Where do you plan to use distance and CO2 emissions?

I'm not sure that putting them into a Task entity is a good idea. It seems to me that distanceFromPrevious, at least, belongs more to a TaskCollectionItem, as it depends on the position of a Task in a list and should be managed together.

I was wondering about that as well.

At the time I put it on Task directly, as we are for real interested only on the last value: a task may be assigned several days in a row, but actually only the last assignment if several make sense (when we accomplish the task for real). so in reality there is only one value we are interested into.

(also coopcycle/coopcycle#166 )

we are for real interested only on the last value

Then it seems a waste of time to recalculate all these values all the time. Maybe subscribe to a task:done event and calculate them only then? (I'd also rename the fields in that case to something in the past like traveled_distance, co2_consumed)

actually I put it there because we already call the geocoder at this point, so we have the distance data without an extra call.
however this is true that we update all these tasks objects so it might result in more SQL calls than before. but i am not sure about that, I can check.
maybe it makes more sense architecture-wise to move the logic to task:done handler, you ll prefer that?

Yes, I think it’s better if they are set after task:done event, makes the logic behind these fields a bit more clear