Handle spread of non-object

[AlbertLucianto]

In proposal-object-rest-spread, it is stated that:

3. If source is undefined or null, let keys be a new empty List.

Practically, you can try on Chrome console to see the output of non-object spread. As an example:

Currently, if you do this (spreading non object), typescript will raise

Spread types may only be created from object types.ts(2698)

But actually it's allowed and here's an issue related to this.

[felixputera]

If I'm understanding correctly, you're expecting this transform to allow spreading non-object as per the ES proposal.

I'd say that this is not the objective of this transform (and sorry for choosing a ambiguous name), which is to re-write spreaded objects as property assignments. I had updated the README (https://github.com./felixputera/ts-transform-object-spread#motivation) with more details so I hope that it clarifies my intention!

Thanks for opening an issue anyway!