Saturday, January 26, 2019

Node Express with TypeScript

This walkthrough is intended to help you convert a standard Node Express application so that it uses TypeScript instead.

Install TypeScript globally:

npm install typescript -g

Let us create a directory simply to play around and understand how TypeScript works:

mkdir tsprimer
cd tsprimer
code .

Create a file named greeter.ts and add to it the following code:

function greeter(person) {
    return "Hello, " + person;
let user = "Jane Bond";

To trandspile the app, type:

tsc greeter.ts

This transpiles the app to greeter.js, which gets created in the same directory. Run the application with:

node greeter.js

Let us modify greeter.ts so that it uses strong type checking. Create a file named person.ts and add to it the following Person interface:

export interface Person {
    firstName: string;
    lastName: string;

Add a file named greeterPerson.ts that uses the Person interface with the following code:

import {Person} from './person';
function greeter(person: Person) : string{
    return "Hello, " + person.firstName + " " + person.lastName;
let person : Person = { firstName: "Jane", lastName: "Bond" };

Transpile the app with tsc greeterPerson.ts and run it with:

node greeterPerson.js

Create a file named student.ts to hold a Student class. The code is:

export class Student {
    fullName: string;
    constructor(public firstName: string, public middleInitial: string, public lastName: string) {
        this.fullName = firstName + " " + middleInitial + " " + lastName;
    public getFullName = () : string => {
        return this.fullName;

Notice the instance variable fullName, constructor and method getFullName(). Create a greeter file named greeterStudent.ts that uses the Student class as shown below:

import {Student} from './student';
let student  = new Student("Jane","M.","Bond" );

Transpile & run the application.

TS with Node Express
Go to the parent directory with:

cd ..

create a new directory named tsexpress and go into that directory:

mkdir tsexpress
cd tsexpress

Let us initialize a node project in the current directory with:

npm init

Let’s now install the typescript package locally with:

npm install typescript --save-dev

Open the current directory in Visual Studio Code.

Inside our package.json, add a script called tsc:

"scripts": {
    "tsc": "tsc"

This modification allows us to call TypeScript functions from the command line in the project’s folder.

Run the following command to initialize the typescript project by creating the tsconfig.json file.

npm run tsc -- --init

Edit tsconfig.json, uncomment outDir setting so that it looks like this:

"outDir": "./build",

Also, make sure you have these additional settings in tsconfig.json:

    "target": "es5", 
    "module": "commonjs",
    "sourceMap": true, 
    "strict": true,
    "pretty": true,
    "moduleResolution": "node",
    "baseUrl": "./app",
    "esModuleInterop": true

Add this to the bottom of tsconfig.json:

  "include": [
  "exclude": [

Installing express.js

Run the following command:

npm install express --save

Express and Typescript packages are independent. The consequence of this is that Typescript does not “know” types of Express classes. Run this specific npm package for the Typescript to recognize the Express class types.

npm install @types/express --save

Let us add a very simple Hello World Node Express application file. Create a folder named app and inside the app directory create a file named app.ts with this content:

// app/app.ts
import express = require('express');

// Create a new express application instance
const app: express.Application = express();

app.get('/', function (req, res) {
  res.send('Hello World!');

app.listen(3000, function () {
  console.log('Example app listening on port 3000!');

To transpile your first TypeScript Node Express app, run the following command in the root directory of your application:

npm run tsc

This command automatically created the build folder and adds to it the transpiled app.js file.


 To run the application in build/app.js, type:

node build/app.js

Point your browser to http://localhost:3000. You should see the following:

Running TypeScript without transpiling
You can run TypeScript code directly with the ts-node package.

This package is recommended for development purposes only. To make the final deployment to production, always use the JavaScript version of your project.

The ts-node is already included as a dependency on another package, ts-node-dev. After installing ts-node-dev we can run commands that restarts the server whenever a project file changes. Install  ts-node-dev as follows:

npm install ts-node-dev --save-dev

Add the following two script lines into the package.json file:

"dev": "ts-node-dev --respawn --transpileOnly ./app/app.ts",
"prod": "tsc && node ./build/app.js"

To start the development environment:

npm run dev

 To run the server in production mode:

npm run prod

Pure TypeScript Classes
So far in our Node/Express sample application, we are not really using proper TypeScript syntax. Let’s start making use of the powerful TypeScript platform.

