Immediate exit without warning if a path doesn't exist

[zakdances]

If have watch (v.0.5.1) configured like this

watch:
  sass:
    files: ['fakeDir/*.scss']
    tasks: ['sass:dev']
    options:
      nospawn: false
      livereload: false

And I try grunt watch, the terminal prints out

MyProject zak$ grunt watch
Running "watch:sass" (watch) task
Waiting...MyProject zak$

Why doesn't watch print a message like

"ERROR: 'fakeDir/' doesn't exist. Exiting..."

?

[shama]

If you enabled the option nonull: true it should give you a warning about non-existent files. Although I think it would be a good idea to print a warning if no files are being watched at the time.

[courajs]

👍
I spent 20 mins trying to figure out why it was exiting immediately (I forgot a leading slash)
The nonull option is also not documented anywhere...
Would you accept a PR to fix this?

[shama]

@FellowMD nonull is common to all grunt plugins, see http://gruntjs.com/configuring-tasks#files

[courajs]

Ah that link is helpful -- I'm a bit new to grunt.
Still, I had no idea why it was exiting. This might be solved with an entry in the FAQ "Why does my watch task exit immediately?", or with a message when no targets have any files/directories to watch.
I don't think it's clear or obvious that a watch task without a target would exit, instead of just doing nothing forever, or perhaps running when that file is created.

[shama]

I think we should have it print a message if the watch doesn't match any files. Also keep the process alive as it could be waiting for new files to be added.