Improve {{#each}} errors logging

[MattiSG]

_1 Upvote_ If I pass a currently non-iterable variable to a Spacebars {{#each}}, I get the following exception:

Exception from Tracker recompute function: {{#each}} currently only accepts arrays, cursors or falsey values.
[very long stack trace]

However, I have no hint as to which iterator failed. Even on a medium-sized app, it is extremely time-consuming to narrow down on the responsible template.

I expect the runtime to tell me the name of the template, and the line and column number of the failing iterator.

[MattiSG]

Update: I don't get an actual exception; the console logs that an exception happened, but it is a message relayed by debug.js rather than an error.

This doesn't change the need.

[avital]

Yes, you're right -- at the moment, it's very hard to figure out which line in your .html file triggers this error. It might be tricky to get this right so I don't see us resolving this very soon, but I'll leave this issue open so that we can track how frequently people hit it.

[mixflame]

I'm hitting this issue. It happened randomly. I have tried returning false in all of my helpers.

[mixflame]

Got around it, but not sure how. This is a hard one to debug. Just saying.

[art3i]

just happened now; got this same issue.

[vladholubiev]

+1 faced this right now

[webdevbrian]

Getting this currently as well.

[hwillson]

I've migrated this over to meteor/blaze#184 and added a repro. Closing here - thanks!