how to setup dependent properties?

[hexsprite]

not sure if there's a way to do this or not, looking at the code so far I think not...

but I want to be able to say something like:

Factory.define('event', Actions, {
    end () {
      if (!this.start || !this.duration) {
        throw new Error('must provide start and duration if end not specified')
      }
      return new Date(+this.start + this.duration)
    },
})

That would allow me to optionally provide start and duration. I notice that this object contains the statically defined properties, but not what the user provides as arguments to Factory.create

Any tips on how to implement that?

[dburles]

Hey @hexsprite just wondering what's your specific use case?

You should define your factories as being correct to begin with, i.e with all arguments required to build a valid document already present.

If you need to test with different start and duration values, I would either define a single event factory that generates random values or multiple factories with static dates. In the case of testing I would actually recommend being careful with random values since it can also randomly break tests.

[hexsprite]

I would like to be able to provide a start and duration and if the end is not actually provided I want it to be calculated from those provided parameters. This would be a welcome shorthand for my tests as it means I don't have to do tedious calculations to present a correct end parameter....

[hexsprite]

current:

    Factory.create('action', {
      userId,
      intendedDay,
      start: new Date('1977-03-21T23:30:00.000Z'),
      end: new Date('1977-03-22T00:30:00.000Z'),
      duration: 1 * HOURS,
      order: 1
    })

desired:

    Factory.create('action', {
      userId,
      intendedDay,
      start: new Date('1977-03-21T23:30:00.000Z'),
      duration: 1 * HOURS,
      order: 1
    })

[dburles]

In your app does end live in the database or is it computed say through a collection-helper?

[hexsprite]

needs to be in the DB

[hexsprite]

though that is a good point since one of them should be computed ;) Not ready to make that sort of change in the app yet though

[dburles]

It definitely shouldn't be the role of the factory to calculate the end field. You know what I mean? I assume you must have the same code elsewhere in the app like in an insert method?

A pattern I've done in the past is run the generated factory document through a prepare function (just as the method does with that same function during an insert)

[dburles]

In fact I have a fork of the package that allows you to provide this very function as part of the factory definition ;)