends Model
 {
     use HasFactory;
 
+    public function comments()
+    {
+        return $this->hasMany(Comment::class);
+    }
+
     public function author()
     {
         return $this->belongsTo(User::class, 'user_id');
diff --git a/tests/Integration/Http/Resources/JsonApi/Fixtures/User.php b/tests/Integration/Http/Resources/JsonApi/Fixtures/User.php
index ef7cac2097a2..a7adc43ba121 100644
--- a/tests/Integration/Http/Resources/JsonApi/Fixtures/User.php
+++ b/tests/Integration/Http/Resources/JsonApi/Fixtures/User.php
@@ -24,6 +24,11 @@ public function posts()
         return $this->hasMany(Post::class);
     }
 
+    public function comments()
+    {
+        return $this->hasMany(Comment::class);
+    }
+
     public function teams()
     {
         return $this->belongsToMany(Team::class)
diff --git a/tests/Integration/Http/Resources/JsonApi/Fixtures/UserApiResource.php b/tests/Integration/Http/Resources/JsonApi/Fixtures/UserApiResource.php
index a45a8b37fa78..bce50ff6da07 100644
--- a/tests/Integration/Http/Resources/JsonApi/Fixtures/UserApiResource.php
+++ b/tests/Integration/Http/Resources/JsonApi/Fixtures/UserApiResource.php
@@ -8,6 +8,7 @@
 class UserApiResource extends JsonApiResource
 {
     protected array $relationships = [
+        'comments',
         'profile',
         'posts',
         'teams',
diff --git a/tests/Integration/Http/Resources/JsonApi/Fixtures/migrations.php b/tests/Integration/Http/Resources/JsonApi/Fixtures/migrations.php
index e560a3eb970a..26afadca7cb9 100644
--- a/tests/Integration/Http/Resources/JsonApi/Fixtures/migrations.php
+++ b/tests/Integration/Http/Resources/JsonApi/Fixtures/migrations.php
@@ -34,3 +34,11 @@
 
     $table->index(['team_id', 'user_id']);
 });
+
+Schema::create('comments', function (Blueprint $table) {
+    $table->id();
+    $table->foreignId('post_id')->unique();
+    $table->foreignId('user_id')->index()->nullable();
+    $table->text('content');
+    $table->timestamps();
+});
diff --git a/tests/Integration/Http/Resources/JsonApi/JsonApiResourceTest.php b/tests/Integration/Http/Resources/JsonApi/JsonApiResourceTest.php
index 1ba46b92810a..9b4160b3d75b 100644
--- a/tests/Integration/Http/Resources/JsonApi/JsonApiResourceTest.php
+++ b/tests/Integration/Http/Resources/JsonApi/JsonApiResourceTest.php
@@ -2,6 +2,7 @@
 
 namespace Illuminate\Tests\Integration\Http\Resources\JsonApi;
 
+use Illuminate\Tests\Integration\Http\Resources\JsonApi\Fixtures\Comment;
 use Illuminate\Tests\Integration\Http\Resources\JsonApi\Fixtures\Post;
 use Illuminate\Tests\Integration\Http\Resources\JsonApi\Fixtures\Profile;
 use Illuminate\Tests\Integration\Http\Resources\JsonApi\Fixtures\Team;
@@ -188,4 +189,58 @@ public function testItCanGenerateJsonApiResponseWithRelationshipsUsingSparseIncl
                 ],
             ]);
     }
+
+    public function test_it_can_resolve_relationship_with_custom_name_and_resource_class()
+    {
+        $now = $this->freezeSecond();
+
+        $user = User::factory()->create();
+
+        $profile = Profile::factory()->create([
+            'user_id' => $user->getKey(),
+            'date_of_birth' => '2011-06-09',
+            'timezone' => 'America/Chicago',
+        ]);
+
+        [$post1, $post2] = Post::factory()->times(2)->create([
+            'user_id' => $user->getKey(),
+        ]);
+
+        $comments = Comment::factory()->create([
+            'post_id' => $post1->getKey(),
+            'user_id' => $user->getKey(),
+        ]);
+
+        $this->getJson("/posts/{$post1->getKey()}?".http_build_query(['include' => 'author']))
+            ->assertHeader('Content-type', 'application/vnd.api+json')
+            ->assertExactJson([
+                'data' => [
+                    'attributes' => [
+                        'content' => $post1->content,
+                        'title' => $post1->title,
+                    ],
+                    'type' => 'posts',
+                    'id' => (string) $post1->getKey(),
+                    'relationships' => [
+                        'author' => [
+                            'data' => [
+                                'id' => (string) $user->getKey(),
+                                'type' => 'authors',
+                            ],
+                        ]
+                    ]
+                ],
+                'included' => [
+                    [
+                        'attributes' => [
+                            'email' => $user->email,
+                            'name' => $user->name,
+                        ],
+                        'id' => (string) $user->getKey(),
+                        'type' => 'authors',
+                    ],
+                ],
+            ])
+            ->assertJsonMissing(['jsonapi']);
+    }
 }
diff --git a/tests/Integration/Http/Resources/JsonApi/TestCase.php b/tests/Integration/Http/Resources/JsonApi/TestCase.php
index a1644383a7cb..4904345733cc 100644
--- a/tests/Integration/Http/Resources/JsonApi/TestCase.php
+++ b/tests/Integration/Http/Resources/JsonApi/TestCase.php
@@ -5,6 +5,7 @@
 use Illuminate\Foundation\Testing\LazilyRefreshDatabase;
 use Illuminate\Http\Resources\Json\JsonResource;
 use Illuminate\Http\Resources\JsonApi\JsonApiResource;
+use Illuminate\Tests\Integration\Http\Resources\JsonApi\Fixtures\Post;
 use Illuminate\Tests\Integration\Http\Resources\JsonApi\Fixtures\User;
 use Orchestra\Testbench\Attributes\WithConfig;
 use Orchestra\Testbench\Attributes\WithMigration;
@@ -36,6 +37,14 @@ protected function defineRoutes($router)
         $router->get('users/{userId}', function ($userId) {
             return User::find($userId)->toResource();
         });
+
+        $router->get('posts', function () {
+            return Post::paginate(5)->toResourceCollection();
+        });
+
+        $router->get('posts/{postId}', function ($postId) {
+            return Post::find($postId)->toResource();
+        });
     }
 
     /** {@inheritdoc} */

From c93256ea7abb8d13459f87fff7dd49b0bed2c188 Mon Sep 17 00:00:00 2001
From: StyleCI Bot <bot@styleci.io>
Date: Tue, 2 Dec 2025 12:15:40 +0000
Subject: [PATCH 26/48] Apply fixes from StyleCI

---
 .../Http/Resources/JsonApi/Fixtures/CommentApiResource.php    | 1 -
 .../Http/Resources/JsonApi/JsonApiResourceTest.php            | 4 ++--
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/tests/Integration/Http/Resources/JsonApi/Fixtures/CommentApiResource.php b/tests/Integration/Http/Resources/JsonApi/Fixtures/CommentApiResource.php
index 8302d235113e..d874417ebd30 100644
--- a/tests/Integration/Http/Resources/JsonApi/Fixtures/CommentApiResource.php
+++ b/tests/Integration/Http/Resources/JsonApi/Fixtures/CommentApiResource.php
@@ -2,7 +2,6 @@
 
 namespace Illuminate\Tests\Integration\Http\Resources\JsonApi\Fixtures;
 
-use Illuminate\Http\Request;
 use Illuminate\Http\Resources\JsonApi\JsonApiResource;
 
 class CommentApiResource extends JsonApiResource
diff --git a/tests/Integration/Http/Resources/JsonApi/JsonApiResourceTest.php b/tests/Integration/Http/Resources/JsonApi/JsonApiResourceTest.php
index 9b4160b3d75b..59f26d849f37 100644
--- a/tests/Integration/Http/Resources/JsonApi/JsonApiResourceTest.php
+++ b/tests/Integration/Http/Resources/JsonApi/JsonApiResourceTest.php
@@ -227,8 +227,8 @@ public function test_it_can_resolve_relationship_with_custom_name_and_resource_c
                                 'id' => (string) $user->getKey(),
                                 'type' => 'authors',
                             ],
-                        ]
-                    ]
+                        ],
+                    ],
                 ],
                 'included' => [
                     [

From ac5c68e0333b276368cea7fd5fe2f7d90a362428 Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Wed, 3 Dec 2025 10:26:06 +0800
Subject: [PATCH 27/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 src/Illuminate/Http/Resources/JsonApi/RelationResolver.php | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
index 9837f8292ed2..47b775df6cfb 100644
--- a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
+++ b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
@@ -65,6 +65,8 @@ public function resourceClass(): ?string
 
     /**
      * Get the relation resource type.
+     *
+     * @throws \Illuminate\Http\Resources\JsonApi\Exceptions\ResourceIdentificationException
      */
     public function resourceType(Collection|Model $resources, JsonApiRequest $request): ?string
     {

