I spent all afternoon chasing this bug down. In the end, I learned that the same line of JavaScript code when run in NetSuite’s debugger acts differently than when run in a RESTlet. How can that be?

First, let’s cover some of the really quirky stuff regarding arrays. All my testing was done in SuiteScript 2.0 under NetSuite version 2020.1. I tested in debugger and in a RESTlet I was working on. At issue: Array methods.

[‘123′,’456′,’789’].find(‘456’) will not run in either debugger or a RESTlet. It throws an error when executing the statement.

[‘123′,’456′,’789’].findIndex(‘456’) same!

[‘123′,’456′,’789’].filter(‘456’) to my amazement, actually works and produces consistent results when run client-side, or server-side in debugger or a RESTlet. Awesome!

Here is where it gets annoyingly confusing.

[‘123′,’456′,’789’].indexOf(‘456’) does not throw an error when executing this statement in either scenario. It runs in both debugger and in a RESTlet. However, in debugger it produces a result of 1 and in a RESTlet (also running SuiteScript 2.0) it produces a result of -1.

BEWARE JAVASCRIPT DEVELOPERS. DON’T LET THIS TAKE A BITE OUT OF YOUR BACKSIDE LIKE IT DID MINE!

Oh… One more thing. Since .filter() works, feel free to give this a try. It’s not as efficient as either .findIndex() or .indexOf(), but in my preliminary testing, it works.