Create a file named server.ts in the app folder and add to it the following code:

// app/server.ts
import app from "./app";
const PORT = 3000;

app.listen(PORT, () => {
    console.log('Express server listening on port ' + PORT);

In package.json:

change app.js                 TO              server.js
change app.ts                 TO             server.ts

Create a folder named routes under app and add to it the following index.ts file:

// /app/routes/index.ts
import {Request, Response} from "express";
export class Routes { 
    public routes(app: any): void { 
            .get((req: Request, res: Response) => {            
                res.status(200).send('Hello World!');

Replace code in app/app.ts with following code:

// app/app.ts
import express from "express";
import bodyParser from "body-parser";
import { Routes } from "./routes";

class App {
    public app: express.Application;
    public routePrv: Routes = new Routes();

    constructor() { = express();

    private config(): void {, res, next) {
            res.header("Access-Control-Allow-Origin", "*");         
            res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");         
            res.setHeader('Access-Control-Allow-Methods', 'GET, POST, OPTIONS, PUT, PATCH, DELETE');

        // support application/json type post data;
        //support application/x-www-form-urlencoded post data{ extended: false }));
export default new App().app;

Test the application in dev mode by running:

npm run dev 

Then point your browser to http://localhost:3000. You should see Hello World in the browser.

Test same as above in production mode by running:

npm run prod

Using mongoose

Mongoose is an Object Data Modeling (ODM) library for MongoDB and Node.js. In this section we will talk get our application to conntect with a MopngoDB database using the Mongoose driver. It is assumed that you have a MongoDB database running on your development computer and listening on port 27017.

Install these mongoose packages:

npm install mongoose –save
npm install @types/mongoose --save

Create a folder named models under app and add to it a file named student.ts with the following code:

//   /app/models/student.ts
import mongoose from 'mongoose'; 
const Schema = mongoose.Schema;
// create a schema
export const StudentSchema = new Schema({
    FirstName: {
        type: String,
        required: true
    LastName: {
        type: String,
        required: true
    School: {
        type: String,
        required: true
    StartDate: {
        type: Date,
        required: true

Create a folder called controllers under app and add to it a file named studentController.ts with this code:

//   /app/controllers/studentController.ts
import * as mongoose from 'mongoose';
import { StudentSchema } from '../models/student';
import { Request, Response } from 'express';

const StudentMongooseModel = mongoose.model('Student', StudentSchema);

export class StudentController { 

    public addNewStudent (req: Request, res: Response) {                
        let newStudent = new StudentMongooseModel(req.body);

        let newStudent = new StudentMongooseModel({
            "FirstName": "Tom",
            "LastName": "Baker",
            "School": "45 River Road",
            "StartDate": "2001-11-17T19:23:15.118Z"
  , data) => {
            if (err){

    public getStudents (req: Request, res: Response) {           
        StudentMongooseModel.find({}, (err, data) => {
            if (err){

    public getStudentById (req: Request, res: Response) {           
        StudentMongooseModel.findById(req.params.studentId, (err, data) => {
            if (err){

    public updateStudent (req: Request, res: Response) {           
        StudentMongooseModel.findOneAndUpdate({ _id: req.params.studentId }, req.body, { new: true }, 
            (err, data) => {
            if (err){

    public deleteStudent (req: Request, res: Response) {           
        StudentMongooseModel.findOneAndRemove({ _id: req.params.studentId }, (err, data) => {
            if (err){
            res.json({ message: 'Successfully deleted student!'});

    public generateDummyData (req: Request, res: Response) {     
        var data = [
            "StartDate": new Date("2012-02-20T08:30:00")
            "StartDate": new Date("2018-03-17T17:32:00")
            "School":"Political Science",
            "StartDate": new Date("2014-06-20T08:30:00")
            "StartDate": new Date("2014-06-20T08:30:00")
            "School":"Environmental Sciences",
            "StartDate": new Date("2017-10-16T17:32:00")
        StudentMongooseModel.collection.insert(data, function (err, docs) { 
            if (err){
            res.json({ message: 'Successfully generated 5 sample documents!'});

