Express.js Starter App

Concept

This project shows some basic usage of Express.js features, including:

handling incoming HTTP requests using express routes
exploring the purpose of middleware and how it works
debugging express apps using morgan and Postman
handling data included in HTTP POST requests
handling file uploads using multer
making requests from express to external APIs with axios and serving the data to the client
setting environmental variables using dotenv
use of a .gitignore file to exclude 3rd-party code and autogenerated files from version control tracking
use of a package.json with npm to track dependencies and streamline installation.

Many of the features of Express exhibited in this project are explained at a high level in this prepared lecture presentation.

Intentional exclusions

There are some common practices that we have not included here, since we believe they are distraction's from a beginner's ability to master React's code patterns.

inclusion of any front-end code
inclusion of user account registration or log in functionality
inclusion of unit testing modules, like mocha and chaai
inclusion of any database
use of express-router for better-organizing routes

Available Scripts

In the project directory, you can run:

`npm install` - install dependencies

Installs all the dependencies listed in the package.json configuration file. This is necessary before running the app, since the 3rd-party dependency code is excluded from version control by the .gitignore git settings file.

`nodemon server` - start the server locally

Start up the web server application using nodemon, which will stop and restart the app anytime there is a code change. The server will be available on port 3000 of the local computer at the URL, http://localhost:3000.

Server API End-Points

This server code sets up routes for several API end-points - URLs to which a client can make requests. Except where indicated, the server accepts GET requests to these routes.

The example routes include:

/ - a route for the "root" document - usually the home page, but in this case a simple text response.
/html-example - a route that shows how to return a simple HTML document.
/static/css/main.css - a route that servers as an example of servnig a static file that does not need dynamic server logic.
/json-example - a route that shows how the server can respond with a JSON document.
/middleware-example - a route that exhibits the concept of middleware.
/post-example - a route that accepts POST requests with some content the server expects the client to send in the body of the request.
/upload-example - a route that accepts a POST request with one or more files in the request that the client uploads to the server.
/proxy-example - a route that causes the server to make a request to a different API and then respond to the client with the data received from that API.
/dotenv-example - a route that shows how a server can use the dotenv module to load environmental variables from a file named .env into Javascript code.
/parameter-example/22 - a route that shows an example of how parts of the route URL - in this case the number 22 - can be parameterized and accessed in code.

Running the server

Testing the routes

It is possible to try out the routes directly in a web browser. However, it is often more convenient to use an API-testing tool like Postman to test out the server API end-points.

Import the test file named express-js-starter-app.postman_collection.json into Postman to test out the API end-points.

ZiyiWang716/express-js-starter-app