node.js - Blubird never hits the .catch statement -

i using node.js, bluebird , redis. given:

redisclient.hmsetasync([key, 'sn', sn, 'make', make])     .then(redisclient.setasync(key + ":radio", radioarray))     .then(tmatic.send(res, 200))     .catch(function (e) {         console.log("error reading file", e);         tmatic.send(res, 500);     }); 

when "radioarray" empty, redis throws exception:

unhandled rejection error: err wrong number of arguments command 

this code sends 200 response back. whey doesn't hit .catch() method , throw 500?

answer! after hacking half hour, came this. macareno.marco!

redisclient.hmsetasync([key, 'sn', sn, 'make', make])         .then(function saveradios() {             if (radioarray.length) {                 console.log("radio");                 return redisclient.setasync(key + ":radio", radioarray)             }         })         .then(function () {             tmatic.send(res, 200);         })         .catch(function (e) {             console.log("error:", e);             tmatic.fail(e, res);         }); 

when using line:
.then(tmatic.send(res, 200))
parameter being evaluated, , waiting function returned bluebird may call it. should use function instead, so:

.then(function(res) {     tmatic.send(res, 200); }