example.ts

  describe("Event save", () => {
    it("Should be able to retrieve an event from the database, mutate the data, and save it", (done) => {
      return eventRepo.findOneById('54c305fd1431209617db8221').then((eventO: m.Option<domain.Event>) => {
        var event = eventO.get();
        event.hash = 'foobar';
        return eventRepo.save(event).then((savedEvent) => {
          return eventRepo.findOneById('54c305fd1431209617db8221').then((updatedEvent) => {
            updatedEvent.isDefined.should.be.true
            updatedEvent.foreach((ev) => ev.should.eql(event))
          });
        });
      })
      .done(done)
    });
  });

revised with match.ts

  describe("Event save", () => {
    it("Should be able to retrieve an event from the database, mutate the data, and save it", (done) => {
      return eventRepo.findOneById('54c305fd1431209617db8221').then((eventO: m.Option<domain.Event>) => {
        eventO.match({
          Some: (event) => {
            event.hash = 'foobar';
            eventRepo.save(event).then(() => {
              return eventRepo.findOneById('54c305fd1431209617db8221').then((updatedEventO) => {
                updatedEventO.match({
                  Some: (ev) => ev.should.eql(event)),
                  None: () => // what do
                })
              });
            });        
          },
          None: () => // what to do here?
        })
      })
      .done(done)
    });
  });