node.js - Efficient way to handle error cases in REST Apis -

i writing rest api in node.js. expect @ max 5 parameters arrive in request. if there unidentified parameters wish send 400 bad request. handling in following way:

server.route({       method: "get",       path  : "/test",       handler : function (request, reply) {            if (request.query.a || request.query.b || request.query.c || request.query.d || request.query.e)           {               // processing           }           else {              reply("no valid parameters").code(400);            }       } }); 

right not handle case if there valid , invalid cases. can solve using more if conditions. wondering if there standard or more efficient method used developers

hapi has built-in validation support. can use joi validate query:

var joi = require('joi');  ...  server.route({     method: 'get',     path: '/test',     config: {         validate: {             query: {                 a: joi.string(),                 b: joi.string(),                 c: joi.string(),                 d: joi.string(),                 e: joi.string()             }         }     },     handler: function (request, reply) {          return reply('ok');     } }); 

if send request /test?g=foo, following response:

{ statuscode: 400,   error: 'bad request',   message: '"g" not allowed',   validation: { source: 'query', keys: [ 'g' ] } }