如何在没有负载的方法中添加nestjs-asyncapi注释？

Question

我正在使用

nestjs-asyncapi

构建 API 文档。目前，API 已为包含主体 (DTO) 的端点正确生成并正确注释。但是，如果我为没有主体的方法添加

@AsyncApiSub

注释（带有

payload: null

），我会收到错误：

.../node_modules/@nestjs/swagger/dist/services/schema-object-factory.js:73
        const { prototype } = type;
                ^
TypeError: Cannot destructure property 'prototype' of 'type' as it is null.

以下是生成此类错误的代码示例：

...
import { AsyncApiSub } from 'nestjs-asyncapi';

@WebSocketGateway()
export class ActivityGateway {
    constructor(
        private activityService: ActivityService,
    ) {}
    @SubscribeMessage(ActivityActions.ADD_ACTIVITY)
    @AsyncApiSub({
        channel: ActivityActions.ADD_ACTIVITY,
        message: {
            payload: CreateActivityTemplateDto,
        },
    })
    public async addActivity(
        @ConnectedSocket() socket: ClientSocket,
        @MessageBody() body: CreateActivityTemplateDto,
    ): Promise<ActivitySettings> {
        return this.activityService.createNewActivityTemplate(socket.userId, body);
    }

    @SubscribeMessage(ActivityActions.GENERATE_DEMO_ACTIVITY)
    @AsyncApiSub({ channel: ActivityActions.GENERATE_DEMO_ACTIVITY, message: { payload: null } })
    public async generateDemoActivity(@ConnectedSocket() socket: ClientSocket): Promise<Activity[]> {
        return this.activityService.generateDemoActivity(socket.userId);
    }
}

如何将操作

ActivityActions.GENERATE_DEMO_ACTIVITY

添加到我的 API 文档中？

您尝试了什么以及您期待什么？

我尝试添加带有空负载的

AsyncApiSub

注释：

@AsyncApiSub({ channel: ActivityActions.GENERATE_DEMO_ACTIVITY, message: { payload: null } })

我还尝试添加空注释

AsyncApiSub()

。
我希望看到我的 API 文档中列出的操作

ActivityActions.GENERATE_DEMO_ACTIVITY

。

Answer 1

要解决此问题，您应该提供有效的有效负载类型，即使它是空类型或没有属性的对象。

以下是修改代码的方法：

创建空 DTO：定义一个空 DTO 类，可以表示空负载。这是一个占位符，不会影响实际功能。

export class EmptyDto {}

更新@AsyncApiSub注解：在payload字段中使用这个EmptyDto而不是null

@SubscribeMessage(ActivityActions.GENERATE_DEMO_ACTIVITY)
@AsyncApiSub({
    channel: ActivityActions.GENERATE_DEMO_ACTIVITY,
    message: { payload: EmptyDto },  // Use the EmptyDto class
})
public async generateDemoActivity(@ConnectedSocket() socket: ClientSocket): Promise<Activity[]> {
    return this.activityService.generateDemoActivity(socket.userId);
}

完整的类应该如下所示：

    import { AsyncApiSub } from 'nestjs-asyncapi';
    import { SubscribeMessage, WebSocketGateway } from '@nestjs/websockets';
    import { ConnectedSocket, MessageBody } from '@nestjs/websockets';
    import { ClientSocket } from './client-socket.interface'; // adjust as needed
    import { CreateActivityTemplateDto } from './create-activity-template.dto'; // adjust as needed
    import { ActivitySettings } from './activity-settings.dto'; // adjust as needed
    import { Activity } from './activity.dto'; // adjust as needed
    import { ActivityService } from './activity.service'; // adjust as needed
    // Define an empty DTO for cases with no payload
    export class EmptyDto {}
    @WebSocketGateway()
    export class ActivityGateway {
        constructor(
            private activityService: ActivityService,
        ) {}
        @SubscribeMessage(ActivityActions.ADD_ACTIVITY)
        @AsyncApiSub({
            channel: ActivityActions.ADD_ACTIVITY,
            message: {
                payload: CreateActivityTemplateDto,
            },
        })
        public async addActivity(
            @ConnectedSocket() socket: ClientSocket,
            @MessageBody() body: CreateActivityTemplateDto,
        ): Promise<ActivitySettings> {
            return this.activityService.createNewActivityTemplate(socket.userId, body);
        }
        @SubscribeMessage(ActivityActions.GENERATE_DEMO_ACTIVITY)
        @AsyncApiSub({
            channel: ActivityActions.GENERATE_DEMO_ACTIVITY,
            message: { payload: EmptyDto },  // Use the EmptyDto class
        })
        public async generateDemoActivity(@ConnectedSocket() socket: ClientSocket): Promise<Activity[]> {
            return this.activityService.generateDemoActivity(socket.userId);
        }

}

总结 通过使用 EmptyDto 类或类似的占位符，您可以避免将 null 作为有效负载类型传递，这应该可以解决您遇到的错误。这种方法可确保 @AsyncApiSub 装饰器正常工作，并且您的 API 文档可以正确列出 ActivityActions.GENERATE_DEMO_ACTIVITY 操作。