Hotel Reservation MVC Example - JavaScript/Python

JavaScript, Expressjs, MVC frontend, Memcached, Python, FastAPI, GraphQL, AsyncPG, Postgres

This example contains a frontend and backend:

• The frontend is an Express application using an MVC architecture and Pug + Bootstrap4 for view templating.
• The backend is a GraphQL API providing the ability to create, delete, and list reservatios plus available rooms for a given date range.

React Javascript and Typescript versions of this same idea are available.

Booked reservations are listed via the API. Each reservation request were processed in the order provided as if they were real-time requests. The following rules are observed:

Context:

• When a room is reserved, it cannot be reserved by another guest on overlapping dates.
• Whenever there are multiple available rooms for a request, the room with the lower final price is assigned.
• Whenever a request is made for a single room, a double bed room may be assigned (if no single is available?).
• Smokers are not placed in non-smoking rooms.
• Non-smokers are not placed in allowed smoking rooms.
• Final price for reservations are determined by daily price * num of days requested, plus the cleaning fee.

Web UI Usage:

API Usage:

Example usage via curl:

# First, grab an access token provided by the API
ACCESS_TOKEN=$(curl -s -X POST \
  -H 'accept: application/json' \
  -H 'Content-Type: application/x-www-form-urlencoded' \
  -d 'grant_type=password&username=example-user&password=example-user' \
  'http://localhost:8080/token' | jq -r '.access_token')

# List all existing booked reservations
curl http://localhost:$API_PORT/development/graphql \
    -H 'Content-Type: application/json' \
    -H "Authorization: Bearer ${ACCESS_TOKEN}" \
    -d '{"query": "query { getAllReservations { reservations { room_id checkin_date checkout_date  } } }"}'

# Create a new reservation
# Note: if there is an overlap, you'll see a 
#   'Reservation dates overlap with an existing reservation' error message
# To see the aforementioned error, run this mutation a multiple times
curl http://localhost:$API_PORT/development/graphql \
    -H 'Content-Type: application/json' \
    -H "Authorization: Bearer ${ACCESS_TOKEN}" \
    -d '{ "query": "mutation { createReservation( input: { room_id: \"91754a14-4885-4200-a052-e4042431ffb8\", checkin_date: \"2023-12-31\", checkout_date: \"2024-01-02\"  }) { success errors reservation { id room_id checkin_date checkout_date total_charge } } }" }'

# List Available Rooms for a given date range
curl http://localhost:$API_PORT/development/graphql \
    -H 'Content-Type: application/json' \
    -H "Authorization: Bearer ${ACCESS_TOKEN}" \
    -d '{"query": "query { getAvailableRooms( input: { checkin_date: \"2023-12-31\", checkout_date: \"2024-01-02\" }) { success errors rooms { id num_beds allow_smoking daily_rate cleaning_fee } } }" }'

Open API UI Usage:

Navigate to http://localhost:$API_PORT/docs.

Table of Contents:

• Prerequisites
• Getting Started
  • Install Python Packages
  • Install Node.js Packages
  • Create the Database
• Development
• Testing
• TODO
• License

Prerequisites

To run the service, you will need to install the following tools.

• Python
• NodeJS
• Docker

The below are optional but highly recommended:

• nvm - Used to manage NodeJS versions.
• Direnv - Used to manage environment variables.

Getting Started

First, we'll need to set up our environment variables. You can do this by either any of the methods mentioned in /tools/ENV.md but I recommend using Direnv.

Install Python Packages

Next, execute the following in your terminal:

python -m venv venv
source venv/bin/activate
pip install --upgrade pip 
pip install -r requirements.txt

Install Node.js Packages

Execute the following within your terminal:

nvm use             # To eliminate any issues, install/use the version listed in .nvmrc. 
npm i               # install the packages needed for project 

Create the database

Finally, let's create and seed the database and our Reservations and Rooms tables:

# Create the database and seed it
NODE_ENV=development | npm run refresh && npm run seed

During development, you can just execute npm run dev:db-baseline to refresh the database back to the original seed data.

Development

To run both the frontend and backend concurrently:

docker-compose up -d  # runs the database in the background
npm run dev

Also, you just execute the backend via npm run dev:backend. to verify the backend is working:

curl http://localhost:$API_PORT/$ENV/about

You can also acces the Ariadne GraphiQL (interactive test playground) instance at http://localhost:$API_PORT/$ENV/graphql.

Testing

The frontend utilizes Jest. To run these tests, simply execute npm run test:frontend.

The backend tests organized for improved readability and comprehension. These tests are segmented into individual files, a structure that simplifies the testing process and enhances accessibility. While individual preferences may vary, this is my chosen approach for managing tests in this project.

To run these tests, simply execute npm run test:backend.

Containerization

Building the Backend Container

docker build backend/. -t acme-hotel-example-backend:latest \
    --build-arg RESERVATION_PORT="80" \
    --build-arg ENV="${ENV}" \
    --build-arg IS_DEBUG="${IS_DEBUG}" \
    --build-arg SECRET_KEY="$SECRET_KEY" \
    --build-arg REFRESH_SECRET_KEY="$REFRESH_SECRET_KEY" \
    --build-arg PG_URL="$PG_URL"

# finally, to run a named container
docker run --name backend-dev -p 8000:80 acme-hotel-example-backend`

To verify the environment variables set, you can execute the following on the named container by:

CONTAINER_ID=$(docker ps -qf "name=backend-dev" -n 1)

# this will display the container's environment variables in console
docker exec $CONTAINER_ID printenv   

If you need to re-create the container with the same name, do docker rm (i.e., backend-dev) first.

License

License information can be found here