feat: adds support for client generics, improving type safety in comb…

[Enngage]

This PR adds ability to provide generics to client such as:

type CoreContentType = IContentItem<IContentItemElements, 'a', 'b', 'c', 'd', 'e', 'd'>;

type ClientTypes = {
    readonly contentItemType: CoreContentType;
    readonly contentTypeCodenames: 'a' | 'b';
    readonly workflowCodenames: 'a' | 'b';
    readonly worfklowStepCodenames: 'a' | 'b';
    readonly collectionCodenames: 'a' | 'b';
    readonly taxonomyCodenames: 'a' | 'b';
    readonly languageCodenames: 'a' | 'b';
    readonly elementCodenames: 'a' | 'b';
};

const client = new DeliveryClient<ClientTypes>

The idea is that the ClientTypes would be generated by https://github.com/kontent-ai/model-generator-js

[IvanKiral]

I don't see any updates on readme :/ How I as the end user would know how to utilize model generator with this?

[IvanKiral]

I think this class doesn't need to send the whole type of object TClientTypes it just needs need type TClientTypes['contentItemType'].

It would be easier to test this class if you need to pass only the necessary stuff

Check also the other classes for this

[Enngage]

It doesn't, the only reason I passed all types is for consistency and ease of use. Do you think it's worth splitting?

[IvanKiral]

As I understand the point of ease of use, I am not sure about consistency. These generic types are new after all, so they are only consistent with the new code you are writing :).
For me there are two options:

1. Pass only the required type, which is more correct of system modelling. This improves the type dependency coupling.
   • If I wanted to unit test only ElementMapper I would need to define the whole type to the generic. That would be bothering as the class really only needs type of contentItemType. So for me as a tester of ElementMapper would be nice to pass just ElementMapper<TContentItemType>
2. If you just want to pass the object everywhere, I guess there is not as elegant workaround to satisfy both ends (ease of use and creating only part of the object)
   ElementMapper<TClientTypes extends Pick<ClientTypes, 'contentItemType'>>

[IvanKiral]

the same as the comment for element mapper

[Enngage]

That's a fair point, I will have to update the readme, but currently, the model generator does not yet support this. I wanted to finalize this first.

One idea I was toying with is to enforce the generic argument when creating a delivery client. This way developers would have to look at this & either use the default types or generate the models. It would also help with the discoverability of the model generator and therefore improve the developer experience across all projects using it. What do you think @IvanKiral ?