When using sails-disk any attribute with `unique:true` must also have `required:true`

Sails version: 1.1.0
Node version: 8.14.0
NPM version: 6.4.1
DB adapter name: sails-disk
DB adapter version: N/A
Operating system: Windows 10

I have one-to-one relationship. A task must have a message. Even though I set required to true in the Task.message relationship, I keep getting error "In attribute message of model task: When using sails-disk, any attribute with unique: true must also have required: true". My code:

/api/models/Task.js

message: {
      model: 'message',
      required: true,
      unique: true
},

/api/models/Message.js

task: {
      collection: 'task',
      via: 'message'
},

When using sails-disk any attribute with unique:true must also have required:true.

I asked on gitter and they said:

Did you try with a real database? May be there is a bug in sails-disk and throwing a wrong message. May be sails-disk adapter is looking at the relationship as 1-to-m. I suggest execute your code with a real database and then post your findings

I tried with sails-mysql and no issue. I reported this in gitter to see if they could help more, they said not to use sails-disk.

I think this is a bug, and I don't want to just ignore it if I found it. So reporting it here.

Gitter comments:

sails-disk is very simple implementation based on json file. It is not a DBMS so do not expect much from it. It is made available for quick prototyping. Do not use

It would be nice if we could fix sails-disk so it didn't get a bad rep like this. They tell me simply to not use it.

Reproduce the relationship setup from /api/models/Task.js and /api/models/Message.js using sails-disk, then compare the result with sails-mysql. Start by tracing how sails-disk interprets the required, unique, model, and collection attributes. Done means the valid one-to-one relationship no longer produces the misleading validation error under sails-disk.