We could add a validation/matching step that would exclude overlapping routes. I like it!

This is an expressjs issue, routes RouterProxy will still receive 2 requests. If you do this, then you will have to change all the logic of routes. Without using expressjs middlware.

example in expressjs

var express = require('express');
var app = express();

app.use('/user/test', function (req, res, next) {
  console.log('test method');
  next();
});
app.use('/user/:id', function (req, res, next) {
  console.log('id method');
  next();
});

app.get('/user/:id', function (req, res, next) {
  res.send('USER');
});

app.listen(3000)

curl http://localhost:3000/user/test return:

test method
id method

I'm aware of the router behavior in express, but this problem is not particularly about this.

Can you please tell me where it's at? Where do you want me to look?

hi
could i modify routeInfo when it use controller at forRoutes?

// as is 
[
  {
     path: '/cats/test',
     method: RequestMethod.GET,
  },
  {
     path: '/cats/:id',
     method: RequestMethod.GET,
  },
]

/* to be, it is like when it use '/cats' at forRoutes*/
[
  {
     path: '/cats',
     method: RequestMethod.ALL,
  }
]

@Injectable()
export class LoggerMiddleware implements NestMiddleware {
  resolve(context: string): MiddlewareFunction {
    return (req, res, next) => {
      Logger.log(req.route.path, 'MIDDLEWARE');
      next();
    };
  }
}

// app module
export class AppModule implements NestModule {
  configure(consumer: MiddlewareConsumer) {
    consumer.apply(LoggerMiddleware).forRoutes('/cats')
                    .apply(LoggerMiddleware).forRoutes('/cats');
  }
}

Current behavior

Use same Middleware for same route, the Middleware run twice.

Expected behavior

I think it should run once，because the same Middleware do same things, it is waste of performance run reapeat.

@underfin you applied it twice, so it runs twice.

I have a try for this issue Middleware runs for every matching route .You suggest it for this validation/matching step that would exclude overlapping routes.
I think the Middleware only run once for one same request.such as we dont do some validation/matching step,because it is complex.But I have a other issues for Use same Middleware for same route, the Middleware run twice.
The below is my code.I want to get your some suggetion for this.
packages/core/middleware/middleware-module.ts#260

 const middleware = (req, res, next) => {
      const stack: Set<NestMiddleware> = req.stack || new Set();
        if(!stack.has(instance)){
          stack.add(instance);
          req.stack = stack;
          instance.use.apply(instance, [req, res, next]);
        } else {
          next();
        }
    };

@underfin Do you have an update? I am happy to work on this.

I pull a pr #3187.If you hava an better idea.Just do it.

No worries, will find another :)