How to create Metadata with union type?

[SymphonyNineth]

I'm using automapper with Pojo strategy. I have to define metadata for it, but "postalCode" field have a union type.

    PojosMetadataMap.create<FrontendData>("FrontendData", {
       address: String,
       postalCode: null | number,
       latitude: Number,
       longitude: Number,
    });

Unfortunately the syntax null postalCode: null | number does not work. I have looking in documentation but there was nothing about using union types with this strategy - https://automapperts.netlify.app/docs/strategies/pojos/. Is there a way to do that?

[nartc]

As of the moment, there's no union support for metadata. number | null is still Number in this case. If the source postalCode is null then it will be mapped to null, if the source postalCode is undefined then it will be mapped to undefined. You can use undefinedSubstitution(null) to convert it to null if the source is undefined

[SymphonyNineth]

Hi. Thank you for your time.
So i can just specify type number in metadata, even if in the interface the type is null | number and it will work.
And can i specify undefinedSubstitution for every field?

[nartc]

There's no global member map configuration :( afterMap() can be used to say like: after I map, I want to turn all undefined to null by a simple loop

[SymphonyNineth]

That will work thank you very much.
And one last question - When some field is present in destination object and absent in source object i get an error. Can i tell it to just ignore the fields that are absent in source?

[SymphonyNineth]

And actually last question - What can this error mean Mapping is not found for Symbol(Label) and function String() { [native code] } ??
Sorry if I'm taking too much of your time.