text: 'use strict';
  
  var utils = require('./../utils');
  var transformData = require('./transformData');
  var isCancel = require('../cancel/isCancel');
  var defaults = require('../defaults');
  var CanceledError = require('../cancel/CanceledError');
  
  /**
   * Throws a `CanceledError` if cancellation has been requested.
   */
  function throwIfCancellationRequested(config) {
    if (config.cancelToken) {
      config.cancelToken.throwIfRequested();
    }
  
    if (config.signal && config.signal.aborted) {
      throw new CanceledError();
    }
  }
  
  /**
   * Dispatch a request to the server using the configured adapter.
   *
   * @param {object} config The config that is to be used for the request
   * @returns {Promise} The Promise to be fulfilled
   */
  module.exports = function dispatchRequest(config) {
    throwIfCancellationRequested(config);
  
    // Ensure headers exist
    config.headers = config.headers || {};
    
    // validate header is an object
    if (typeof config.headers !== 'object' && config.headers !== undefined) {
      throw new Error('Headers must be an object, currently set to: ' + config.headers);
    }
    
    // Transform request data
    config.data = transformData.call(
      config,
      config.data,
      config.headers,
      config.transformRequest
    );
  
    // Flatten headers
    config.headers = utils.merge(
      config.headers.common || {},
      config.headers[config.method] || {},
      config.headers
    );
  
    utils.forEach(
      ['delete', 'get', 'head', 'post', 'put', 'patch', 'common'],
      function cleanHeaderConfig(method) {
        delete config.headers[method];
      }
    );
  
    var adapter = config.adapter || defaults.adapter;
  
    return adapter(config).then(function onAdapterResolution(response) {
      throwIfCancellationRequested(config);
  
      // Transform response data
      response.data = transformData.call(
        config,
        response.data,
        response.headers,
        config.transformResponse
      );
  
      return response;
    }, function onAdapterRejection(reason) {
      if (!isCancel(reason)) {
        throwIfCancellationRequested(config);
  
        // Transform response data
        if (reason && reason.response) {
          reason.response.data = transformData.call(
            config,
            reason.response.data,
            reason.response.headers,
            config.transformResponse
          );
        }
      }
  
      return Promise.reject(reason);
    });
  };
  