Add this instance variable to the Routes class in routes/index.ts and resolve it by importing the appropriate module:

studentController: StudentController = new StudentController();

Add these routes to routes/index.ts:

        // Get all students

        // Create a new student

        // get a specific student

        // update a specific student
        // delete a specific student
        // generate dummy data

Notice that the last route, /api/dummy, which is for generating dummy data.
Back in /app/app.ts, import mongoose with:

import mongoose from "mongoose";

Add this method to /app/app.ts:

    private mongoSetup(): void{
        mongoose.connect('mongodb://localhost:27017/school', {})
        .then(() => console.log('connection successful'))
        .catch((err) => console.error(err));

In the constructor of /app/app.ts, call the above method with:


Start the server with:

npm run dev

In your browser, point to http://localhost:3000. You should see Hello World.

Next, point your browser to http://localhost:3000/api/dummy. This should create sample data.

Use URL http://localhost:3000/api/students to see the sample data that was jiust created.

Saturday, January 19, 2019

Continuous Integration and deployment of Angular App with Azure DevOps


This document describes processes and best practices for an end-to-end continuous integration and deployment of an Angular Application.
  •     Node.js, npm and angular-cli are installed on dev computer
  •      Angular is installed on your computer: npm install -g @angular/cli
  •      GIT is installed on the dev computer
  •      Developer has access to an account on Azure DevOps at
  •      Developer has an account on Azure (

Note: It is best if both your DevOps & Azure accounts use the same Microsoft account credentials.

Creating a simple Angular CLI app on dev computer:

Create an angular app using angular-cli:
ng new ngware
cd ngware
ng serve
Point your browser to http://localhost:4200 and you should see the following:

Web.config file

For Angular’s routing to work smoothly on Azure, it is necessary to have a web.config file. Therefore, stop the server and create a web.config file in the src directory and add to it the following markup:
<?xml version="1.0"?>
         <rule name="Angular Routes" stopProcessing="true">
            <match url=".*" />
            <conditions logicalGrouping="MatchAll">
               <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
               <add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />
               <add input="{REQUEST_URI}" pattern="^/(api)" negate="true" />
            <action type="Rewrite" url="/" />
To enable the web.config file to be packaged with production code, edit the angular.json file and add ‘web.config’ to assets, as follows:
. . . . .
"assets": [
. . . . .

Build app

Build the app using the following command:
ng build --prod
This produces the production version of the application in the dist/ngware folder. To test the trans-piled version of the app, start the server then point your browser to http://localhost:4200/dist/ngware. You should see the same app as before, this time it is being served from production code.

Azure DevOps

Azure-DevOps is Microsoft’s DevOps platform. Login into Azure-DevOps and create a new project. In my case I created a new project named ngware.

Once the project is created in Azure-DevOps, it is time for us to push our code using Git. Copy the address of the Git repo so that we can use it to sync our code. Click on Repos on the left-side then note the Git commands.
Back at your computer, stop the server and run the following commands from your command prompt to push the code into your projects Azure-DevOps git repository:
git init
git add .
git commit -m "first commit"
git remote add origin {your-git-url-here}
git push -u origin master
You may be asked to login into Azure-DevOps.
Once your code has uploaded to Azure-DevOps, Click on Repos on the left-side in Azure-DevOps to verify that your code has indeed uploaded to Azure-DevOps:
The code will look like this:

Building the code in Azure-DevOps

The same steps that we carried out to build our app in the development computer will be translated into tasks in Azure-DevOps. To build our app, choose: Pipelines >> Builds on the left side:
Click on the blue “New pipeline” button:

On the “Select a source” dialog, accept the defaults and click on the Continue button at the bottom:

On the “Select a template” dialog, scroll to the very bottom and click on “Empty pipeline” then click on the blue Apply button.