From c5a50bc746ecc44f2aef4975ef97c368d81ccfdb Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Tue, 2 Dec 2025 20:31:27 +0800
Subject: [PATCH 28/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 .../Http/Resources/Json/JsonResource.php           | 11 +++++++++++
 .../Http/Resources/JsonApi/JsonApiResource.php     | 14 +++++++++++++-
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/src/Illuminate/Http/Resources/Json/JsonResource.php b/src/Illuminate/Http/Resources/Json/JsonResource.php
index 02ebce156d8c..16bb7a0ea00c 100644
--- a/src/Illuminate/Http/Resources/Json/JsonResource.php
+++ b/src/Illuminate/Http/Resources/Json/JsonResource.php
@@ -131,6 +131,17 @@ public function resolve($request = null)
      * @return array|\Illuminate\Contracts\Support\Arrayable|\JsonSerializable
      */
     public function toAttributes(Request $request)
+    {
+        return $this->resolveResourceDataToArray($request);
+    }
+
+    /**
+     * Resolve the resource data to an array.
+     *
+     * @param  \Illuminate\Http\Request  $request
+     * @return array
+     */
+    public function resolveResourceDataToArray(Request $request)
     {
         return $this->toArray($request);
     }
diff --git a/src/Illuminate/Http/Resources/JsonApi/JsonApiResource.php b/src/Illuminate/Http/Resources/JsonApi/JsonApiResource.php
index 003ffa41a6d1..2cfb19f506d6 100644
--- a/src/Illuminate/Http/Resources/JsonApi/JsonApiResource.php
+++ b/src/Illuminate/Http/Resources/JsonApi/JsonApiResource.php
@@ -149,10 +149,22 @@ public function with($request)
     public function resolve($request = null)
     {
         return [
-            'data' => $this->resolveResourceData($this->resolveJsonApiRequestFrom($request ?? $this->resolveRequestFromContainer())),
+            'data' => $this->resolveResourceDataToArray($this->resolveJsonApiRequestFrom($request ?? $this->resolveRequestFromContainer())),
         ];
     }
 
+    /**
+     * Resolve the resource data to an array.
+     *
+     * @param  \Illuminate\Http\Request  $request
+     * @return array
+     */
+    #[\Override]
+    public function resolveResourceDataToArray(Request $request)
+    {
+        return $this->resolveResourceData($request);
+    }
+
     /**
      * Customize the outgoing response for the resource.
      */

From ade3d72c47bc0d5a9007d3d1fd38c38918479621 Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Wed, 3 Dec 2025 11:44:12 +0800
Subject: [PATCH 29/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 src/Illuminate/Http/Resources/Json/JsonResource.php         | 4 ++--
 .../Resources/JsonApi/Concerns/ResolvesJsonApiElements.php  | 2 +-
 src/Illuminate/Http/Resources/JsonApi/JsonApiResource.php   | 6 +++---
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/Illuminate/Http/Resources/Json/JsonResource.php b/src/Illuminate/Http/Resources/Json/JsonResource.php
index 16bb7a0ea00c..33c02cbc7b14 100644
--- a/src/Illuminate/Http/Resources/Json/JsonResource.php
+++ b/src/Illuminate/Http/Resources/Json/JsonResource.php
@@ -132,7 +132,7 @@ public function resolve($request = null)
      */
     public function toAttributes(Request $request)
     {
-        return $this->resolveResourceDataToArray($request);
+        return $this->resolveResourceData($request);
     }
 
     /**
@@ -141,7 +141,7 @@ public function toAttributes(Request $request)
      * @param  \Illuminate\Http\Request  $request
      * @return array
      */
-    public function resolveResourceDataToArray(Request $request)
+    public function resolveResourceData(Request $request)
     {
         return $this->toArray($request);
     }
diff --git a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
index 5d82d38c1656..d13097cfcf66 100644
--- a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
+++ b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
@@ -37,7 +37,7 @@ trait ResolvesJsonApiElements
     /**
      * Resolves `data` for the resource.
      */
-    public function resolveResourceData(JsonApiRequest $request): array
+    public function resolveJsonApiResourceObject(JsonApiRequest $request): array
     {
         $resourceType = $this->resolveResourceType($request);
 
diff --git a/src/Illuminate/Http/Resources/JsonApi/JsonApiResource.php b/src/Illuminate/Http/Resources/JsonApi/JsonApiResource.php
index 2cfb19f506d6..b5b1f34f6c72 100644
--- a/src/Illuminate/Http/Resources/JsonApi/JsonApiResource.php
+++ b/src/Illuminate/Http/Resources/JsonApi/JsonApiResource.php
@@ -149,7 +149,7 @@ public function with($request)
     public function resolve($request = null)
     {
         return [
-            'data' => $this->resolveResourceDataToArray($this->resolveJsonApiRequestFrom($request ?? $this->resolveRequestFromContainer())),
+            'data' => $this->resolveResourceData($this->resolveJsonApiRequestFrom($request ?? $this->resolveRequestFromContainer())),
         ];
     }
 
@@ -160,9 +160,9 @@ public function resolve($request = null)
      * @return array
      */
     #[\Override]
-    public function resolveResourceDataToArray(Request $request)
+    public function resolveResourceData(Request $request)
     {
-        return $this->resolveResourceData($request);
+        return $this->resolveJsonApiResourceObject($request);
     }
 
     /**

From 02939748d68ad5054c485960f89f83cf097b3f24 Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Wed, 3 Dec 2025 12:04:56 +0800
Subject: [PATCH 30/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 .../Concerns/ResolvesJsonApiElements.php      | 31 ++++++++++++++++---
 .../Resources/JsonApi/JsonApiResource.php     |  2 +-
 2 files changed, 28 insertions(+), 5 deletions(-)

diff --git a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
index d13097cfcf66..8ec4f8fd0240 100644
--- a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
+++ b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
@@ -22,6 +22,11 @@
 
 trait ResolvesJsonApiElements
 {
+    /**
+     * Determine whether resource use included and fields from the request object.
+     */
+    protected bool $usesRequestQueryString = true;
+
     /**
      * Cached loaded relationships map.
      *
@@ -34,10 +39,22 @@ trait ResolvesJsonApiElements
      */
     protected array $loadedRelationshipIdentifiers = [];
 
+    public function withRequestQueryString(bool $value = true)
+    {
+        $this->usesRequestQueryString = $value;
+
+        return $this;
+    }
+
+    public function withoutRequestQueryString()
+    {
+        return $this->withRequestQueryString(false);
+    }
+
     /**
      * Resolves `data` for the resource.
      */
-    public function resolveJsonApiResourceObject(JsonApiRequest $request): array
+    protected function resolveResourceObject(JsonApiRequest $request): array
     {
         $resourceType = $this->resolveResourceType($request);
 
@@ -108,7 +125,10 @@ protected function resolveResourceAttributes(JsonApiRequest $request, string $re
             $data = $data->jsonSerialize();
         }
 
-        $sparseFieldset = $request->sparseFields($resourceType);
+        $sparseFieldset = match ($this->usesRequestQueryString) {
+            true => $request->sparseFields($resourceType),
+            default => [],
+        };
 
         $data = (new Collection($data))
             ->mapWithKeys(fn ($value, $key) => is_int($key) ? [$value => $this->resource->{$value}] : [$key => $value])
@@ -152,7 +172,10 @@ protected function compileResourceRelationships(JsonApiRequest $request): void
             return;
         }
 
-        $sparseIncluded = $request->sparseIncluded();
+        $sparseIncluded = match ($this->usesRequestQueryString) {
+            true => $request->sparseIncluded(),
+            default => [],
+        };
 
         $resourceRelationships = (new Collection($this->toRelationships($request)))
             ->mapWithKeys(
@@ -244,7 +267,7 @@ public function resolveIncludedResources(JsonApiRequest $request): array
                 $resourceInstance = new JsonApiResource($resourceInstance->resource);
             }
 
-            $relationsData = $resourceInstance->resolve($request);
+            $relationsData = $resourceInstance->withoutRequestQueryString()->resolve($request);
 
             $relations->push(array_filter([
                 'id' => $id,
diff --git a/src/Illuminate/Http/Resources/JsonApi/JsonApiResource.php b/src/Illuminate/Http/Resources/JsonApi/JsonApiResource.php
index b5b1f34f6c72..e764132d197e 100644
--- a/src/Illuminate/Http/Resources/JsonApi/JsonApiResource.php
+++ b/src/Illuminate/Http/Resources/JsonApi/JsonApiResource.php
@@ -162,7 +162,7 @@ public function resolve($request = null)
     #[\Override]
     public function resolveResourceData(Request $request)
     {
-        return $this->resolveJsonApiResourceObject($request);
+        return $this->resolveResourceObject($request);
     }
 
     /**

From 7f4b3f086ecc770effdfdbc2804f8fd4143fbd2d Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Wed, 3 Dec 2025 12:47:20 +0800
Subject: [PATCH 31/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 .../Concerns/ResolvesJsonApiElements.php      | 29 ++++++---
 .../Resources/JsonApi/JsonApiResourceTest.php | 61 ++++++++++++++++++-
 2 files changed, 81 insertions(+), 9 deletions(-)

diff --git a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
index 8ec4f8fd0240..af156aca515f 100644
--- a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
+++ b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
@@ -27,6 +27,11 @@ trait ResolvesJsonApiElements
      */
     protected bool $usesRequestQueryString = true;
 
