assume.wait but immediately calls next on failure

[terinjokes]

This might be better served by a try/catch wrapper, or something like tryit, but wanted to get feedback.

The assume.wait function is supposed to make it much similar to handle async tests. However, it's still a bit annoy to remember to capture errors to be able to pass them to next. For example:

 it('does async things', function (done) {
   next = assume.wait(2, 4, done);

   asynctask(function (err, data) {
     assume(err).is.a('undefined');
     assume(data).equals('testing');

     next();
   });

   asynctaskfail(function (err, data) {
     assume(err).is.a('undefined');
     assume(data).equals('testing');

     next();
   });
 });

If asynctaskfail actually did return an err, one might expect done to be called with the assertion error. Instead nothing happens, and most harnesses will time out after 2 seconds, giving the user the harness's timeout error instead.

To handle this correctly, I must write something similar to the following:

 it('does async things', function (done) {
   next = assume.wait(2, 4, done);

   asynctask(function (err, data) {
     try {
       assume(err).is.a('undefined');
       assume(data).equals('testing');

       next();
     } catch(e) {
       next(e);
     }
   });

   asynctaskfail(function (err, data) {
     try {
       assume(err).is.a('undefined');
       assume(data).equals('testing');

       next();
     } catch(e) {
       next(e);
     }
   });
 });

This isn't much different than the code I had to write before assume.wait, so I'm not sure what benefit it brings to the table in the current iteration.

While reading the documentation and glancing at the example, I expected the assertion functions to immediately call done on error, instead of throwing an exception.