Add useOrginalUrl flag

[Mnwa]

Hey! In my project I need to use router mask instead originalUrl param. I will add support it with optional flag.

[joao-fontenele]

I see some problems with this implementation

• if a route doesn't have a handler, it will not enter the middleware, and will therefore not be measured, depending on the application it's important to know if a client is eventually calling a route without a handler
• if the express app uses express.Router the parent routing will not be part of req.path.route, so the metrics will have the wrong label

I agree that req.route.path have a nicer formatting and maybe it should have been the default, but it doesn't seem to work for nested routers.

Opinions or better ideas to handle these cases are welcome

[joao-fontenele]

to exemplify the matter with nested routers here's a minimal snippet

const express = require('express');

const app = express();
const router = new express.Router({ mergeParams: true });

router.get('/nested/:id', (req, res) => {
  console.log('GET /internal/some/:id');
  console.log('req.originalUrl', req.originalUrl); // will log `/parent/nested/1`
  console.log('req.route.path', req.route.path); // will log `/nested/:id`
  res.sendStatus(200);
});

app.use('/parent', router);


const PORT = 9001;
app.listen(PORT, () => {
  console.log(`Example api is listening on http://localhost:${PORT}`);
});