Developing a dynamic map that contains method values returning observables that may throw TypeScript errors

Curious as to why my code is throwing an error. I have specified a type for the method

type ReturnObsFunc = (str?: string) => Observable<any>;

I am trying to create a map using a Map Object, but it seems to be not working correctly

  private getFilterSource$(filterType: FilterType): Observable<any> {
    const sourceMap = new Map<FilterType, AnotherFunc>([
      [FilterType.SubClient, this._filtersService.getClients$],
      [FilterType.Product, this._filtersService.getProducts$],
    ]);

    return sourceMap.get(filterType);

    //The error says: Type 'ReturnObsFunc' is missing certain properties expected by 'Observable<any>'
  }

Although there is a solution with object map, I am interested in finding out if it can be achieved using Map.

  private getFilterSource$(filterType: FilterType): Observable<any> {
    const sourceMap = {
      [FilterType.SubClient]: this._filtersService.getClients$,
      [FilterType.Product]: this._filtersService.getProducts$,
    };

    return sourceMap[filterType]
  }

Answer №1

Ah-ha, I've figured it out - the correct solution is for getFilterSource$ to return ReturnObsFunc instead of Observable. It seems so clear now.

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