Typescript fully typed mongoose workflow incl. virtuals, statics and hooks

gistfile1.txt

import { Document, model, Model, Schema } from 'mongoose';
import { withFindOrCreate, WithFindOrCreate } from '../utils/findOrCreate';
import { NutrientUnitInstance, NutrientUnitModel } from '../NutrientUnit/NutrientUnit';
import { ObjectID } from 'bson';

/**
 * Nutrient (e.g. calcium)
 */

export interface Nutrient {
  code: string;
  title: string;
  displayUnitCode: string;
  /**
   * @deprecated
   */
  displayUnitId: ObjectID;
}

export type NutrientInstance = Nutrient & Document & {
  displayUnit: Promise<NutrientUnitInstance>;
};

export type NutrientInstanceStatic = Model<NutrientInstance> &
  WithFindOrCreate<NutrientInstance>;

// findOrCreate adds a typed static method on the Model
// https://gist.github.com/rasdaniil/6d411a4f6441b5548eeadadfd1f7b60a

export const nutrientSchema = withFindOrCreate(
  new Schema({
    code: {
      type: String,
      index: true,
      required: true,
      lowercase: true,
    },

    title: {
      type: String,
      required: true,
    },

    displayUnitCode: {
      type: String,
      required: true,
    },

    displayUnitId: {
      type: String,
    }

  }),
);

// @ts-ignore
nutrientSchema.post('init', async function(this: NutrientInstance) {
  // noinspection JSDeprecatedSymbols
  if (!this.displayUnitCode && this.displayUnitId) {
    const unit = await NutrientUnitModel.findById(this.displayUnitId);
    if (unit) {
      this.displayUnitCode = unit.code;
      await this.save();
    }
  }
});

nutrientSchema.virtual('displayUnit').get(async function(this: NutrientInstance) {

  if (!this.displayUnitCode) {
    return Promise.resolve(null);
  }

  return await NutrientUnitModel.findOne({ code: this.displayUnitCode });
});


export const NutrientModel = model<NutrientInstance>(
  'Nutrient',
  nutrientSchema,
  'nutrient',
) as NutrientInstanceStatic;