gistfile1.txt

var ipp = require("ipp");
sinon.stub(ipp, "Printer");
var stub_printer = sinon.createStubInstance(ipp.Printer);
ipp.Printer.returns(stub_printer);

// tests
var p = new Printer(device, cpus_name, base_name, ipp_uri);
expect(ipp.Printer).to.have.been.calledWith(ipp_uri + "/printer" + cups_name);
expect(p.ipp_printer).to.equals(stub_printer);
var testing_error = new Error("just testing");

stub_printer.execute.yields(testing_error);

p.setup(function (err) {
    expect.stub_printer.execute.to.have.been.calledOnce;
    expect(err).to.exist.and.to.eql(testing_error);
});

pas oublier de ipp.Printer.restore() et re-stub entre chaque test