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

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

import RelayRequest from './RelayRequest';
import RRNLError from './RRNLError';
export class RRNLRequestError extends RRNLError {
  constructor(msg) {
    super(msg);
    this.name = 'RRNLRequestError';
  }
}

/**
 * Formats an error response from GraphQL server request.
 */
export function formatGraphQLErrors(request, errors) {
  const CONTEXT_BEFORE = 20;
  const CONTEXT_LENGTH = 60;
  if (!request.getQueryString) {
    return errors.join('\n');
  }
  let queryLines = [];
  const queryString = request.getQueryString();
  if (queryString) {
    // When using persisted query, queryString is an empty string.
    queryLines = queryString.split('\n');
  }
  return errors.map(({
    locations,
    message
  }, ii) => {
    const prefix = `${ii + 1}. `;
    const indent = ' '.repeat(prefix.length);

    // custom errors thrown in graphql-server may not have locations
    const locationMessage = locations && queryLines.length ? '\n' + locations.map(({
      column,
      line
    }) => {
      const queryLine = queryLines[line - 1];
      const offset = Math.min(column - 1, CONTEXT_BEFORE);
      return [queryLine.substr(column - 1 - offset, CONTEXT_LENGTH), `${' '.repeat(Math.max(offset, 0))}^^^`].map(messageLine => indent + messageLine).join('\n');
    }).join('\n') : '';
    return prefix + message + locationMessage;
  }).join('\n');
}
export function createRequestError(req, res) {
  let errorReason = '';
  if (!res) {
    errorReason = 'Server return empty response.';
  } else if (res.errors) {
    if (req instanceof RelayRequest) {
      errorReason = formatGraphQLErrors(req, res.errors);
    } else {
      errorReason = JSON.stringify(res.errors);
    }
  } else if (!res.json) {
    errorReason = (res.text ? res.text : `Server return empty response with Status Code: ${res.status}.`) + (res ? `\n\n${res.toString()}` : '');
  } else if (!res.data) {
    errorReason = 'Server return empty response.data.\n\n' + res.toString();
  }
  const error = new RRNLRequestError(`Relay request for \`${req.getID()}\` failed by the following reasons:\n\n${errorReason}`);
  error.req = req;
  error.res = res;
  return error;
}