ReferenceMany: insert an empty array

[ajax13]

Related to #1195

[malarzm]

@ajax13 thanks for the PR! We require though that each change has a corresponding test so there will be no regressions in the future. Also I'm afraid that simply putting empty arrays after years of not doing anything will be a BC break for people looking for not existing field through query builder... thoughts on this @alcaeus @jmikola?

[jmikola]

Also I'm afraid that simply putting empty arrays after years of not doing anything will be a BC break for people looking for not existing field through query builder...

I think a BC-friendly approach would be having an option on the EmbedMany or ReferenceMany option that allows an empty array to be created if the collection is empty (instead of leaving the field omitted).

If I had to guess, the current behavior of omitting empty collections is related to @Field and nullable (by default, fields with null values are unset in the document).

Otherwise, this seems like something you might simply change in 2.0 and document in the release notes.

[alcaeus]

I think a BC-friendly approach would be having an option on the EmbedMany or ReferenceMany option that allows an empty array to be created if the collection is empty

I agree on this and I also agree on using nullable, with the only difference that we wouldn't store null but rather [] (or {} if using set or atomicSet strategies).

[malarzm]

Putting into 2.0 bucket

[spiider8]

Hi, will be this funkcionality merged sometime pls?

[malarzm]

We can't merge the PR as-is, it requires more work. Somebody interested needs to pick it up

[khaperets]

Hi, will be this funkcionality merged sometime pls?

I hope someone fixes it

[malarzm]

Superseded by #2547