Validator does not work with express router

[SpencerLawrenceBrown]

I am not sure if this is a feature request or a bug, but the validator does not validate requests and responses to/from express routers.

When I originally set up my app, all of my routes lived in the app.ts file and were being validated correctly.

app.ts

const app = express();
app.use(bodyParser.json());
app.use(express.json());

new OpenApiValidator({
  apiSpec: './workflow-tracker-openapi.yml',
  validateRequests: true,
  validateResponses: true,
}).install(app);

// Validates correctly! :)
app.get('/v1/progress/:workflowType', function(req, res, next) {
  res.json([{id: 1, name: 'test'}]);
});

however I am going to have a lot of routes + middlewares and want to use express routers to split them up. So I split my routes to use a router and the validator stopped working:

app.ts

const app = express();
app.use(bodyParser.json());
app.use(express.json());
app.use('/v1', progressRouter);

new OpenApiValidator({
  apiSpec: './workflow-tracker-openapi.yml',
  validateRequests: true,
  validateResponses: true,
}).install(app);

api/progress.ts

const router = express.Router();

// No longer validated :(
router.get('/progress/:workflowType', function(req, res, next) {
  res.json([{id: 1, name: 'test'}]);
});

export { router as progressRouter };

Furthermore I tried to install the routers to the OpenApiValidator but it only accepts Applications.

Am I missed a configuration step or are routers not supported currently? If they are not, is there timeline for when they would be supported?

Is there another workaround for this?

thank you!

[SpencerLawrenceBrown]

Looks like the validator middleware only gets pushed onto the app not the routes:

express-openapi-validator/dist/index.js

        if (this.options.validateRequests)
            use.push(validateMiddleware);
        if (this.options.validateResponses)
            use.push(resOav.validate());
        app.use(use);

I imagine this is the issue.

[SpencerLawrenceBrown]

ok wow, did more digging and it turns out that the order in which the middlewares are added matters
:(

Validates correctly

const app = express();
new OpenApiValidator({
  apiSpec: './workflow-tracker-openapi.yml',
  validateRequests: true,
  validateResponses: true,
}).install(app);
app.use(bodyParser.json());
app.use(express.json());
app.use('/v1', progressRouter);

Does not validate

const app = express();
app.use('/v1', progressRouter);
new OpenApiValidator({
  apiSpec: './workflow-tracker-openapi.yml',
  validateRequests: true,
  validateResponses: true,
}).install(app);
app.use(bodyParser.json());
app.use(express.json());

[SpencerLawrenceBrown]

Let me know if you'd like me to open up a pr to talk about this in the documentation

[cdimascio]

I believe the issue is the fact in the second example (Does not validate), the bodyParser middleware is setup after the routes are setup. To parse json, text, etc the parse middleware should come earlier in the chain

Assuming this is the case, perhaps, a note should be added to the documentation.

Note that I can certainly have the validator install the parser middleware automatically, however I feel the choice of parser should be left to the user and not to the library.

[cdimascio]

@SpencerLawrenceBrown i've added some notes to the doc. feel free to provide feedback. thanks!