How to install Express middleware (express-openapi-validator) in NestJS?

I added a NestJS example to express-openapi-validator (static link for posterity).

The AppModule looks basically identical, although you don't need to iterate over the middlewares:

@Module({  imports: [PingModule],  providers: [{ provide: APP_FILTER, useClass: OpenApiExceptionFilter }],})export class AppModule implements NestModule {  configure(consumer: MiddlewareConsumer) {    consumer      .apply(        ...OpenApiValidator.middleware({          apiSpec: join(__dirname, './api.yaml'),        }),      )      .forRoutes('*');  }}

I also added an exception filter to convert the error from express-openapi-validator to a proper response; otherwise I would always get a 500 error. You could also use this approach to convert the error into a custom error format.

import { ArgumentsHost, Catch, ExceptionFilter } from '@nestjs/common';import { Response } from 'express';import { error } from 'express-openapi-validator';@Catch(...Object.values(error))export class OpenApiExceptionFilter implements ExceptionFilter {  catch(error: ValidationError, host: ArgumentsHost) {    const ctx = host.switchToHttp();    const response = ctx.getResponse<Response>();    response.status(error.status).json(error);  }}interface ValidationError {  status: number;  message: string;  errors: Array<{    path: string;    message: string;    error_code?: string;  }>;  path?: string;  name: string;}

I have now got it working:

configure(consumer: MiddlewareConsumer) {    middleware({        apiSpec: `${__dirname}/../api-doc/bff-api.yaml`    }).forEach(value => consumer.apply(value).forRoutes(OrganizationController))}