Why does my Promise fall with error?

Asked Mar 28 '16 at 14:38

Active Mar 28 '16 at 14:47

Viewed 33 times

I'm testing how ES6 promises handle errors. I think that Promises never throw errors, but instead they rejects with proper errors.

I can not understand why this promise

var request = require("request"); // popular npm library
new Promise((resolve) => {
  request("http://ya.ru", (err, res, body) => {
    sdcsdcsdc.sdcsdcsdc.sdcsdcsdc.sdcsdcsdc
  });
})

falls with error (and breaks my script):

Promise { <pending> }
ReferenceError: sdcsdcsdc is not defined
    at Request._callback (repl:1:74)
    ...

, but this one

new Promise((resolve) => { sdcsdcsdc.sdcsdcsdc.sdcsdcsdc.sdcsdcsdc })

happily rejects without breaking my script:

Promise { <rejected> [ReferenceError: sdcsdcsdc is not defined] }

edited Mar 28 '16 at 14:47

asked Mar 28 '16 at 14:38

Aleksei Chernenkov

Please fix the syntax errors in your scripts before asking why they fail. – Tomalak Mar 28 '16 at 14:41
1

There is no "syntax errors". I used "undefined" vars to test how it will work. And it works differently for this two promises – Aleksei Chernenkov Mar 28 '16 at 14:43
Then you should explain that circumstance in an introductory paragraph. Too many people post botched code. – Tomalak Mar 28 '16 at 14:44
Also, you should include the `request()` function definition. – Tomalak Mar 28 '16 at 14:46
Thanks. Added more details – Aleksei Chernenkov Mar 28 '16 at 14:49
1

In short: `request(…, (…)=>{…})` is not a promise callback. See that duplicate for details. – Bergi Mar 28 '16 at 14:53

Why does my Promise fall with error?

0 Answers0