In your tests insert debugger;
command
exports['Main test'] = function(test){
debugger;
test.expect(1);
test.ok(true, 'Must be ok');
test.done();
};
And start all this
$ node --debug-brk `which nodeunit` test.js
Now in browser press F8, then F10, and you are right on the next line after first debugger;
command in your test.
But I prefer to start everything with node-supervisor, that restart test automatically when test finished or files in project directory changed:
$ npm -g install supervisor node-inspector
$ # console 1
$ # supervisor restarts node-inspector when it quits
$ # ignores file changes
$ supervisor -i . -x node-inspector .
$ # console 2
$ supervisor --debug-brk -- `which nodeunit` test/index.js