Tweaks to error reporting in Tracker.

[Slava]

• Allow passing an onError callback to Tracker.autorun.
• Workaround the issue described in exceptions logged by Meteor code (not uncaught exceptions) don't use source maps for stack trace #3655 by logging parts of error message
  separately.

Attempts to fix #3655

[stubailo]

The onError callback doesn't actually help fix #3822, does it? Or would it help because you can throw the error yourself?

[Slava]

The logging part does help. onError extends the API to make it more flexible and up to the user to handle errors. (errors printed to console are not easy to handle fwiw).

It just occurred to me, this change might "break" some tests as the code doesn't use Meteor._debug anymore.

[glasser]

Since most users of Tracker.autorun (a very user-visible API) won't use this optional feature, it should probably be a named option?

[Slava]

Will do!

[stubailo]

@Slava ping!

[Slava]

@stubailo @glasser updated the PR. Added a test and made sure that the Meteor._supress_log is handled correctly (since now we print more than one line).

[Slava]

ping :)

[stubailo]

LGTM

[Slava]

Yay, merged to release 1.1 branch

(cc @philcockfield)

[hharnisc]

👍