+    /**
+     * Determine whether included relationship for the resource from eager loaded relationship.
+     */
+    protected bool $usesIncludedFromLoadedRelationships = false;
+
     /**
      * Cached loaded relationships map.
      *
@@ -51,6 +56,13 @@ public function withoutRequestQueryString()
         return $this->withRequestQueryString(false);
     }
 
+    public function withIncludedFromLoadedRelationship()
+    {
+        $this->usesIncludedFromLoadedRelationships = true;
+
+        return $this;
+    }
+
     /**
      * Resolves `data` for the resource.
      */
@@ -172,17 +184,18 @@ protected function compileResourceRelationships(JsonApiRequest $request): void
             return;
         }
 
-        $sparseIncluded = match ($this->usesRequestQueryString) {
-            true => $request->sparseIncluded(),
+        $sparseIncluded = match (true) {
+            $this->usesRequestQueryString === true => $request->sparseIncluded(),
+            $this->usesRequestQueryString === false && $this->usesIncludedFromLoadedRelationships === true => array_keys($this->resource->getRelations()),
             default => [],
         };
 
         $resourceRelationships = (new Collection($this->toRelationships($request)))
-            ->mapWithKeys(
-                fn ($value, $key) => is_int($key) ? [$value => new RelationResolver($value)] : [$key => new RelationResolver($key, $value)]
-            )->filter(
-                fn ($value, $key) => in_array($key, $sparseIncluded)
-            );
+            ->mapWithKeys(function ($value, $key) {
+                $relationResolver = is_int($key) ? new RelationResolver($value) : new RelationResolver($key, $value);
+
+                return [$relationResolver->relationName => $relationResolver];
+            })->filter(fn ($value, $key) => in_array($key, $sparseIncluded));
 
         $resourceRelationshipKeys = $resourceRelationships->keys();
 
@@ -267,7 +280,7 @@ public function resolveIncludedResources(JsonApiRequest $request): array
                 $resourceInstance = new JsonApiResource($resourceInstance->resource);
             }
 
-            $relationsData = $resourceInstance->withoutRequestQueryString()->resolve($request);
+            $relationsData = $resourceInstance->withoutRequestQueryString()->withIncludedFromLoadedRelationship()->resolve($request);
 
             $relations->push(array_filter([
                 'id' => $id,
diff --git a/tests/Integration/Http/Resources/JsonApi/JsonApiResourceTest.php b/tests/Integration/Http/Resources/JsonApi/JsonApiResourceTest.php
index 59f26d849f37..38bd1fdb9331 100644
--- a/tests/Integration/Http/Resources/JsonApi/JsonApiResourceTest.php
+++ b/tests/Integration/Http/Resources/JsonApi/JsonApiResourceTest.php
@@ -206,7 +206,7 @@ public function test_it_can_resolve_relationship_with_custom_name_and_resource_c
             'user_id' => $user->getKey(),
         ]);
 
-        $comments = Comment::factory()->create([
+        $comment = Comment::factory()->create([
             'post_id' => $post1->getKey(),
             'user_id' => $user->getKey(),
         ]);
@@ -243,4 +243,63 @@ public function test_it_can_resolve_relationship_with_custom_name_and_resource_c
             ])
             ->assertJsonMissing(['jsonapi']);
     }
+
+    public function test_it_can_resolve_relationship_with_nested_relationship()
+    {
+        $now = $this->freezeSecond();
+
+        $user = User::factory()->create();
+
+        $profile = Profile::factory()->create([
+            'user_id' => $user->getKey(),
+            'date_of_birth' => '2011-06-09',
+            'timezone' => 'America/Chicago',
+        ]);
+
+        [$post1, $post2] = Post::factory()->times(2)->create([
+            'user_id' => $user->getKey(),
+        ]);
+
+        $comment = Comment::factory()->create([
+            'post_id' => $post1->getKey(),
+            'user_id' => $user->getKey(),
+        ]);
+
+        $this->getJson("/posts/{$post1->getKey()}?".http_build_query(['include' => 'author,comments.commenter']))
+            ->assertHeader('Content-type', 'application/vnd.api+json')
+            ->assertExactJson([
+                'data' => [
+                    'attributes' => [
+                        'content' => $post1->content,
+                        'title' => $post1->title,
+                    ],
+                    'type' => 'posts',
+                    'id' => (string) $post1->getKey(),
+                    'relationships' => [
+                        'author' => [
+                            'data' => [
+                                'id' => (string) $user->getKey(),
+                                'type' => 'authors',
+                            ],
+                        ],
+                        'comments' => [
+                            'data' => [
+                                ['id' => (string) $comment->getKey(), 'type' => 'comments'],
+                            ],
+                        ],
+                    ],
+                ],
+                'included' => [
+                    [
+                        'attributes' => [
+                            'email' => $user->email,
+                            'name' => $user->name,
+                        ],
+                        'id' => (string) $user->getKey(),
+                        'type' => 'authors',
+                    ],
+                ],
+            ])
+            ->assertJsonMissing(['jsonapi']);
+    }
 }

From bac37e2c0c47673d00d8eadd028324efb83630a6 Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Wed, 3 Dec 2025 16:56:03 +0800
Subject: [PATCH 32/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 .../Concerns/ResolvesJsonApiElements.php      |  9 ++--
 .../Http/Resources/JsonApi/JsonApiRequest.php | 45 +++++++++++++++----
 .../Resources/JsonApi/RelationResolver.php    | 24 ++++++++--
 .../Resources/JsonApi/Fixtures/Comment.php    |  2 +
 .../JsonApi/Fixtures/PostApiResource.php      |  1 +
 .../JsonApi/Fixtures/UserApiResource.php      |  6 +++
 .../Resources/JsonApi/JsonApiResourceTest.php | 15 +++++++
 7 files changed, 84 insertions(+), 18 deletions(-)

diff --git a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
index af156aca515f..8fabb5f82c6f 100644
--- a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
+++ b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
@@ -185,9 +185,8 @@ protected function compileResourceRelationships(JsonApiRequest $request): void
         }
 
         $sparseIncluded = match (true) {
-            $this->usesRequestQueryString === true => $request->sparseIncluded(),
-            $this->usesRequestQueryString === false && $this->usesIncludedFromLoadedRelationships === true => array_keys($this->resource->getRelations()),
-            default => [],
+            $this->usesIncludedFromLoadedRelationships => array_keys($this->resource->getRelations()),
+            default => $request->sparseIncluded(),
         };
 
         $resourceRelationships = (new Collection($this->toRelationships($request)))
@@ -199,12 +198,12 @@ protected function compileResourceRelationships(JsonApiRequest $request): void
 
         $resourceRelationshipKeys = $resourceRelationships->keys();
 
-        $this->resource->loadMissing($resourceRelationshipKeys->all());
+        $this->resource->loadMissing($resourceRelationshipKeys->all() ?? []);
 
         $this->loadedRelationshipsMap = new WeakMap;
 
         $this->loadedRelationshipIdentifiers = $resourceRelationships->mapWithKeys(function (RelationResolver $relationResolver, $key) use ($request) {
-            $relatedModels = $relationResolver->handle($this->resource);
+            $relatedModels = $relationResolver->handle($this->resource)->loadMissing($request->sparseIncluded($key));
             $relatedResourceClass = $relationResolver->resourceClass();
 
             // Relationship is a collection of models...
diff --git a/src/Illuminate/Http/Resources/JsonApi/JsonApiRequest.php b/src/Illuminate/Http/Resources/JsonApi/JsonApiRequest.php
index c5f0f194b1bb..f85376563bd4 100644
--- a/src/Illuminate/Http/Resources/JsonApi/JsonApiRequest.php
+++ b/src/Illuminate/Http/Resources/JsonApi/JsonApiRequest.php
@@ -4,30 +4,57 @@
 
 use Illuminate\Http\Request;
 use Illuminate\Support\Arr;
+use Illuminate\Support\Collection;
 
 class JsonApiRequest extends Request
 {
+    protected ?array $cachedSparseFields = null;
+
+    protected ?array $cachedSparseIncluded = null;
+
     /**
      * Get the request's included fields.
      */
     public function sparseFields(string $key): array
     {
-        $fieldsets = Arr::get($this->array('fields'), $key, '');
+        if (is_null($this->cachedSparseFields)) {
+            $this->cachedSparseFields = (new Collection($this->array('fields')))
+                ->transform(fn ($fieldsets) => empty($fieldsets) ? [] : explode(',', $fieldsets))
+                ->all();
+        }
 
-        return empty($fieldsets)
-            ? []
-            : explode(',', $fieldsets);
+        return $this->cachedSparseFields[$key] ?? [];
     }
 
