android - JavaScript Exception Is Lost In Promise Chain -

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i new javascript promises , trying implement them phonegap code on android device. want log exceptions , looks exceptions swallowed somewhere. see sample code below. exception thrown due call non-existent function "thiswillfail" not show anywhere. commented out irrelevant code , added code force addrecord promise called. code checks if record exists and, if not, return addrecord promise error is. not using 3rd party libraries. doing wrong?

edit: if add promise in chain "dosomethingwithrecord", promise called when expectation skip catch.

function testpromiseexceptionhandling() { var record = null; var checkforrecord = function () {     return new promise(function (resolve, reject) {         //getdata(         //    function (data) {         var data = "";         if (data != "") {             //record = new record(data);             record = "existed";             resolve();         }         else return addrecord();         //    },         //    function (err) {         //        reject(new error("an error occurred retrieving data, msg=" + err.message));         //    });     }); }; var addrecord = function () {     return new promise(function (resolve, reject) {         thiswillfail();         //add record         var success = true;         record = "new";         if (success) resolve();         else reject(new error("add record failed"));     }); }; var dosomthingwithrecord = function () {     return new promise(function (resolve, reject) {         alert(record);         resolve();     }); };   try {     checkforrecord()         .then(dosomthingwithrecord())         .catch(function (err) { alert(err.message);})         .then(function () { alert("done"); }); } catch (err) {     alert(err.message); }}

you can't return promise constructor, when do:

else return addrecord();

nothing wait addrecord, instead, want resolve addrecord wait before resolving promise:

else resolve(addrecord());

however, if code can return addrecord() instead of using promise constructor anyway. promise constructor (new promise) useful converting non-promise apis promises , aren't supposed used promisified apis. use thens instead.


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