Add way to override default fields

Author: pcofilada

README.md

@@ -48,7 +48,8 @@ Providers Setup
 {
   appId: '1234567890',
   callback: 'fb1234567890://authorize',
-  scope: 'user_friends' // you can add some additional scope here
+  scope: 'user_friends', // you can override the default scope here
+  fields: ['email', 'first_name', 'last_name'], // you can override the default fields here
 }
 ```
 - Add the deep link scheme for the callback (Your Bundle ID, eg `fb1234567890`) to your `AndroidManifest.xml` eg https://github.com/adamjmcgrath/ReactNativeSimpleAuthExample/blob/master/android/app/src/main/AndroidManifest.xml#L28-L33

lib/fixtures/facebook.js

@@ -11,8 +11,8 @@ const DANCE_CALLBACK = `fb0123456789://authorize#
 `.replace(/\s+/g, '');
 
 const USER_INFO_URL = `https://graph.facebook.com/v2.8/me?
-  fields=id,name,first_name,last_name,verified,email,location,link,
-  gender,cover,picture,friends,website&access_token=ACCESSTOKEN123
+  &access_token=ACCESSTOKEN123
+  &fields=id,name,first_name,last_name,verified,email,location,link
 `.replace(/\s+/g, '');
 
 const USER_INFO_RESPONSE = {

lib/providers/facebook.js

@@ -7,6 +7,7 @@ import {
   pipeP,
   replace,
   set,
+  merge,
 } from 'ramda';
 import {
   authorizationUrl,
@@ -15,21 +16,39 @@ import { fromQueryString } from '../utils/uri';
 
 const SCOPE = 'email public_profile';
 const AUTH = 'https://www.facebook.com/dialog/oauth';
-const ME = 'https://graph.facebook.com/v2.8/me?fields=' +
-  'id,name,first_name,last_name,verified,email,location,link,' +
-  'gender,cover,picture,friends,website';
+const ME = 'https://graph.facebook.com/v2.8/me?';
+const FIELDS = [
+  'id',
+  'name',
+  'first_name',
+  'last_name',
+  'verified',
+  'email',
+  'location',
+  'link',
+];
 
 export const authorize = (
   { dance, request },
-  { appId, callback, scope = SCOPE },
+  { appId, callback, scope = SCOPE, fields = FIELDS },
 ) => pipeP(
   dance,
   replace('#', '?'),
   fromQueryString,
+  set(lensProp('credentials'), __, {}),
+  merge({ fields }),
 )(authorizationUrl(AUTH, appId, callback, scope));
 
-export const identify = curry((request, credentials) => pipeP(
-  partial(request, [`${ME}&access_token=${credentials.access_token}`, {}]),
+export const identify = curry((request, { credentials, fields }) => pipeP(
+  partial(
+    request,
+    [
+      `${ME}` +
+      `&access_token=${credentials.access_token}` +
+      `&fields=${fields.join(',')}`,
+      {},
+    ],
+  ),
   invoker(0, 'json'),
   set(lensProp('user'), __, {}),
   set(lensProp('credentials'), credentials),