     /**
      * Get the request's included relationships.
      */
-    public function sparseIncluded(): array
+    public function sparseIncluded(?string $key = null): ?array
     {
-        $included = (string) $this->string('include', '');
+        if (is_null($this->cachedSparseIncluded)) {
+            $included = (string) $this->string('include', '');
+
+            $this->cachedSparseIncluded = (new Collection(empty($included) ? [] : explode(',', $included)))
+                ->transform(function ($item) {
+                    $with = null;
+
+                    if (str_contains($item, '.')) {
+                        [$relation, $with] = explode('.', $item, 2);
+                    } else {
+                        $relation = $item;
+                    }
+
+                    return ['relation' => $relation, 'with' => $with];
+                })->mapToGroups(fn ($item) => [$item['relation'] => $item['with']])
+                ->toArray();
+        }
+
+        if (is_null($key)) {
+            return array_keys($this->cachedSparseIncluded);
+        }
 
-        return empty($included)
-            ? []
-            : explode(',', $included);
+        return transform($this->cachedSparseIncluded[$key] ?? null, function ($value) {
+            return array_filter($value);
+        }) ?? [];
     }
 }
diff --git a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
index 47b775df6cfb..def249c0a6cf 100644
--- a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
+++ b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
@@ -12,6 +12,13 @@
  */
 class RelationResolver
 {
+    /**
+     * The relation name.
+     */
+    public string $relationName;
+
+    public ?string $relationWith = null;
+
     /**
      * The relation resolver.
      *
@@ -31,10 +38,15 @@ class RelationResolver
      *
      * @param  \Closure(mixed):(\Illuminate\Database\Eloquent\Collection|\Illuminate\Database\Eloquent\Model|null)|class-string<\Illuminate\Http\Resources\JsonApi\JsonApiResource>|null  $resolver
      */
-    public function __construct(
-        public string $relationName,
-        Closure|string|null $resolver = null
-    ) {
+    public function __construct(string $relationName, Closure|string|null $resolver = null)
+    {
+        if (str_contains($relationName, '.')) {
+            [$this->relationName, $this->relationWith] = explode('.', $relationName, 1);
+        } else {
+            $this->relationName = $relationName;
+            $this->relationWith = null;
+        }
+
         $this->relationResolver = match (true) {
             $resolver instanceof Closure => $resolver,
             default => fn ($resource) => $resource->getRelation($this->relationName),
@@ -50,6 +62,10 @@ public function __construct(
      */
     public function handle(mixed $resource): Collection|Model|null
     {
+        if (! empty($this->relationWith)) {
+            $resource->loadMissing($this->relationWith);
+        }
+
         return value($this->relationResolver, $resource);
     }
 
diff --git a/tests/Integration/Http/Resources/JsonApi/Fixtures/Comment.php b/tests/Integration/Http/Resources/JsonApi/Fixtures/Comment.php
index 05a516624d4b..aa9d4926db88 100644
--- a/tests/Integration/Http/Resources/JsonApi/Fixtures/Comment.php
+++ b/tests/Integration/Http/Resources/JsonApi/Fixtures/Comment.php
@@ -3,10 +3,12 @@
 namespace Illuminate\Tests\Integration\Http\Resources\JsonApi\Fixtures;
 
 use Illuminate\Database\Eloquent\Attributes\UseFactory;
+use Illuminate\Database\Eloquent\Attributes\UseResource;
 use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\Model;
 
 #[UseFactory(CommentFactory::class)]
+#[UseResource(CommentApiResource::class)]
 class Comment extends Model
 {
     use HasFactory;
diff --git a/tests/Integration/Http/Resources/JsonApi/Fixtures/PostApiResource.php b/tests/Integration/Http/Resources/JsonApi/Fixtures/PostApiResource.php
index dd847d304c5b..874b703577a3 100644
--- a/tests/Integration/Http/Resources/JsonApi/Fixtures/PostApiResource.php
+++ b/tests/Integration/Http/Resources/JsonApi/Fixtures/PostApiResource.php
@@ -13,5 +13,6 @@ class PostApiResource extends JsonApiResource
 
     protected array $relationships = [
         'author' => AuthorApiResource::class,
+        'comments',
     ];
 }
diff --git a/tests/Integration/Http/Resources/JsonApi/Fixtures/UserApiResource.php b/tests/Integration/Http/Resources/JsonApi/Fixtures/UserApiResource.php
index bce50ff6da07..6fe76f81db1d 100644
--- a/tests/Integration/Http/Resources/JsonApi/Fixtures/UserApiResource.php
+++ b/tests/Integration/Http/Resources/JsonApi/Fixtures/UserApiResource.php
@@ -22,4 +22,10 @@ public function toAttributes(Request $request)
             'email' => $this->email,
         ];
     }
+
+    #[\Override]
+    public function toType(Request $request)
+    {
+        return 'users';
+    }
 }
diff --git a/tests/Integration/Http/Resources/JsonApi/JsonApiResourceTest.php b/tests/Integration/Http/Resources/JsonApi/JsonApiResourceTest.php
index 38bd1fdb9331..e020455e6c19 100644
--- a/tests/Integration/Http/Resources/JsonApi/JsonApiResourceTest.php
+++ b/tests/Integration/Http/Resources/JsonApi/JsonApiResourceTest.php
@@ -298,6 +298,21 @@ public function test_it_can_resolve_relationship_with_nested_relationship()
                         'id' => (string) $user->getKey(),
                         'type' => 'authors',
                     ],
+                    [
+                        'attributes' => [
+                            'content' => $comment->content,
+                        ],
+                        'id' => (string) $comment->getKey(),
+                        'type' => 'comments',
+                        'relationships' => [
+                            'commenter' => [
+                                'data' => [
+                                    'id' => (string) $user->getKey(),
+                                    'type' => 'users',
+                                ],
+                            ],
+                        ],
+                    ],
                 ],
             ])
             ->assertJsonMissing(['jsonapi']);

From 29f6f53d56a999e3523eabead90983dada75bba2 Mon Sep 17 00:00:00 2001
From: StyleCI Bot <bot@styleci.io>
Date: Wed, 3 Dec 2025 08:56:29 +0000
Subject: [PATCH 33/48] Apply fixes from StyleCI

---
 src/Illuminate/Http/Resources/JsonApi/JsonApiRequest.php | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/Illuminate/Http/Resources/JsonApi/JsonApiRequest.php b/src/Illuminate/Http/Resources/JsonApi/JsonApiRequest.php
index f85376563bd4..e2c29840b8c0 100644
--- a/src/Illuminate/Http/Resources/JsonApi/JsonApiRequest.php
+++ b/src/Illuminate/Http/Resources/JsonApi/JsonApiRequest.php
@@ -3,7 +3,6 @@
 namespace Illuminate\Http\Resources\JsonApi;
 
 use Illuminate\Http\Request;
-use Illuminate\Support\Arr;
 use Illuminate\Support\Collection;
 
 class JsonApiRequest extends Request

From d9d9d97c18d60c58ad2b5494a0ae88e659623add Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Wed, 3 Dec 2025 17:36:27 +0800
Subject: [PATCH 34/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 .../Resources/JsonApi/Concerns/ResolvesJsonApiElements.php  | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
index 8fabb5f82c6f..d8bdfcaefad9 100644
--- a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
+++ b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
@@ -203,9 +203,13 @@ protected function compileResourceRelationships(JsonApiRequest $request): void
         $this->loadedRelationshipsMap = new WeakMap;
 
         $this->loadedRelationshipIdentifiers = $resourceRelationships->mapWithKeys(function (RelationResolver $relationResolver, $key) use ($request) {
-            $relatedModels = $relationResolver->handle($this->resource)->loadMissing($request->sparseIncluded($key));
+            $relatedModels = $relationResolver->handle($this->resource);
             $relatedResourceClass = $relationResolver->resourceClass();
 
+            if (! is_null($relatedModels)) {
+                $relatedModels->loadMissing($request->sparseIncluded($key));
+            }
+
             // Relationship is a collection of models...
             if ($relatedModels instanceof Collection) {
                 $relatedModels = $relatedModels->values();

From 4eef51c38e9134e102aab9d43930408eefeb348f Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Wed, 3 Dec 2025 17:37:12 +0800
Subject: [PATCH 35/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 src/Illuminate/Http/Resources/JsonApi/RelationResolver.php | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
index def249c0a6cf..9873c7f5e9e1 100644
--- a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
+++ b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
@@ -41,7 +41,7 @@ class RelationResolver
     public function __construct(string $relationName, Closure|string|null $resolver = null)
     {
         if (str_contains($relationName, '.')) {
-            [$this->relationName, $this->relationWith] = explode('.', $relationName, 1);
+            [$this->relationName, $this->relationWith] = explode('.', $relationName, 2);
         } else {
             $this->relationName = $relationName;
             $this->relationWith = null;
@@ -62,10 +62,6 @@ public function __construct(string $relationName, Closure|string|null $resolver
      */
     public function handle(mixed $resource): Collection|Model|null
     {
-        if (! empty($this->relationWith)) {
-            $resource->loadMissing($this->relationWith);
-        }
-
         return value($this->relationResolver, $resource);
     }
 

