batchUrl property of URL middleware is not passed req

[chris-verclytte]

Hello,

I wonder why url property is wrapped with req (https://github.com/nodkz/react-relay-network-layer/blob/master/src/middleware/url.js#L26) allowing for data being passed by another middleware through req but batchUrl is not.
My use case is that I am dynamically retrieving the api url with a middleware, and I would like both url and batchUrl to use the api url from req.

[nodkz]

urlMiddleware determines which type of query single or batched via req.relayReqType === 'batch-query' and passes to next middleware just url for fetching (supposing that all other middlewares do not care about url).

So if you want to create more complex logic, do not use urlMiddleware and write your own inline middleware (find example with next => req => {...} in readme.md).

[chris-verclytte]

I agree with that but I am not sure we are talkin gabout the same thing.
I see this example in the documentation:

urlMiddleware({
    url: (req) => '/graphql',
  }),

and thus would expect this code to work:

urlMiddleware({
    url: (req) => req.someProperty + '/graphql',
    batchUrl: (req) => req.someProperty + '/graphql/batch',
  }),

but it seems that batchUrl does not accept a function.

[nodkz]

export default function urlMiddleware(opts = {}) {
  const urlOrThunk = opts.url || '/graphql';
  const batchUrlOrThunk = opts.batchUrl || '/graphql/batch';
  const fetchOpts = opts.opts;

  return next => req => {
    if (fetchOpts) {
      const { headers, ...otherOpts } = fetchOpts;
      Object.assign(req, otherOpts);
      if (headers) {
        Object.assign(req.headers, headers);
      }
    }

    let url;
    if (req.relayReqType === 'batch-query') {
      url = batchUrlOrThunk;
    } else {
      url = urlOrThunk;
    }

    req.url = isFunction(url) ? url(req) : url;

    return next(req);
  };
}

See carefully that url variable assigned to batchUrlOrThunk (opts.batchUrl) or urlOrThunk (opts.url) according to req.relayReqType value. And after that checking is url function or not.

So it should work as you expected.

[chris-verclytte]

Ok got it, my error should came from another part then. I am closing this now as the behavior is the one expected.