fix: Ensure the warning is non longer option - older gets migrated

[aiAdrian]

No description provided.

[louisgreiner]

I cannot reproduce the bug this should fix. Can you provide such a json?

[aiAdrian]

netzgrafik_rhb.json

or
netzgrafik_bls.json

[louisgreiner]

Thanks for the files, I reproduced the bug.

I'm not a fan of this approve, because it adds a manual migration that adds a lot of noise to the code. I wonder how, in this same file, backwardTravelTime sometimes includes a warning and sometimes not.

I will try to think of an alternative solution. Edit: I couldn't find other solution :s

[emersion]

Can we instead adjust hasXXXWarning() functions to check for null and undefined instead of just for null? e.g.

  hasTravelTimeWarning(): boolean {
    return Boolean(this.travelTime.warning);
  }

[louisgreiner]

The other concern I have is that old files have backwardTravelTime not having the field warning and if we don't migrate the data, importing and exporting such a file will result in a file still not including the warning attributes. Should we do something about it?

[aiAdrian]

The questions is how we ensure that we are downwards compatible.

[louisgreiner]

After some discussion, we could try this: #974 (comment)

[louisgreiner]

@aiAdrian what do you think of this solution (#974 (comment))? It would avoid having a migration method called each time in the constructor