From 17faaff2eb82cf920a92acd2a5e1473504af9728 Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Wed, 3 Dec 2025 17:40:12 +0800
Subject: [PATCH 36/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 .../Http/Resources/JsonApi/RelationResolver.php  | 16 +---------------
 1 file changed, 1 insertion(+), 15 deletions(-)

diff --git a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
index 9873c7f5e9e1..94b97dd41814 100644
--- a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
+++ b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
@@ -12,13 +12,6 @@
  */
 class RelationResolver
 {
-    /**
-     * The relation name.
-     */
-    public string $relationName;
-
-    public ?string $relationWith = null;
-
     /**
      * The relation resolver.
      *
@@ -38,15 +31,8 @@ class RelationResolver
      *
      * @param  \Closure(mixed):(\Illuminate\Database\Eloquent\Collection|\Illuminate\Database\Eloquent\Model|null)|class-string<\Illuminate\Http\Resources\JsonApi\JsonApiResource>|null  $resolver
      */
-    public function __construct(string $relationName, Closure|string|null $resolver = null)
+    public function __construct(public string $relationName, Closure|string|null $resolver = null)
     {
-        if (str_contains($relationName, '.')) {
-            [$this->relationName, $this->relationWith] = explode('.', $relationName, 2);
-        } else {
-            $this->relationName = $relationName;
-            $this->relationWith = null;
-        }
-
         $this->relationResolver = match (true) {
             $resolver instanceof Closure => $resolver,
             default => fn ($resource) => $resource->getRelation($this->relationName),

From 29a4a5d6c3d6a1f4432c41e52dc8cedbbf18b4e9 Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Thu, 4 Dec 2025 07:22:54 +0800
Subject: [PATCH 37/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 .../Http/Resources/Json/JsonResource.php       | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/src/Illuminate/Http/Resources/Json/JsonResource.php b/src/Illuminate/Http/Resources/Json/JsonResource.php
index 33c02cbc7b14..545b16d9cac5 100644
--- a/src/Illuminate/Http/Resources/Json/JsonResource.php
+++ b/src/Illuminate/Http/Resources/Json/JsonResource.php
@@ -132,7 +132,7 @@ public function resolve($request = null)
      */
     public function toAttributes(Request $request)
     {
-        return $this->resolveResourceData($request);
+        return $this->toArray($request);
     }
 
     /**
@@ -143,7 +143,13 @@ public function toAttributes(Request $request)
      */
     public function resolveResourceData(Request $request)
     {
-        return $this->toArray($request);
+        if (is_null($this->resource)) {
+            return [];
+        }
+
+        return is_array($this->resource)
+            ? $this->resource
+            : $this->resource->toArray();
     }
 
     /**
@@ -154,13 +160,7 @@ public function resolveResourceData(Request $request)
      */
     public function toArray(Request $request)
     {
-        if (is_null($this->resource)) {
-            return [];
-        }
-
-        return is_array($this->resource)
-            ? $this->resource
-            : $this->resource->toArray();
+        return $this->resolveResourceData($request);
     }
 
     /**

From b400eecb26c34e84acca3277960127015c8e145e Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Thu, 4 Dec 2025 07:25:53 +0800
Subject: [PATCH 38/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 .../Http/Resources/Json/JsonResource.php       | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/src/Illuminate/Http/Resources/Json/JsonResource.php b/src/Illuminate/Http/Resources/Json/JsonResource.php
index 545b16d9cac5..ebef5e7aab8b 100644
--- a/src/Illuminate/Http/Resources/Json/JsonResource.php
+++ b/src/Illuminate/Http/Resources/Json/JsonResource.php
@@ -111,7 +111,7 @@ protected static function newCollection($resource)
      */
     public function resolve($request = null)
     {
-        $data = $this->toAttributes(
+        $data = $this->resolveResourceData(
             $request ?: $this->resolveRequestFromContainer()
         );
 
@@ -143,13 +143,7 @@ public function toAttributes(Request $request)
      */
     public function resolveResourceData(Request $request)
     {
-        if (is_null($this->resource)) {
-            return [];
-        }
-
-        return is_array($this->resource)
-            ? $this->resource
-            : $this->resource->toArray();
+        return $this->toAttributes($request);
     }
 
     /**
@@ -160,7 +154,13 @@ public function resolveResourceData(Request $request)
      */
     public function toArray(Request $request)
     {
-        return $this->resolveResourceData($request);
+        if (is_null($this->resource)) {
+            return [];
+        }
+
+        return is_array($this->resource)
+            ? $this->resource
+            : $this->resource->toArray();
     }
 
     /**

From 17a7b7ff1358552b59bfc652d870ac328704b1d9 Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Thu, 4 Dec 2025 07:36:18 +0800
Subject: [PATCH 39/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 src/Illuminate/Http/Resources/Json/JsonResource.php | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/Illuminate/Http/Resources/Json/JsonResource.php b/src/Illuminate/Http/Resources/Json/JsonResource.php
index ebef5e7aab8b..7590a95d8eb0 100644
--- a/src/Illuminate/Http/Resources/Json/JsonResource.php
+++ b/src/Illuminate/Http/Resources/Json/JsonResource.php
@@ -132,6 +132,10 @@ public function resolve($request = null)
      */
     public function toAttributes(Request $request)
     {
+        if (property_exists($this, 'attributes')) {
+            return $this->attributes;
+        }
+
         return $this->toArray($request);
     }
 

From e76de92961958c46ef40934dbd2334a7584ed4dd Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Thu, 4 Dec 2025 07:43:07 +0800
Subject: [PATCH 40/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 .../JsonApi/Concerns/ResolvesJsonApiElements.php     | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
index d8bdfcaefad9..97540e5dd2e2 100644
--- a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
+++ b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
@@ -338,8 +338,16 @@ public static function resourceTypeFromModel(Model $model): string
 
         $morphMap = Relation::getMorphAlias($modelClassName);
 
-        return Str::of(
+        return static::normalizeResourceType(
             $morphMap !== $modelClassName ? $morphMap : class_basename($modelClassName)
-        )->snake()->pluralStudly();
+        );
+    }
+
+    /**
+     * Normalize the resource type.
+     */
+    public static function normalizeResourceType(string $value): string
+    {
+        return Str::of($value)->snake()->pluralStudly();
     }
 }

From 48042f35c9e66b84478b4a64768284ef6e155a68 Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Thu, 4 Dec 2025 07:45:56 +0800
Subject: [PATCH 41/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 src/Illuminate/Http/Resources/JsonApi/JsonApiRequest.php | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/Illuminate/Http/Resources/JsonApi/JsonApiRequest.php b/src/Illuminate/Http/Resources/JsonApi/JsonApiRequest.php
index e2c29840b8c0..c869f1382578 100644
--- a/src/Illuminate/Http/Resources/JsonApi/JsonApiRequest.php
+++ b/src/Illuminate/Http/Resources/JsonApi/JsonApiRequest.php
@@ -7,8 +7,14 @@
 
 class JsonApiRequest extends Request
 {
+    /**
+     * Cached sparse fieldset.
+     */
     protected ?array $cachedSparseFields = null;
 
+    /**
+     * Cached sparse included.
+     */
     protected ?array $cachedSparseIncluded = null;
 
     /**

From 3ffb5c57d4cdc45eb705a55386b75ec3a7db1ca5 Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Thu, 4 Dec 2025 10:52:01 +0800
Subject: [PATCH 42/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 .../Concerns/ResolvesJsonApiElements.php      | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
index 97540e5dd2e2..df758426f99c 100644
--- a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
+++ b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
@@ -44,6 +44,11 @@ trait ResolvesJsonApiElements
      */
     protected array $loadedRelationshipIdentifiers = [];
 
+    /**
+     * Determine relationships should rely on request's query string.
+     *
+     * @return $this
+     */
     public function withRequestQueryString(bool $value = true)
     {
         $this->usesRequestQueryString = $value;
@@ -51,12 +56,22 @@ public function withRequestQueryString(bool $value = true)
         return $this;
     }
 
+    /**
+     * Determine relationships should not be relied on request's query string.
+     *
+     * @return $this
+     */
     public function withoutRequestQueryString()
     {
         return $this->withRequestQueryString(false);
     }
 
-    public function withIncludedFromLoadedRelationship()
+    /**
+     * Determine relationship should include loaded relationships.
+     *
+     * @return $this
+     */
+    public function withIncludedFromLoadedRelationships()
     {
         $this->usesIncludedFromLoadedRelationships = true;
 
@@ -283,7 +298,7 @@ public function resolveIncludedResources(JsonApiRequest $request): array
                 $resourceInstance = new JsonApiResource($resourceInstance->resource);
             }
 
-            $relationsData = $resourceInstance->withoutRequestQueryString()->withIncludedFromLoadedRelationship()->resolve($request);
+            $relationsData = $resourceInstance->withoutRequestQueryString()->withIncludedFromLoadedRelationships()->resolve($request);
 
             $relations->push(array_filter([
                 'id' => $id,

From ad152087476deaee4e63f47e4909c613124f0f08 Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Thu, 4 Dec 2025 11:11:28 +0800
Subject: [PATCH 43/48] wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
---
 .../Integration/Http/Resources/JsonApi/TestCase.php  | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/tests/Integration/Http/Resources/JsonApi/TestCase.php b/tests/Integration/Http/Resources/JsonApi/TestCase.php
index 4904345733cc..12afc785818e 100644
--- a/tests/Integration/Http/Resources/JsonApi/TestCase.php
+++ b/tests/Integration/Http/Resources/JsonApi/TestCase.php
@@ -2,9 +2,10 @@
 
 namespace Illuminate\Tests\Integration\Http\Resources\JsonApi;
 
