A way to solve the problem of JSON.stringify "serialize cyclic structures" in mocha-phantomjs (https://github.com/metaskills/mocha-phantomjs/issues/104). Required only if you're printing in the console objects with cyclic structures (not very common).

mocha-test-with-modified-stringify.js

describe('functionalityToTest', function() {
        var stringify = JSON.stringify;

        before(function() {
            JSON.stringify = function(obj) {
              var seen = [];

              return stringify(obj, function(key, val) {
                 if (typeof val == "object") {
                      if (seen.indexOf(val) >= 0) { return; }
                      seen.push(val);
                  }
                  return val;
              });
            };
        });

        after(function() {
            JSON.stringify = stringify;
        });

        // tests go here
    });