react-relay-network-modern/es/RelayNetworkLayer.js

Network Layer for React Relay and Express (Batch Queries, AuthToken, Logging, Retry)

import { Network } from 'relay-runtime';
import RelayRequest from './RelayRequest';
import fetchWithMiddleware from './fetchWithMiddleware';
export default class RelayNetworkLayer {
  constructor(middlewares, opts) {
    this._middlewares = [];
    this._rawMiddlewares = [];
    this._middlewaresSync = [];
    this.noThrow = false;
    const mws = Array.isArray(middlewares) ? middlewares : [middlewares];
    mws.forEach(mw => {
      if (mw) {
        if (mw.execute) {
          this._middlewaresSync.push(mw.execute);
        } else if (mw.isRawMiddleware) {
          this._rawMiddlewares.push(mw);
        } else {
          this._middlewares.push(mw);
        }
      }
    });
    if (opts) {
      this.subscribeFn = opts.subscribeFn;
      this.noThrow = opts.noThrow === true;

      // TODO deprecate
      if (opts.beforeFetch) {
        this._middlewaresSync.push(opts.beforeFetch);
      }
    }
    this.fetchFn = (operation, variables, cacheConfig, uploadables) => {
      for (let i = 0; i < this._middlewaresSync.length; i++) {
        const res = this._middlewaresSync[i](operation, variables, cacheConfig, uploadables);
        if (res) return res;
      }
      return {
        subscribe: sink => {
          const req = new RelayRequest(operation, variables, cacheConfig, uploadables);
          const res = fetchWithMiddleware(req, this._middlewares, this._rawMiddlewares, this.noThrow);
          res.then(value => {
            sink.next(value);
            sink.complete();
          }, error => {
            if (error && error.name && error.name === 'AbortError') {
              sink.complete();
            } else sink.error(error);
          })
          // avoid unhandled promise rejection error
          .catch(() => {});
          return () => {
            req.cancel();
          };
        }
      };
    };
    const network = Network.create(this.fetchFn, this.subscribeFn);
    this.execute = network.execute;
    this.executeWithEvents = network.executeWithEvents;
  }
}