+use Illuminate\Database\Eloquent\Model;
 use Illuminate\Foundation\Testing\LazilyRefreshDatabase;
-use Illuminate\Http\Resources\Json\JsonResource;
 use Illuminate\Http\Resources\JsonApi\JsonApiResource;
+use Illuminate\Http\Resources\Json\JsonResource;
 use Illuminate\Tests\Integration\Http\Resources\JsonApi\Fixtures\Post;
 use Illuminate\Tests\Integration\Http\Resources\JsonApi\Fixtures\User;
 use Orchestra\Testbench\Attributes\WithConfig;
@@ -16,6 +17,15 @@ abstract class TestCase extends \Orchestra\Testbench\TestCase
 {
     use LazilyRefreshDatabase;
 
+    /** {@inheritdoc} */
+    #[\Override]
+    protected function setUp(): void
+    {
+        Model::shouldBeStrict(true);
+
+        parent::setUp();
+    }
+
     /** {@inheritdoc} */
     #[\Override]
     protected function tearDown(): void

From 7f75fb0d8bb87df48ef3611239d0e24ea82ed442 Mon Sep 17 00:00:00 2001
From: StyleCI Bot <bot@styleci.io>
Date: Thu, 4 Dec 2025 03:11:51 +0000
Subject: [PATCH 44/48] Apply fixes from StyleCI

---
 tests/Integration/Http/Resources/JsonApi/TestCase.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/Integration/Http/Resources/JsonApi/TestCase.php b/tests/Integration/Http/Resources/JsonApi/TestCase.php
index 12afc785818e..aa87168d426a 100644
--- a/tests/Integration/Http/Resources/JsonApi/TestCase.php
+++ b/tests/Integration/Http/Resources/JsonApi/TestCase.php
@@ -4,8 +4,8 @@
 
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Foundation\Testing\LazilyRefreshDatabase;
-use Illuminate\Http\Resources\JsonApi\JsonApiResource;
 use Illuminate\Http\Resources\Json\JsonResource;
+use Illuminate\Http\Resources\JsonApi\JsonApiResource;
 use Illuminate\Tests\Integration\Http\Resources\JsonApi\Fixtures\Post;
 use Illuminate\Tests\Integration\Http\Resources\JsonApi\Fixtures\User;
 use Orchestra\Testbench\Attributes\WithConfig;

From 2ec397252c536d4ad79136e3202967274434f124 Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Thu, 4 Dec 2025 21:29:53 +0800
Subject: [PATCH 45/48] [JSON:API] Handles Nested Relationship (#58009)

* wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>

* Apply fixes from StyleCI

* wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>

* wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>

* Apply fixes from StyleCI

* wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>

* wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>

* wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>

* wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>

* wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>

* Apply fixes from StyleCI

* wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>

* wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>

* wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>

* wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>

* Apply fixes from StyleCI

* wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>

* wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>

* Update src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php

---------

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>
Co-authored-by: StyleCI Bot <bot@styleci.io>
---
 .../Concerns/ResolvesJsonApiElements.php      | 165 ++++++++++++------
 .../Resources/JsonApi/JsonApiResourceTest.php |   9 +
 2 files changed, 119 insertions(+), 55 deletions(-)

diff --git a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
index df758426f99c..e0efca7271b7 100644
--- a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
+++ b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
@@ -2,6 +2,7 @@
 
 namespace Illuminate\Http\Resources\JsonApi\Concerns;
 
+use Generator;
 use Illuminate\Contracts\Support\Arrayable;
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\Relations\AsPivot;
@@ -16,9 +17,9 @@
 use Illuminate\Http\Resources\MissingValue;
 use Illuminate\Support\Arr;
 use Illuminate\Support\Collection;
+use Illuminate\Support\LazyCollection;
 use Illuminate\Support\Str;
 use JsonSerializable;
-use WeakMap;
 
 trait ResolvesJsonApiElements
 {
@@ -35,9 +36,9 @@ trait ResolvesJsonApiElements
     /**
      * Cached loaded relationships map.
      *
-     * @var \WeakMap|null
+     * @var array<int, array{0: \Illuminate\Http\Resources\JsonApi\JsonApiResource, 1: string, 2: string, 3: bool}|null
      */
-    protected $loadedRelationshipsMap;
+    public $loadedRelationshipsMap;
 
     /**
      * Cached loaded relationships identifers.
@@ -104,7 +105,7 @@ protected function resolveResourceObject(JsonApiRequest $request): array
      *
      * @throws ResourceIdentificationException
      */
-    protected function resolveResourceIdentifier(JsonApiRequest $request): string
+    public function resolveResourceIdentifier(JsonApiRequest $request): string
     {
         if (! is_null($resourceId = $this->toId($request))) {
             return $resourceId;
@@ -123,7 +124,7 @@ protected function resolveResourceIdentifier(JsonApiRequest $request): string
      *
      * @throws ResourceIdentificationException
      */
-    protected function resolveResourceType(JsonApiRequest $request): string
+    public function resolveResourceType(JsonApiRequest $request): string
     {
         if (! is_null($resourceType = $this->toType($request))) {
             return $resourceType;
@@ -195,7 +196,7 @@ protected function resolveResourceRelationshipIdentifiers(JsonApiRequest $reques
      */
     protected function compileResourceRelationships(JsonApiRequest $request): void
     {
-        if ($this->loadedRelationshipsMap instanceof WeakMap) {
+        if (! is_null($this->loadedRelationshipsMap)) {
             return;
         }
 
@@ -205,74 +206,124 @@ protected function compileResourceRelationships(JsonApiRequest $request): void
         };
 
         $resourceRelationships = (new Collection($this->toRelationships($request)))
-            ->mapWithKeys(function ($value, $key) {
-                $relationResolver = is_int($key) ? new RelationResolver($value) : new RelationResolver($key, $value);
-
-                return [$relationResolver->relationName => $relationResolver];
-            })->filter(fn ($value, $key) => in_array($key, $sparseIncluded));
+            ->transform(fn ($value, $key) => is_int($key) ? new RelationResolver($value) : new RelationResolver($key, $value))
+            ->mapWithKeys(fn ($relationResolver) => [$relationResolver->relationName => $relationResolver])
+            ->filter(fn ($value, $key) => in_array($key, $sparseIncluded));
 
         $resourceRelationshipKeys = $resourceRelationships->keys();
 
         $this->resource->loadMissing($resourceRelationshipKeys->all() ?? []);
 
-        $this->loadedRelationshipsMap = new WeakMap;
+        $this->loadedRelationshipsMap = [];
 
-        $this->loadedRelationshipIdentifiers = $resourceRelationships->mapWithKeys(function (RelationResolver $relationResolver, $key) use ($request) {
-            $relatedModels = $relationResolver->handle($this->resource);
-            $relatedResourceClass = $relationResolver->resourceClass();
+        $this->loadedRelationshipIdentifiers = (new LazyCollection(function () use ($request, $resourceRelationships) {
+            foreach ($resourceRelationships as $relationName => $relationResolver) {
+                $relatedModels = $relationResolver->handle($this->resource);
+                $relatedResourceClass = $relationResolver->resourceClass();
 
-            if (! is_null($relatedModels)) {
-                $relatedModels->loadMissing($request->sparseIncluded($key));
-            }
+                if (! is_null($relatedModels)) {
+                    $relatedModels->loadMissing($request->sparseIncluded($relationName));
+                }
 
-            // Relationship is a collection of models...
-            if ($relatedModels instanceof Collection) {
-                $relatedModels = $relatedModels->values();
+                yield from $this->compileResourceRelationshipUsingResolver(
+                    $this->resource,
+                    $relationResolver,
+                    $relatedModels,
+                    $request
+                );
+            }
+        }))->all();
+    }
 
-                if ($relatedModels->isEmpty()) {
-                    return [$key => ['data' => $relatedModels]];
-                }
+    /**
+     * Compile resource relations.
+     */
+    protected function compileResourceRelationshipUsingResolver(
+        mixed $resource,
+        RelationResolver $relationResolver,
+        Collection|Model|null $relatedModels,
+        JsonApiRequest $request
+    ): Generator {
+        $relationName = $relationResolver->relationName;
+        $resourceClass = $relationResolver->resourceClass();
+
+        // Relationship is a collection of models...
+        if ($relatedModels instanceof Collection) {
+            $relatedModels = $relatedModels->values();
+
+            if ($relatedModels->isEmpty()) {
+                yield $relationName => ['data' => $relatedModels];
+
+                return;
+            }
 
-                $relationship = $this->resource->{$key}();
+            $relationship = $resource->{$relationName}();
+            $isUnique = ! $relationship instanceof BelongsToMany;
 
