Laravel透视表工厂报错：Call to a member function __call() on null

错误Call to a member function __call() on null出现在调用OrderProduct::factory()->create()时，核心原因是OrderProduct工厂未正确关联对应模型，或OrderProduct模型未正确创建/配置。

1. 确保OrderProduct模型存在并配置正确 #

在app/Models/目录下创建（或检查）OrderProduct.php，确保填充字段和表名正确：

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class OrderProduct extends Model
{
    // 允许批量赋值的字段
    protected $fillable = ['order_id', 'product_id', 'quantity', 'price'];

    // 如果你的透视表名不是默认的`order_products`（比如是`order_product`），需手动指定
    // protected $table = 'order_product';
}

2. 修复OrderProductFactory的模型绑定 #

打开Database/Factories/OrderProductFactory.php，必须指定对应的模型类：

<?php

namespace Database\Factories;

use App\Models\OrderProduct;
use Illuminate\Database\Eloquent\Factories\Factory;

class OrderProductFactory extends Factory
{
    // 关键：绑定对应的模型
    protected $model = OrderProduct::class;

    public function definition(): array
    {
        return [
            'order_id' => \App\Models\Order::factory(),
            'product_id' => \App\Models\Product::factory(),
            'quantity' => $this->faker->numberBetween(1, 10),
            'price' => $this->faker->randomFloat(2, 5, 100),
        ];
    }
}

3. 确认Order与Product模型的多对多关联配置 #

因为透视表包含额外字段（quantity、price），需要在关联中指定使用OrderProduct模型并声明这些字段：

Order模型： #

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class Order extends Model
{
    // ...其他代码

    public function products()
    {
        return $this->belongsToMany(Product::class)
            ->using(OrderProduct::class)
            ->withPivot('quantity', 'price');
    }
}

Product模型： #

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class Product extends Model
{
    // ...其他代码

    public function orders()
    {
        return $this->belongsToMany(Order::class)
            ->using(OrderProduct::class)
            ->withPivot('quantity', 'price');
    }
}

4. 简化测试代码（可选优化） #

你可以利用Eloquent关联直接创建关联数据，无需手动构造OrderProduct数据：

public function testCalculateOrderTotal(): void
{
    $address = Address::factory()->create();
    $client = Client::factory()->create(['address_id' => $address->id]);
    $order = Order::factory()->create(['client_id' => $client->id]);
    
    // 通过关联创建带额外字段的透视表数据
    $order->products()->attach([
        Product::factory()->create()->id => ['quantity' => 2, 'price' => 100.00],
        Product::factory()->create()->id => ['quantity' => 1, 'price' => 150.00],
    ]);

    $orderProducts = $order->products->map(fn($product) => $product->pivot);

    $this->orderProductRepository
        ->shouldReceive('findByOrder')
        ->with($order->id)
        ->once()
        ->andReturn(collect($orderProducts));

    $expectedTotal = (2 * 100.00) + (1 * 150.00);
    $total = $this->orderProductService->calculateOrderTotal($order->id);

    $this->assertIsFloat($total);
    $this->assertEquals($expectedTotal, $total);
}

做完以上步骤后，重新执行测试命令即可解决报错。

内容的提问来源于stack exchange，提问作者barbgluz