While RegExp would be awesome unfortunately there is no way to serialize a Regexp to JSON. YOu can still create your own execute_script and pass it the string that has a regexp.

Well sure there is, if we wanted to support this:

{some-defined-uuid: string-that-compiles-as-regexp}

(I don't have an opinion on whether this should be supported, but it is certainly *possible* to do so).

Right, this is the sort of thing I have in my client code to work around this. Makes for some ugliness and repetition in the client code... like so:

      // test/driver side
      if (Object.prototype.toString.call(mockDef.url) == '[object RegExp]') {
        // Serialize RegExp with special prefix flag
        mockDef.url = REGEXFLAG + mockDef.url.source;
      }
/*/*/*/*/
      // browser side
      if (mockDef.url.indexOf(REGEXFLAG) === 0) {
        // Marshal RegExp from special string
        mockDef.url  = new RegExp(mockDef.url.substr(3));
      }

Ugly, and of course the REGEXFLAG constant needs to be defined on both sides as well.