I am new to typescript and I'm trying to understand why I'm getting the following errors.

Type 'FindCursor<WithId>' is missing the following properties from type 'Topping': name, priceCents

and

Argument of type 'Promise' is not assignable to parameter of type 'void'

public async getToppingsData(ID: String): Promise<Topping> {
    const data = await this.collection.find({ _id: ID });
    if (data === null || data === undefined) {
      throw new Error(`Could not find ${ID}`);
    }

    const toppingData: Topping = data;

    return toToppingObject(toppingData);
  }

  public async getToppingsByIds(toppingIds: String[]): Promise<String[]> {
    toppingIds.map((id) => {
      const toppingArray = [];
      toppingArray.push(this.getToppingsData(id));
      const toppingNames = toppingArray.map((topping) => {
        toppingNames.push(topping);
      });
      return toppingNames;
    });
  }

here is the toPizzaObject function

import { Document } from 'mongodb';
import { Pizza } from '../application/providers/pizzas/pizza.provider.types';
import { ObjectId } from 'bson';

interface PizzaDocument extends Document, Omit<Pizza, 'toppings' | 'id'> {
  toppingIds: ObjectId[];
}

const toPizzaObject = (pizza: PizzaDocument): Pizza => {
  return {
    id: pizza._id.toHexString(),
    name: pizza.name,
    description: pizza.description,
    toppings: pizza.toppingIds.map((toppingId) => toppingId.toHexString()),
    imgSrc: pizza.imgSrc,
  };
};

export { PizzaDocument, toPizzaObject };

CodePudding user response：

You messed up your map(), your were returning nothing, hence the void. Also you were not handle the Promise correctly, the return type wasn't matching.

Here is a suggestion:

  public async getToppingsByIds(toppingIds: String[]): Promise<String[]> {
    const toppingArray = [];
    for (let id of toppingIds) {
      const data = await this.getToppingsData(id);
      toppingArray.push(data);
    }
    const toppingNames = toppingArray.map((topping) => {
      return topping
    });
    return toppingNames
  }

PS: await can't be used on map/forEach(), that's why there is a traditional for-loop.