Nestjs - 导入服务未被其他服务识别

Posted 2023-03-10

【中文标题】Nestjs - 导入服务未被其他服务识别

【英文标题】：Nest.js - Imported service not recognized by another service

【发布时间】：2020-04-29 19:43:01

【问题描述】：

我正在尝试在另一个服务（订单）类中重用服务（库存），就像这样

order.module.ts

import  InventoryModule  from '../inventory/inventory.module';

@Module(
  imports: [TypeOrmModule.forFeature([OrderEntity]), InventoryModule],
  controllers: [OrderController],
  providers: [OrderService],
)
export class OrderModule 

然后像这样在OrderService 中使用InventoryService 方法

@Injectable()
export class OrderService 
    constructor(
        @InjectRepository(OrderEntity) private orderRepository: Repository<OrderEntity>,
        private inventoryService: InventoryService) 

    /**
     * Add order item
     * @param data Object
     */
    async add(data: OrderDTO) 
        const  inventory_item_id  = data
        const inventoryItem = await this.inventoryService.getOne(inventory_item_id)

        if (inventoryItem.quantity_available <= 0) 
            throw new Error('Cannot add item to order, insufficient quantities!')
        

        const orderItem = await this.orderRepository.create(data)

        if (orderItem) 
            const updatedInventoryItemQuantity = inventoryItem.quantity_available - 1
            const updatedInventoryItem = await this.inventoryService.edit(inventory_item_id, 
                quantity_available: updatedInventoryItemQuantity,
            )

        
        await this.orderRepository.save(orderItem)
        return orderItem
    

但我得到以下堆栈跟踪：

Require stack:
- /Users/jred/workspace/projects/my-proj/dist/order/order.service.js
- /Users/jred/workspace/projects/my-proj/dist/order/order.controller.js
- /Users/jred/workspace/projects/my-proj/dist/order/order.module.js
- /Users/jred/workspace/projects/my-proj/dist/app.module.js
- /Users/jred/workspace/projects/my-proj/dist/main.js
    at Function.Module._resolveFilename (internal/modules/cjs/loader.js:623:15)
    at Function.Module._load (internal/modules/cjs/loader.js:527:27)
    at Module.require (internal/modules/cjs/loader.js:681:19)
    at require (internal/modules/cjs/helpers.js:16:16)
    at Object.<anonymous> (/Users/jred/workspace/projects/my-proj/dist/order/order.service.js:19:29)
    at Module._compile (internal/modules/cjs/loader.js:774:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:785:10)
    at Module.load (internal/modules/cjs/loader.js:641:32)
    at Function.Module._load (internal/modules/cjs/loader.js:556:12)
    at Module.require (internal/modules/cjs/loader.js:681:19) 
  code: 'MODULE_NOT_FOUND',
  requireStack: [
    '/Users/jred/workspace/projects/my-proj/dist/order/order.service.js',
    '/Users/jred/workspace/projects/my-proj/dist/order/order.controller.js',
    '/Users/jred/workspace/projects/my-proj/dist/order/order.module.js',
    '/Users/jred/workspace/projects/my-proj/dist/app.module.js',
    '/Users/jred/workspace/projects/my-proj/dist/main.js'
  ]

有人经历过吗？在另一个模块中调用导入服务的正确方法是什么？

【问题讨论】：

您是否从其模块中导出InventoryService？

您遇到的是特定于 Nest 的错误，还是特定于 javascript 的错误？如果是 Nest 特定的，您收到的错误消息是什么？

这能解决您的问题吗？ ***.com/a/51821523/4694994

【参考方案1】：

问题出在我的 Order.service.ts 文件中，使用自动导入语法

此导入包含src

import InventoryService from 'src/inventory/inventory.service';

不得不改成这个

import InventoryService from '../inventory/inventory.service';

【参考方案2】：

检查您的 app.module.ts。

确保您在导入数组中添加了 InventoryModule。

此外，请确保您正在从 InventoryModule 导出 InventoryService。

// app.module.ts
@Module(
    imports: [InventoryModule, ...othermodules],
    exports: [],
    providers: []
)
export class ApplicationModule 

// inventory.module.ts
@Module(
    imports: [...yourModules],
    exports: [InventoryService],
    providers: [InventoryService]
)
export class InventoryModule