From ce3c62659d3f1c37da053d5fdf0ab9f17ee8d9f3 Mon Sep 17 00:00:00 2001
From: Ash Allen <mail@ashallendesign.co.uk>
Date: Wed, 20 Nov 2024 22:28:23 +0000
Subject: [PATCH 1/2] Added `for` method to Eloquent models.

---
 src/Illuminate/Database/Eloquent/Model.php   | 18 ++++++++
 tests/Database/DatabaseEloquentModelTest.php | 48 ++++++++++++++++++++
 2 files changed, 66 insertions(+)

diff --git a/src/Illuminate/Database/Eloquent/Model.php b/src/Illuminate/Database/Eloquent/Model.php
index 7afa59933416..9eb6936e7374 100644
--- a/src/Illuminate/Database/Eloquent/Model.php
+++ b/src/Illuminate/Database/Eloquent/Model.php
@@ -577,6 +577,24 @@ public function forceFill(array $attributes)
         return static::unguarded(fn () => $this->fill($attributes));
     }
 
+    /**
+     * Set the foreign key for a relationship to another model.
+     *
+     * @param  \Illuminate\Database\Eloquent\Model  $model
+     * @param  string|null  $relationship
+     * @return $this
+     */
+    public function for($model, $relationship = null)
+    {
+        $relationship ??= Str::camel(class_basename($model));
+
+        $foreignKey = $this->{$relationship}()->getForeignKeyName();
+
+        $this->forceFill([$foreignKey => $model->getKey()]);
+
+        return $this;
+    }
+
     /**
      * Qualify the given column name by the model's table.
      *
diff --git a/tests/Database/DatabaseEloquentModelTest.php b/tests/Database/DatabaseEloquentModelTest.php
index e7f249512bbd..091f5cf3197c 100755
--- a/tests/Database/DatabaseEloquentModelTest.php
+++ b/tests/Database/DatabaseEloquentModelTest.php
@@ -3178,6 +3178,29 @@ public function testCollectedByAttribute()
 
         $this->assertInstanceOf(CustomEloquentCollection::class, $collection);
     }
+
+    public function testForCanSetForeignKeysForRelationships()
+    {
+        $post = new Post();
+        $post->id = 123;
+
+        $user = new User();
+        $user->id = 456;
+
+        $comment = (new Comment());
+        $this->addMockConnection($comment);
+
+        // Set some data so we can make sure "for" isn't clearing it.
+        $comment->content = 'Hello';
+
+        $comment
+            ->for($post, 'blogPost')
+            ->for($user);
+
+        $this->assertSame($comment->content, 'Hello');
+        $this->assertSame($comment->the_post_id, 123);
+        $this->assertSame($comment->user_id, 456);
+    }
 }
 
 class EloquentTestObserverStub
@@ -3946,3 +3969,28 @@ class EloquentModelWithCollectedByAttribute extends Model
 class CustomEloquentCollection extends Collection
 {
 }
+
+class User extends Model
+{
+    protected $guarded = [];
+}
+
+class Post extends Model
+{
+    protected $guarded = [];
+}
+
+class Comment extends Model
+{
+    protected $guarded = [];
+
+    public function blogPost(): BelongsTo
+    {
+        return $this->belongsTo(Post::class, 'the_post_id');
+    }
+
+    public function user(): BelongsTo
+    {
+        return $this->belongsTo(User::class);
+    }
+}

From 9b67d74eb5eb09564b762573d785695d107e12d9 Mon Sep 17 00:00:00 2001
From: Ash Allen <mail@ashallendesign.co.uk>
Date: Wed, 20 Nov 2024 22:53:18 +0000
Subject: [PATCH 2/2] Fixed failing test.

---
 tests/Database/DatabaseEloquentModelTest.php | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/tests/Database/DatabaseEloquentModelTest.php b/tests/Database/DatabaseEloquentModelTest.php
index 091f5cf3197c..070b40359a51 100755
--- a/tests/Database/DatabaseEloquentModelTest.php
+++ b/tests/Database/DatabaseEloquentModelTest.php
@@ -3184,7 +3184,7 @@ public function testForCanSetForeignKeysForRelationships()
         $post = new Post();
         $post->id = 123;
 
-        $user = new User();
+        $user = new DatabaseEloquentModelTestUser();
         $user->id = 456;
 
         $comment = (new Comment());
@@ -3194,12 +3194,12 @@ public function testForCanSetForeignKeysForRelationships()
         $comment->content = 'Hello';
 
         $comment
-            ->for($post, 'blogPost')
-            ->for($user);
+            ->for($post)
+            ->for($user, 'user');
 
         $this->assertSame($comment->content, 'Hello');
-        $this->assertSame($comment->the_post_id, 123);
-        $this->assertSame($comment->user_id, 456);
+        $this->assertSame($comment->post_id, 123);
+        $this->assertSame($comment->the_user_id, 456);
     }
 }
 
@@ -3970,7 +3970,7 @@ class CustomEloquentCollection extends Collection
 {
 }
 
-class User extends Model
+class DatabaseEloquentModelTestUser extends Model
 {
     protected $guarded = [];
 }
@@ -3984,13 +3984,13 @@ class Comment extends Model
 {
     protected $guarded = [];
 
-    public function blogPost(): BelongsTo
+    public function post(): BelongsTo
     {
-        return $this->belongsTo(Post::class, 'the_post_id');
+        return $this->belongsTo(Post::class);
     }
 
     public function user(): BelongsTo
     {
-        return $this->belongsTo(User::class);
+        return $this->belongsTo(DatabaseEloquentModelTestUser::class, 'the_user_id');
     }
 }