Javascript is a very strange and often misunderstood language. One of the byproducts of the many different implementations are the many undocumented features. Among these is the very convenient, especially for fixture data, multi-line string. Here’s how you do it:

  var s= "\
          some text \
          some more lines\
          want line breaks? \n\
          javascript is cool\
  ";

Basically the last character of every line must be a \.