ReSharper 6.1 comes with support for Unit Testing Javascript code using QUnit. Only thing I wonder about how to best set up my test environment. Right now I have all my JS files in \Scripts and the according filename-test.js in \Scripts\tests. Does it also work to put the test files in a dedicated test project?
Also I'm not sure where to put my html snippets. For me it looks like ReSharper does not support additional html files but creating the html using jQuery is a pain in the ass.
In this post you can see an example of how to set up ReSharper with QUnit http://blogs.jetbrains.com/dotnet/2011/03/resharper-6-introduces-support-for-javascript-unit-testing/
You can use reference paths to organize your code a little but different project AFAIK is not available.