Extending data providers in react-admin v3 with typescript

[g3n35i5]

I'm not sure if this is a bug or a wrong implementation on my part. I have already described the problem in detail on stackoverflow.
For this reason I will give only a shortened description here.

What you were expecting:
I want to extend the simple rest provider with my own update method.

What happened instead:
I get the following error:
Property 'update' does not exist on type '(apiUrl: any, httpClient?: ((url: any, options?: Options | undefined) => Promise<{ status: number; headers: Headers; body: string; json: any; }>) | undefined) => DataProvider'. TS2339

Steps to reproduce:
I followed the steps as explained in the documentation

Environment

• React-admin version: 3.1.2
• React version: 16.12.0
• Browser: Chromium
• Stack trace (in case of a JS error):

Property 'update' does not exist on type '(apiUrl: any, httpClient?: ((url: any, options?: Options | undefined) => Promise<{ status: number; headers: Headers; body: string; json: any; }>) | undefined) => DataProvider'.  TS2339

   6 |         if (resource !== 'posts' || !params.data.pictures) {
   7 |             // fallback to the default implementation
>  8 |             return dataProvider.update(resource, params);
     |                                 ^
   9 |         }
  10 |         /**
  11 |          * For posts update only, convert uploaded image in base 64 and attach it to

[fzaninotto]

This is not bug, check the documentation or wait for someone to give you a hand on StackOverflow.

[g3n35i5]

@fzaninotto First of all, thank you for your answer. Could you briefly explain to me why it is not a bug (or faulty or incomplete documentation) if I took the code from the documentation without any changes and it does not work?

[fzaninotto]

Sorry, you're right, the documentation is wrong. I'll mark it as a documentation bug.

[g3n35i5]

Great, thank you very much!