set getOAuthAccessToken to whatever the strategy uses

Author: bencmbrook

lib/refresh.js

@@ -54,6 +54,10 @@ AuthTokenRefresh.use = function(name, strategy) {
       strategy._refreshURL || strategy._oauth2._accessTokenUrl,
       strategy._oauth2._customHeaders)
   };
+  
+  // Some strategies use overwrite the getOAuthAccessToken function to set headers
+  // https://github.com/fiznool/passport-oauth2-refresh/issues/10
+  AuthTokenRefresh._strategies[name].refreshOAuth2.getOAuthAccessToken = strategy._oauth2.getOAuthAccessToken;
 };
 
 /**