Give the build a proper name (like: Build Angular App) then select “Hosted” under Agent pool:

Next, click the “+” to add a task:

In the filter, enter npm. Highlight the npm task then click on Add. Add the following five tasks:
Node Tool Installer
Archive Files
Publish Build Artifacts
This is what the series of tasks will look like:

Customize each task as follows:

1) Use Node 6.x

Display name
Use Node 10.x
Version Spec

2) npm install

This task runs the command “npm install” to install node packages. You do not need to make any changes to this task as it does exactly what we want it to do.

3) npm install

This task will run “npm run build” command, which is essentially a script in our package.json file:
  "scripts": {
    "ng": "ng",
    "start": "ng serve",
    "build": "ng build",
    "test": "ng test",
    "lint": "ng lint",
    "e2e": "ng e2e"
Configure the npm  task like this:
Display name
Build angular app
Command and arguments
Run build --prod

4) Archive $(Build.BinariesDirectory)

This task is responsible for creating a zip file containing all the files, created by the previous task, that reside in the dist/ngware directory.
Display name
Archive production files
Root folder or file to archive
Prepend root folder name to archive paths

Note: Copy the value of the ‘Archive file to create’ into the clipboard because we will be using it in the next task.
5) Publish Artifact: drop
Next, we will publish the zip we created in the last step.
Path to publish
Paste this from the value you copied into the clipboard in the previous task.

That’s it for all our steps. Let’s run the build! Click on Save & Queue >> Save & Queue in the top menu.

On the next dialog, click on “Save & Queue”

Click on the build number link in the in the top left-side corner.

This will allow you to see progress of the build. When the build is completed without any errors, you will see a green “Build Succeeded” messages as shown below:


You can see the package that was created by selecting the blue Artifacts button on the top-right.

Download the drop folder to see what was created inside that directory.  Click on the three dots beside drop to download the zip file.

The file contains another numbered zip file that has the production files.

Continuous Integration

We will need to setup continuous integration so that whenever new code is committed, the build process is automatically kicked off. In the navigation at the top of the page, click on the build as shown:

Click “Edit” beside the bluer Queue button:

On the next page, click on “Triggers”:

Enable continuous integration by enabling the switch:

Click: Save & Queue >> Save:

On the next dialog, add a comment then click Save:

Creating Release

Log into Azure and create a web app.

Back in Azure-DevOps, create a release definition by clicking on Pipelines >> Releases on the left side. Click on the blue “New pipeline” button in the middle of the page.

In the sliding “Select a template” dialog on the right-side, select “Azure App Service deployment” and click on the blue Apply button.

Click on the X in the corner of the right-side dialog to close it.

Select the first “Add an artifact” box.

On the right-side dialog, select the build we just created for “Source (build pipeline)”. Accept all other default values. Then click on the Add button.

In order to enable continuous deployment, click on the thunderbolt icon in the top-right corner of the first box.

A dialog opens on the right side. Enable the “Continuous deployment trigger”.

Click on the second box’s “1 job 1 task” link.

Select your Azure subscription then click on the blue Authorize button.

NOTE: You may need to enable popup windows for in your browser.
Once you are authorized with, select App type to be Web App. Under App service name, choose the web app that you created earlier on the Azure portal. The final state of the dialog would look similar top the following:

Click Save at the top:

You can enter a comment in the following dialog then click on OK.

When the “+ Release” link at the top lights up, click on Release >> Create a release.

Choose the stage and build version on the next dialog then click on Create.

The release process is about to start. Click on the release link on the top side.

When you click on the second box, you will see a Deploy button. Click on the Deploy button to start the deployment.

Click on the Deploy button again when you experience the following dialog.

Wait until you see an “In progress” message in that box. Click on it when it appears to see progress of the deployment. If all goes well, all tasks will show succeeded in green.

What is left is for us to prove that the application has indeed deployed to azure. In my case, I pointed my browser to and hit the following website.

Make a change to your source code, like change the background color, and push your code to the Git repo on Azure-DevOps. The build and release processes will be automatically triggered and you should find your changes deployed in less than five minutes.