Do we still need to define the type explicitly when it's nullable

[micalevisk]

Using v8.7.6

If I recall correctly, in the past we'd have to use @AutoMap(() => Type) if the type of some property has an union with null. But now if we use nullSubstitution it doesn't maps null anymore and I believe this is a bug -- actually, looks like the nullSubstitution is lost when we use extend

But my question is: do we still need to explicitly type destination's type if it has an union with null? I didn't find any mention to that in the docs

See demo code

import { createMap, createMapper, extend, nullSubstitution, forMember } from '@automapper/core';
import { classes, AutoMap } from '@automapper/classes';

const mapper = createMapper({
  strategyInitializer: classes(),
});

class S {
  @AutoMap(() => String) // Doesn't work
  // @AutoMap() // Does works
  foo: string | null
}

class D {
  @AutoMap()
  foo?: string
}

class D2 extends D {}

createMap(mapper,
  S, D,
  forMember(
    d => d.foo,
    nullSubstitution(undefined),
  )
)
createMap(mapper,
  S, D2,
  extend(S, D)
)


const s = new S()
s.foo = null

console.log(
  mapper.map(s, S, D) ,
  mapper.map(s, S, D2) ,
)
/*
D { foo: undefined }
D2 { foo: null }
*/

[micalevisk]

ping @nartc 😢

[nartc]

Sorry for the delay, I'm currently on vacation (have been on vacation for 2 months) and will be back in about 3 weeks.

[nartc]

Hi @micalevisk, it was a bug with extend(). I kept the old behavior (you still need to explicitly set a type for Null union). Check out the latest version