orders.web.ch.gov.uk

Overview

The aim of this template is to give you a head start in setting up a new web application for Companies House.

The template uses Express, TypeScript and the GovUK Frontend toolkit to set up a simple example of a web application that runs on NodeJS.

You can create a new project from this template by clicking the Use this template button.

Contents

• Quick start
• Prerequisites
• Running the server
• Static assets
• Compiling the application
• Linting
• Testing

Quick start

If you are familiar with NodeJS development and already have it installed, simply run the init make task

make init

And then start the application

npm start

Then go to http://localhost:3000.

Prerequisites

You are going to need a few things to begin. Firstly, NodeJS. There are a few ways to install it.

• Official installer
• Node Version Manager
• Homebrew

Node version manager allows you to install multiple versions side by side on the host machine.

Running the server

There are two ways to run the server in development. You run it in normal mode;

npm start

Or, automatically reload the server once you make changes to source code;

npm start:watch

Compiling the application

TypeScript compiles down the JavaScript code that eventually gets run via NodeJS. The build npm task will write the JavaScript to the dist folder.

npm run build

It is this code that gets run in production.

Linting

TSLint is used to perform static analysis on code style.

npm run lint

Testing

Tests can be found in the directory src/test. The framework used is Jest along with Supertest to dispatch handlers that can have assertions made against the responses. Execute the following to run the tests;

npm t

Health check endpoint

Path	Method	Description
/orders-web/health	GET	Returns HTTP OK (200) to indicate a healthy application instance.

Health check implementation note

• The healthcheck endpoint uses the express-actuator package. This means the app also provides /orders-web/info and /orders-web/metrics endpoints. These should probably not be exposed.