-                $isUnique = ! $relationship instanceof BelongsToMany;
+            yield $relationName => ['data' => $relatedModels->map(function ($relatedModel) use ($request, $resourceClass, $isUnique) {
+                $relatedResource = rescue(fn () => $relatedModel->toResource($resourceClass), new JsonApiResource($relatedModel));
 
-                $key = $relationResolver->resourceType($relatedModels, $request);
+                return transform(
+                    [$relatedResource->resolveResourceType($request), $relatedResource->resolveResourceIdentifier($request)],
+                    function ($uniqueKey) use ($request, $relatedModel, $relatedResource, $isUnique) {
+                        $this->loadedRelationshipsMap[] = [$relatedResource, ...$uniqueKey, $isUnique];
 
-                return [$key => ['data' => $relatedModels->map(function ($relation) use ($key, $relatedResourceClass, $isUnique) {
-                    return transform([$key, static::resourceIdFromModel($relation)], function ($uniqueKey) use ($relation, $relatedResourceClass, $isUnique) {
-                        $this->loadedRelationshipsMap[$relation] = [...$uniqueKey, $relatedResourceClass, $isUnique];
+                        $this->compileIncludedNestedRelationshipsMap($relatedModel, $relatedResource, $request);
 
                         return [
                             'id' => $uniqueKey[1],
                             'type' => $uniqueKey[0],
                         ];
-                    });
-                })]];
-            }
+                    }
+                );
+            })->all()];
 
-            // Relationship is a single model...
-            $relatedModel = $relatedModels;
+            return;
+        }
 
-            if (is_null($relatedModel)) {
-                return [$key => null];
-            } elseif ($relatedModel instanceof Pivot ||
-                in_array(AsPivot::class, class_uses_recursive($relatedModel), true)) {
-                return [$key => new MissingValue];
-            }
+        // Relationship is a single model...
+        $relatedModel = $relatedModels;
 
-            return [$key => ['data' => transform(
-                [$relationResolver->resourceType($relatedModel, $request), static::resourceIdFromModel($relatedModel)],
-                function ($uniqueKey) use ($relatedModel, $relatedResourceClass) {
-                    $this->loadedRelationshipsMap[$relatedModel] = [...$uniqueKey, $relatedResourceClass, true];
+        if (is_null($relatedModel)) {
+            yield $relationName => null;
 
-                    return [
-                        'id' => $uniqueKey[1],
-                        'type' => $uniqueKey[0],
-                    ];
-                }
-            )]];
-        })->all();
+            return;
+        } elseif ($relatedModel instanceof Pivot ||
+            in_array(AsPivot::class, class_uses_recursive($relatedModel), true)) {
+            yield $relationName => new MissingValue;
+
+            return;
+        }
+
+        $relatedResource = rescue(fn () => $relatedModel->toResource($resourceClass), new JsonApiResource($relatedModel));
+
+        yield $relationName => ['data' => transform(
+            [$relatedResource->resolveResourceType($request), $relatedResource->resolveResourceIdentifier($request)],
+            function ($uniqueKey) use ($relatedModel, $relatedResource, $request) {
+                $this->loadedRelationshipsMap[] = [$relatedResource, ...$uniqueKey, true];
+
+                $this->compileIncludedNestedRelationshipsMap($relatedModel, $relatedResource, $request);
+
+                return [
+                    'id' => $uniqueKey[1],
+                    'type' => $uniqueKey[0],
+                ];
+            }
+        )];
+    }
+
+    /**
+     * Compile included relationships map.
+     */
+    protected function compileIncludedNestedRelationshipsMap(Model $relation, JsonApiResource $resource, JsonApiRequest $request): void
+    {
+        (new Collection($resource->toRelationships($request)))
+            ->transform(fn ($value, $key) => is_int($key) ? new RelationResolver($value) : new RelationResolver($key, $value))
+            ->mapWithKeys(fn ($relationResolver) => [$relationResolver->relationName => $relationResolver])
+            ->filter(fn ($value, $key) => in_array($key, array_keys($relation->getRelations())))
+            ->each(function ($relationResolver, $key) use ($relation, $request) {
+                $this->compileResourceRelationshipUsingResolver($relation, $relationResolver, $relation->getRelation($key), $request);
+            });
     }
 
     /**
@@ -288,10 +339,10 @@ public function resolveIncludedResources(JsonApiRequest $request): array
 
         $relations = new Collection;
 
-        foreach ($this->loadedRelationshipsMap as $relation => $value) {
-            [$type, $id, $relatedResourceClass, $isUnique] = $value;
+        $index = 0;
 
-            $resourceInstance = rescue(fn () => $relation->toResource($relatedResourceClass), new JsonApiResource($relation), false);
+        while ($index < count($this->loadedRelationshipsMap)) {
+            [$resourceInstance, $type, $id, $isUnique] = $this->loadedRelationshipsMap[$index];
 
             if (! $resourceInstance instanceof JsonApiResource &&
                 $resourceInstance instanceof JsonResource) {
@@ -300,6 +351,8 @@ public function resolveIncludedResources(JsonApiRequest $request): array
 
             $relationsData = $resourceInstance->withoutRequestQueryString()->withIncludedFromLoadedRelationships()->resolve($request);
 
+            array_push($this->loadedRelationshipsMap, ...$resourceInstance->loadedRelationshipsMap);
+
             $relations->push(array_filter([
                 'id' => $id,
                 'type' => $type,
@@ -309,6 +362,8 @@ public function resolveIncludedResources(JsonApiRequest $request): array
                 'links' => Arr::get($relationsData, 'data.links'),
                 'meta' => Arr::get($relationsData, 'data.meta'),
             ]));
+
+            $index++;
         }
 
         return $relations->uniqueStrict(fn ($relation) => $relation['_uniqueKey'])
diff --git a/tests/Integration/Http/Resources/JsonApi/JsonApiResourceTest.php b/tests/Integration/Http/Resources/JsonApi/JsonApiResourceTest.php
index e020455e6c19..ced43913ead6 100644
--- a/tests/Integration/Http/Resources/JsonApi/JsonApiResourceTest.php
+++ b/tests/Integration/Http/Resources/JsonApi/JsonApiResourceTest.php
@@ -267,6 +267,7 @@ public function test_it_can_resolve_relationship_with_nested_relationship()
 
         $this->getJson("/posts/{$post1->getKey()}?".http_build_query(['include' => 'author,comments.commenter']))
             ->assertHeader('Content-type', 'application/vnd.api+json')
+            ->dump()
             ->assertExactJson([
                 'data' => [
                     'attributes' => [
@@ -313,6 +314,14 @@ public function test_it_can_resolve_relationship_with_nested_relationship()
                             ],
                         ],
                     ],
+                    [
+                        'attributes' => [
+                            'email' => $user->email,
+                            'name' => $user->name,
+                        ],
+                        'id' => (string) $user->getKey(),
+                        'type' => 'users',
+                    ],
                 ],
             ])
             ->assertJsonMissing(['jsonapi']);

From 5b3eef7b7538f275e2dae349088fff167e1d3c3a Mon Sep 17 00:00:00 2001
From: Mior Muhammad Zaki <crynobone@gmail.com>
Date: Fri, 5 Dec 2025 10:18:43 +0800
Subject: [PATCH 46/48] Remove dump from JsonApiResourceTest

Removed debug dump from JSON API resource test.
---
 tests/Integration/Http/Resources/JsonApi/JsonApiResourceTest.php | 1 -
 1 file changed, 1 deletion(-)

diff --git a/tests/Integration/Http/Resources/JsonApi/JsonApiResourceTest.php b/tests/Integration/Http/Resources/JsonApi/JsonApiResourceTest.php
index ced43913ead6..82909d11ffdc 100644
--- a/tests/Integration/Http/Resources/JsonApi/JsonApiResourceTest.php
+++ b/tests/Integration/Http/Resources/JsonApi/JsonApiResourceTest.php
@@ -267,7 +267,6 @@ public function test_it_can_resolve_relationship_with_nested_relationship()
 
         $this->getJson("/posts/{$post1->getKey()}?".http_build_query(['include' => 'author,comments.commenter']))
             ->assertHeader('Content-type', 'application/vnd.api+json')
-            ->dump()
             ->assertExactJson([
                 'data' => [
                     'attributes' => [

From 4a0c6cd79ba655f0db0fa5e3b74a42894973f0ce Mon Sep 17 00:00:00 2001
From: Taylor Otwell <taylor@laravel.com>
Date: Tue, 9 Dec 2025 13:07:27 -0600
Subject: [PATCH 47/48] formatting

---
 .../Concerns/ResolvesJsonApiElements.php      | 92 ++++++++++---------
 .../Resources/JsonApi/RelationResolver.php    | 26 +-----
 2 files changed, 49 insertions(+), 69 deletions(-)

diff --git a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
index e0efca7271b7..e199c64ca680 100644
--- a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
+++ b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
@@ -24,14 +24,14 @@
 trait ResolvesJsonApiElements
 {
     /**
-     * Determine whether resource use included and fields from the request object.
+     * Determine whether resources respect inclusions and fields from the request.
      */
     protected bool $usesRequestQueryString = true;
 
     /**
      * Determine whether included relationship for the resource from eager loaded relationship.
      */
-    protected bool $usesIncludedFromLoadedRelationships = false;
+    protected bool $includesPreviouslyLoadedRelationships = false;
 
