Example typescript pattern for defining a view using 'mongoose-decorators-ts'

common.ts

export const readOnlyExcludeKeysModel = <const>[
    'watch', 'bulkWrite', 'create', 'createCollection',
    'syncIndexes', 'listIndexes', 'ensureIndexes',
    'createIndexes', 'findByIdAndRemove', 'findByIdAndDelete',
    'findByIdAndUpdate', 'findOneAndRemove', 'findOneAndDelete',
    'findOneAndUpdate', 'insertMany', 'remove', 'deleteOne',
    'deleteMany', 'replaceOne', 'update', 'updateMany', 'updateOne',
];
export type readOnlyExcludeKeysModel = typeof readOnlyExcludeKeysModel[number];
export const readOnlyExcludeKeysDoc = <const>[
    'remove', 'save', 'set', 'overwrite', 'isModified', 'isDirectModified',
];
export type readOnlyExcludeKeysDoc = typeof readOnlyExcludeKeysDoc[number];

ulsActiveCallsigns.ts

import { Db } from "mongodb";
import mongoose from "mongoose";
import { schemaDef, ModelFromSchemaDef, field } from "mongoose-decorators-ts";
import { ULSEntityModel, ULSLicenseModel, ULSAmateurModel } from "../uls";
import { readOnlyExcludeKeysModel } from "./common";

// Pipeline
const pipeline = [
    { $match: { applicant_type: 'Individual', } },
    { $project: {
        "u_id" : 1,
        "licensee_id" : 1,
        "callsign": 1,
        "first_name" : 1,
        "middle_initial" : 1,
        "last_name" : 1,
        "suffix" : 1,
        "address": 1,
        "city" : 1,
        "state" : 1,
        "zip" : 1,
        "frn" : 1,
    } },
    { $lookup: {
        "from" : "ulslicenses",
        "let" : { "uid" : "$u_id" },
        "pipeline" : [ {
                "$match" : {
                    "$expr" : { "$eq" : [ "$u_id", "$$uid" ] },
                    "license_status" : "Active"
                }
            }, {
                "$project" : {
                    "_id": 0,
                    "license_status" : 1,
                    "grant_date" : 1,
                    "expired_date" : 1,
                    "effective_date" : 1,
                    "cancellation_date" : 1,
                }
            }
        ], "as" : "ulsLicense"
    } },
    { $lookup: {
        "from" : "ulsamateurs",
        "let" : { "uid" : "$u_id" },
        "pipeline" : [ {
                "$match" : {
                    "$expr" : { "$eq" : [ "$u_id", "$$uid" ] }
                }
            }, {
                "$project" : {
                    "_id": 0,
                    "license_class" : 1,
                    "prev_license_class": 1,
                }
            }
        ],
        "as" : "ulsAmateur"
    } },
    { $unwind: { path : "$ulsAmateur", } },
    { $unwind: { path : "$ulsLicense", } },
    {
        $addFields: {
            "license_status" : "$ulsLicense.license_status",
            "grant_date" : "$ulsLicense.grant_date",
            "expired_date" : "$ulsLicense.expired_date",
            "effective_date" : "$ulsLicense.effective_date",
            "license_class" : "$ulsAmateur.license_class",
            "prev_license_class" : "$ulsAmateur.prev_license_class"
        }
    },
    {
        $unset: ["ulsAmateur", "ulsLicense"],
    }
];

export async function register() {
    try {
        return await UlsActiveCallsignsModel.db.createCollection('ulsActiveCallsigns', {
            viewOn: 'ulsentities',
            pipeline,
        });
    } catch (err) {
        console.warn("Could not create ulsActiveCallsigns view:", err);
    }
}


@schemaDef({
    schemaOpts: {
        collection: 'ulsActiveCallsigns',
        id: false,
        autoIndex: false,
    }
})
class UlsActiveCallsigns {
    @field() u_id: ULSEntityModel['u_id'];
    @field() callsign: ULSEntityModel['callsign'];
    @field() licensee_id: ULSEntityModel['licensee_id'];
    @field() first_name: ULSEntityModel['first_name'];
    @field() middle_initial: ULSEntityModel['middle_initial'];
    @field() last_name: ULSEntityModel['last_name'];
    @field() suffix: ULSEntityModel['suffix'];
    @field() address: ULSEntityModel['address'];
    @field() city: ULSEntityModel['city'];
    @field() state: ULSEntityModel['state'];
    @field() zip: ULSEntityModel['zip'];
    @field() frn: ULSEntityModel['frn'];
    @field() license_status: ULSLicenseModel['license_status'];
    @field() grant_date: ULSLicenseModel['grant_date'];
    @field() expired_date: ULSLicenseModel['expired_date'];
    @field() effective_date: ULSLicenseModel['effective_date'];
    @field() license_class: ULSAmateurModel['license_class'];
    @field() prev_license_class: ULSAmateurModel['prev_license_class'];
}

const fullModel = ModelFromSchemaDef(UlsActiveCallsigns);

export const UlsActiveCallsignsModel: Omit<typeof fullModel, typeof readOnlyExcludeKeysModel[number]> = fullModel;
export type UlsActiveCallsignsModel = Omit<mongoose.Document<UlsActiveCallsigns>, typeof readOnlyExcludeKeysModel[number]>;

export default UlsActiveCallsignsModel;