findOrCreate mongoose typescript plugin

gistfile1.txt

import { Document, Model, Schema } from 'mongoose';
import { ObjectID } from 'bson';

/**
 * Find or create mongoose static function creator
 */

export type WithFindOrCreate<T extends Document> = {
  findOrCreate: (id?: string | ObjectID | null) => T;
};

export function findOrCreateFactory<T extends Model<any>>() {
  return async function(this: T, id?: string | ObjectID | null) {

    if (!id || !ObjectID.isValid(id)) {
      return new this();
    }

    const $id = new ObjectID(id);
    const item = await this.findById($id);
    return item ? item : new this();
  };
}

export function withFindOrCreate<T extends Model<any>>(schema: Schema) {
  schema.statics.findOrCreate = findOrCreateFactory<T>();
  return schema;
}