How to tell if rake ts:index failed, programmatically

[Ngan]

Hi, in my build script, I have it running the task: "ts:index".  I'd like build to stop and fail immediately if the "ts:config" or "ts:index" tasks fails.  Is there a way to figure out if either of them did fail, programmatically?

If it helps, I'm running the task by:

Rake::Task["ts:index"].invoke

Thanks!