instrumenting does not log strings

[Adam Peller]

dijit/Tree _setPathsAttr does stuff like

				def.reject("Could not expand path at " + nextPath);

passing a string to reject. instrumenting.js only seems to know how to log error objects, looking for error.stack. If passed just a string, an empty console.error is issued. Is this a proper use of the Deferred API? If so, perhaps this is a Deferred issue and instrumenting.js should handle strings?

[Mark Wubben]

It could certainly cast the error object to a string. This is what I tend to do normally:

console.error(error && error.stack || error);

Because instrumenting also tries to log a stack trace we can't quite do that, so I'll just cast it to a string.

Generally though I think promises should only be rejected with non-error values if the rejection is used as a way to short-circuit a part of the promise chain. You could throw a result object so 5 other normal callbacks don't get called. In this particular case we're dealing with an actual error, so it should be an error instance not a string.

[bill]

OK, I'll fix, thanks for catching the problem.

[bill]

In [29086]:

reject() should be called with an Error, not a String, fixes #15579 !strict

[Mark Wubben]

In [29170]:

Log original error, as well as any stack trace

Refs #14615, #15579 !strict