I’m doing Ruby & Rails development for almost a year now and I’m loving it! I’ve also done 2 commercial projects (their source is in private github repos, I can provide it if needed) and I’m currently looking for a job.
One might need non of those skills at all in a general case; it depends on the job opening, really. That’s how your question was phrased to my knowledge. As to this particular job, I’ve no idea.
Oh, well then you should look into behavior / test driven development and testing (for JS) tools similar to http://pivotal.github.com/jasmine/
Also you must learn CoffeeScript as it comes bundled with Rails (also it is very good ;),
Next you should learn jQuery
With Jasmine + CoffeeScript + jQuery knowledge (and possible another library like Cucumber) you’ll be able to do A LOT, IMO (just because BBD is so powerful).
Oh, well then you should look into behavior / test driven development
and testing (for JS) tools similar to http://pivotal.github.com/jasmine/
Also you must learn CoffeeScript as it comes bundled with Rails (also it
is very good ;), Next you should learn jQuery
JQuery I can agree with.. but expecting a developer to know Coffescript
is laughable (no offense) if you ask me. What is the big deal when it
comes out as normal JS in the end anyways?
Coffeescript only slims it down in some ways and makes it a bit more
rapid for some programmers but others can program normal Javascript just
as fast. I know a Javascript developer who was completely hindered by
Coffeescript.
IMO with all things you should learn the actual language before you
bother with a framework and/or library. That means IMO you should
probably learn how to do your own requests with JS before you use jQuery
to do that request that way you understand how it works can debug a bad
situation, you don't want to be that developer who builds something and
then doesn't know how it works so when it all comes falling down you
have no idea what to do. Or the developer who does something the way
the framework implies and then it turns out you did it all wrong and
people are calling you bad. I know that doesn't always apply but
clients like a developer who actually knows how what they are using works.