     /**
      * Cached loaded relationships map.
@@ -45,40 +45,6 @@ trait ResolvesJsonApiElements
      */
     protected array $loadedRelationshipIdentifiers = [];
 
-    /**
-     * Determine relationships should rely on request's query string.
-     *
-     * @return $this
-     */
-    public function withRequestQueryString(bool $value = true)
-    {
-        $this->usesRequestQueryString = $value;
-
-        return $this;
-    }
-
-    /**
-     * Determine relationships should not be relied on request's query string.
-     *
-     * @return $this
-     */
-    public function withoutRequestQueryString()
-    {
-        return $this->withRequestQueryString(false);
-    }
-
-    /**
-     * Determine relationship should include loaded relationships.
-     *
-     * @return $this
-     */
-    public function withIncludedFromLoadedRelationships()
-    {
-        $this->usesIncludedFromLoadedRelationships = true;
-
-        return $this;
-    }
-
     /**
      * Resolves `data` for the resource.
      */
@@ -201,7 +167,7 @@ protected function compileResourceRelationships(JsonApiRequest $request): void
         }
 
         $sparseIncluded = match (true) {
-            $this->usesIncludedFromLoadedRelationships => array_keys($this->resource->getRelations()),
+            $this->includesPreviouslyLoadedRelationships => array_keys($this->resource->getRelations()),
             default => $request->sparseIncluded(),
         };
 
@@ -226,10 +192,10 @@ protected function compileResourceRelationships(JsonApiRequest $request): void
                 }
 
                 yield from $this->compileResourceRelationshipUsingResolver(
+                    $request,
                     $this->resource,
                     $relationResolver,
                     $relatedModels,
-                    $request
                 );
             }
         }))->all();
@@ -240,9 +206,9 @@ protected function compileResourceRelationships(JsonApiRequest $request): void
      */
     protected function compileResourceRelationshipUsingResolver(
         mixed $resource,
+        JsonApiRequest $request,
         RelationResolver $relationResolver,
-        Collection|Model|null $relatedModels,
-        JsonApiRequest $request
+        Collection|Model|null $relatedModels
     ): Generator {
         $relationName = $relationResolver->relationName;
         $resourceClass = $relationResolver->resourceClass();
@@ -258,6 +224,7 @@ protected function compileResourceRelationshipUsingResolver(
             }
 
             $relationship = $resource->{$relationName}();
+
             $isUnique = ! $relationship instanceof BelongsToMany;
 
             yield $relationName => ['data' => $relatedModels->map(function ($relatedModel) use ($request, $resourceClass, $isUnique) {
@@ -268,7 +235,7 @@ protected function compileResourceRelationshipUsingResolver(
                     function ($uniqueKey) use ($request, $relatedModel, $relatedResource, $isUnique) {
                         $this->loadedRelationshipsMap[] = [$relatedResource, ...$uniqueKey, $isUnique];
 
-                        $this->compileIncludedNestedRelationshipsMap($relatedModel, $relatedResource, $request);
+                        $this->compileIncludedNestedRelationshipsMap($request, $relatedModel, $relatedResource);
 
                         return [
                             'id' => $uniqueKey[1],
@@ -302,7 +269,7 @@ function ($uniqueKey) use ($request, $relatedModel, $relatedResource, $isUnique)
             function ($uniqueKey) use ($relatedModel, $relatedResource, $request) {
                 $this->loadedRelationshipsMap[] = [$relatedResource, ...$uniqueKey, true];
 
-                $this->compileIncludedNestedRelationshipsMap($relatedModel, $relatedResource, $request);
+                $this->compileIncludedNestedRelationshipsMap($request, $relatedModel, $relatedResource);
 
                 return [
                     'id' => $uniqueKey[1],
@@ -315,7 +282,7 @@ function ($uniqueKey) use ($relatedModel, $relatedResource, $request) {
     /**
      * Compile included relationships map.
      */
-    protected function compileIncludedNestedRelationshipsMap(Model $relation, JsonApiResource $resource, JsonApiRequest $request): void
+    protected function compileIncludedNestedRelationshipsMap(JsonApiRequest $request, Model $relation, JsonApiResource $resource): void
     {
         (new Collection($resource->toRelationships($request)))
             ->transform(fn ($value, $key) => is_int($key) ? new RelationResolver($value) : new RelationResolver($key, $value))
@@ -349,7 +316,10 @@ public function resolveIncludedResources(JsonApiRequest $request): array
                 $resourceInstance = new JsonApiResource($resourceInstance->resource);
             }
 
-            $relationsData = $resourceInstance->withoutRequestQueryString()->withIncludedFromLoadedRelationships()->resolve($request);
+            $relationsData = $resourceInstance
+                ->withoutRequestQueryString()
+                ->includePreviouslyLoadedRelationships()
+                ->resolve($request);
 
             array_push($this->loadedRelationshipsMap, ...$resourceInstance->loadedRelationshipsMap);
 
@@ -413,6 +383,40 @@ public static function resourceTypeFromModel(Model $model): string
         );
     }
 
+    /**
+     * Indicate that relationship loading should respect the request's "includes" query string.
+     *
+     * @return $this
+     */
+    public function withRequestQueryString(bool $value = true)
+    {
+        $this->usesRequestQueryString = $value;
+
+        return $this;
+    }
+
+    /**
+     * Indicate that relationship loading should not rely on the request's "includes" query string.
+     *
+     * @return $this
+     */
+    public function withoutRequestQueryString()
+    {
+        return $this->withRequestQueryString(false);
+    }
+
+    /**
+     * Determine relationship should include loaded relationships.
+     *
+     * @return $this
+     */
+    public function includePreviouslyLoadedRelationships()
+    {
+        $this->includesPreviouslyLoadedRelationships = true;
+
+        return $this;
+    }
+
     /**
      * Normalize the resource type.
      */
diff --git a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
index 94b97dd41814..772acff826a9 100644
--- a/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
+++ b/src/Illuminate/Http/Resources/JsonApi/RelationResolver.php
@@ -5,7 +5,6 @@
 use Closure;
 use Illuminate\Database\Eloquent\Collection;
 use Illuminate\Database\Eloquent\Model;
-use Illuminate\Http\Resources\JsonApi\Exceptions\ResourceIdentificationException;
 
 /**
  * @internal
@@ -44,7 +43,7 @@ public function __construct(public string $relationName, Closure|string|null $re
     }
 
     /**
-     * Resolve relation for a resource.
+     * Resolve the relation for a resource.
      */
     public function handle(mixed $resource): Collection|Model|null
     {
@@ -60,27 +59,4 @@ public function resourceClass(): ?string
     {
         return $this->relationResourceClass;
     }
-
-    /**
-     * Get the relation resource type.
-     *
-     * @throws \Illuminate\Http\Resources\JsonApi\Exceptions\ResourceIdentificationException
-     */
-    public function resourceType(Collection|Model $resources, JsonApiRequest $request): ?string
-    {
-        $resource = $resources instanceof Collection ? $resources->first() : $resources;
-
-        if (is_null($resourceClass = $this->resourceClass())) {
-            return JsonApiResource::resourceTypeFromModel($resource);
-        }
-
-        $relatedResource = new $resourceClass($resource);
-
-        return tap($relatedResource->toType($request), function ($resourceType) use ($relatedResource) {
-            throw_if(
-                is_null($resourceType),
-                ResourceIdentificationException::attemptingToDetermineTypeFor($relatedResource)
-            );
-        });
-    }
 }

From 4e318f3f90eb1a325cae32dac5cdf9d45b94c3a1 Mon Sep 17 00:00:00 2001
From: Taylor Otwell <taylor@laravel.com>
Date: Tue, 9 Dec 2025 13:08:52 -0600
Subject: [PATCH 48/48] formatting

---
 .../Resources/JsonApi/Concerns/ResolvesJsonApiElements.php    | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
index e199c64ca680..1ea9188f7792 100644
--- a/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
+++ b/src/Illuminate/Http/Resources/JsonApi/Concerns/ResolvesJsonApiElements.php
@@ -205,8 +205,8 @@ protected function compileResourceRelationships(JsonApiRequest $request): void
      * Compile resource relations.
      */
     protected function compileResourceRelationshipUsingResolver(
-        mixed $resource,
         JsonApiRequest $request,
+        mixed $resource,
         RelationResolver $relationResolver,
         Collection|Model|null $relatedModels
     ): Generator {
@@ -289,7 +289,7 @@ protected function compileIncludedNestedRelationshipsMap(JsonApiRequest $request
             ->mapWithKeys(fn ($relationResolver) => [$relationResolver->relationName => $relationResolver])
             ->filter(fn ($value, $key) => in_array($key, array_keys($relation->getRelations())))
             ->each(function ($relationResolver, $key) use ($relation, $request) {
-                $this->compileResourceRelationshipUsingResolver($relation, $relationResolver, $relation->getRelation($key), $request);
+                $this->compileResourceRelationshipUsingResolver($request, $relation, $relationResolver, $relation->getRelation($key));
             });
     }