Polka: Sub-app not working when mounted on "/"

[waspeer]

I was trying to mount a sub-app on the root ("/") but it was throwing an error:

/node_modules/polka/index.js:95
        let loop = _ => res.finished || (i < len) && arr[i++](req, res, next);
                                                             ^

TypeError: arr[(i++)] is not a function

I tracked the error back to the .use() function of polka:

use(base, ...fns) {
        if (typeof base === 'function') {
            this.wares = this.wares.concat(base, fns);
                  // SUB-APP IS NOT HANDLED WELL BECAUSE OF THIS CONDITIONAL:
        } else if (base === '/') { 
            this.wares = this.wares.concat(fns);
        } else {
            base = lead(base);
            fns.forEach(fn => {
                if (fn instanceof Polka) {
                    this.apps[base] = fn;
                } else { ... etc ....

I have been trying to find a temporary fix without succes. Or is there another way to go about this?

[lukeed]

Hey, sorry for the delay – on vacation right now 🏖

Mounting via .use('/', ...) is identical to .use(...). That's the same in Express too.

This error, while not a super helpful message on its own, usually means that there's a problem with one of the functions you're trying to assign. Perhaps it's not a function at all.

Can you post a snippet containing the use() block and the functions you're trying to add? Or a reproduction repo would be good too.

Thanks

[waspeer]

Thanks for your reply! Funnily enough I’m leaving on vacation too right now, but I’ll send you some code as soon as I’m back next week.

--
Wannes Salomé

Op 28 augustus 2019 om 21:26:58, Luke Edwards ([email protected](mailto:[email protected])) schreef:

Hey, sorry for the delay – on vacation right now 🏖

Mounting via .use('/', ...) is identical to .use(...). That's the same in Express too.

This error, while not a super helpful message on its own, usually means that there's a problem with one of the functions you're trying to assign. Perhaps it's not a function at all.

Can you post a snippet containing the use() block and the functions you're trying to add? Or a reproduction repo would be good too.

Thanks

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[lukeed]

Haha everyone is gearing up for the end-of-year sprint. Enjoy!

[lukeed]

Just checking in on this – still an issue?

[waspeer]

Hi!
Sorry for being slow. I just ran another test and this still seems to be an issue. This is the code I tested it with:

// INDEX.JS
const polka = require("polka");

const { PORT = 3000 } = process.env;

polka()
  .use(require("./sub"))
  .listen(PORT, err => {
    console.log("Listening!");
  });

// SUB.JS
const polka = require("polka");

module.exports = polka()
  .get("/", (req, res) => {
    res.end("r00t");
  })
  .get("/:name", (req, res) => {
    res.end(`Hello there ${req.params.name}!`);
  });

This time the error is a little different:

/node_modules/polka/index.js:7
    return x.charCodeAt(0) === 47 ? x : ('/' + x);
             ^

TypeError: x.charCodeAt is not a function

The error dissappears when change .use(require("./sub")) to something like .use("sub", require("./sub")).

Hope this helps!

[matthewrobb]

I, too, am having this same problem exactly.

[lukeed]

This is fixed in next and I'm not sure if it's worth backporting at this point.

As mentioned, the easy workaround is to use('/', ...) instead, which achieves exactly the same intended result.

[waspeer]

Hi!

For me using use('/', ...) also throws an error. The error I mentioned when I opened the issue. But to elaborate.

// INDEX.JS
const polka = require("polka");

const { PORT = 3000 } = process.env;

polka()
  .use("/", require("./sub"))
  .listen(PORT, err => {
    console.log("Listening!");
  });

// SUB.JS
const polka = require("polka");

module.exports = polka()
  .get("/", (req, res) => {
    res.end("r00t");
  })
  .get("/:name", (req, res) => {
    res.end(`Hello there ${req.params.name}!`);
  });

This will start running and log Listening!, but when I try to visit localhost:3000 I get the following error:

    let loop = _ => res.finished || (i < len) && arr[i++](req, res, next);
                                                             ^

TypeError: arr[(i++)] is not a function

This is the error I mentioned when I opened the issue.

[RomiC]

Faced with the same issue. A small snippet below:

const polka = require('polka');

polka()
  .use('/', polka().use('/', (req, res) => res.end('sub-app response')))
  .listen(3000);

[lukeed]

Hey guys, sorry for the delay.

I took a look at this a few times & have come to the conclusion that it's not worth fixing on the current stable branch. In order to fix it _correctly_, it requires breaking changes that are already part of the 1.0 work (@next).

I will add complete testing for this (it's not fully implemented, yet) and update this issue once a new release has gone out.

Thanks for you patience :)

[lukeed]

Available with [email protected] via npm install polka@next 👍