Firebase functions Unit Testing

const admin = require('firebase-admin');
const functions = require('firebase-functions');

// for local dev.  You can use another if/else to depict local mode
if (process.env.USERDOMAIN === "YOURCOMPUTERNAME") {
    admin.initializeApp({ apiKey: "test"});
} else {
    admin.initializeApp();
}

// Subscribe to the notifications/* firestore path for create events
exports.handlePushNotification = functions.firestore.document("notifications/{docId}").onCreate(async (change: any, context: any) => {
    // initializing firestore and creating a batch
    const db = admin.firestore();
    const data = change.data();
    const notificationId = context.params.docId;
    const batch = db.batch();

    try {
        if (!data) {
            console.log("Could not find valid firestore doc for notification");
            return;
        }
        // making sure the notification doc has a valid recipient list
        if (data.recipientIds === undefined || data.recipientIds.length === 0) {
            console.log("Recipient Id list is either undefined or empty");
            return;
        }

        // fetching all the users who are on the recipient list
        const users: any[] = [];
        await Promise.all([...data.recipientIds.map(async(userId: string) => {
            const doc = await db.collection("users").doc(userId).get();
            const user = await doc.data()
            if (user) {
                users.push({...user, id: userId});
            }
        })]);

        // Grabbing all the users device tokens
        const tokens: string[] = [];
        users.forEach(user => {
            if (user.deviceIds && user.deviceIds.length > 0) {
                tokens.push(...user.deviceIds);
            }
        })

        // If we found no tokens, just exit since we can't send a notification without a token
        if (tokens.length <= 0) {
            console.log("No tokens to send notifications to")
            return;
        }

        // Sending the notification.  For failed tokens, we remove the token from the users doc
        const message: any = {
            data: data.data || {},
            tokens,
            notification: data.notification
        };
        await admin.messaging().sendEachForMulticast(message)
            .then(async (response: any) => {
                if (response.failureCount > 0) {
                    for (const resp of response.responses) {
                        const idx = response.responses.indexOf(resp);
                        if (!resp.success) {
                            const user = users.find(el => el.deviceIds && el.deviceIds.includes(tokens[idx]));
                            if (user) {
                                batch.update(db.collection("users").doc(user.id), {
                                    deviceIds: user.deviceIds.filter((el: string) => el !== tokens[idx])
                                });
                            }
                        }
                    }
                }
            });
    } catch(e) {
        console.log("Failed with error: ", e);
    } finally {
        // Committing any updates that we made in our try block along with deleting the doc once we are done
        batch.delete(db.collection('notifications').doc(notificationId));
        await batch.commit();
    }
});

const test = require('firebase-functions-test')({
    authDomain: "",
    projectId: "",
    storageBucket: "",
    messagingSenderId: ""
}, process.env.GOOGLE_APPLICATION_CREDENTIALS);

const assert = require("assert");

describe('Triggers', function () {
    let functionsToTest;

    // adds the functions to test
    before(function () {
        functionsToTest = require('../lib/index');
    });
    // cleans up firebase after each test
    after(function () {
        test.cleanup();
    });
    describe('Should handle a push notification doc', function () {
        it('It should return true', function (done) {
            const wrapped = test.wrap(functionsToTest.handlePushNotification);
            wrapped({
                    data: () => ({
                        recipientIds: ["2"]
                    })
                },
                {
                    params: {
                        docId: "test"
                    }
                }).then(() => {
                    done();
            });
        });
    });
});