Strange behavior when saving arrays with undefined values

[arggh]

If I try to save my Astronomy document with an array like this var a = [undefined, undefined, 'foobar', undefined], only the two last entries will be saved, resulting in ['foobar', undefined].

Reproduction:

https://github.com/arggh/astronomy-array-issue

How it works:

1. Run meteor
2. Observe the type of array we are about to save (displayed on page for convenience)
3. Click the Save -button
4. Observe what actually got saved in the database (displayed on page for convenience)

[lukejagodzinski]

@arggh Yep, indeed there is a bug. Thanks for noticing it. I've already fixed it and I will release a new version that fixes that.

[lukejagodzinski]

Fixed in Astronomy 2.5.0

[arggh]

I confirm the issue is now fixed, thanks! 👍

Btw, is this the "correct" way to define a field, which holds an Array of mixed nulls/undefineds and Strings? (with no validation yet for actually having only nulls/undefineds or Strings obviously)

fields: {
    values: {
      type: Object,
      default: function() {
        return [];
      },
      validators: [
        { type: 'array' }
      ]
    }
  }

[lukejagodzinski]

Actually, there is no official way of doing it but if it works in your example then it's ok. In fact, an array is just an object so it should work properly.

[arggh]

It works, it just looks a bit hacky so I was wondering if I had missed something in the docs.

Maybe it could be a good idea to consider one or many of these solutions:

• Possible to define multiple types for an Array eg. type: [String, null, Boolean]
• Possible to define the specified type as optional, meaning, it can also be null or undefined
• Possible to define Array containing anything: type: []

[lukejagodzinski]

Possible to define multiple types for an Array eg. type: [String, null, Boolean]

It is actually possible using unions

Possible to define the specified type as optional, meaning, it can also be null or undefined

That would be the best solution. It would be similar to what we have in GraphQL. However, it would require entire redesign of the types system in Astronomy.

Possible to define Array containing anything: type: []

That actually might be the easiest one to do. Will think about implementing it.

[jdalrymple]

Possible to define multiple types for an Array eg. type: [String, null, Boolean]

It is actually possible using unions

Possible to define the specified type as optional, meaning, it can also be null or undefined

That would be the best solution. It would be similar to what we have in GraphQL. However, it would require entire redesign of the types system in Astronomy.

Possible to define Array containing anything: type: []

That actually might be the easiest one to do. Will think about implementing it.

Unions dont support null types or optional keys afaik