Laravel Testing: Factory States and Relationships

Advanced factory techniques:

Factory States

public function active(): static
{
    return $this->state(fn (array $attributes) => [
        'is_active' => true,
    ]);
}

Create with Relationships

Post::factory()
    ->has(Comment::factory()->count(3))
    ->create();

For Relationships

Comment::factory()
    ->for(Post::factory())
    ->create();

Factories make testing with complex data structures simple.