akiutoslahti / calculus-demo-node

Simple web API to calculate base64 encoded math expressions

calculus-demo-node

Application

Latest build live in Heroku!

Send a base64 encoded math expression to https://calculus-demo.herokuapp.com/calculus?query=[expression] and application will calculate it for you and respond with JSON. Supported operators are: / * + - ( )

Example

Expression: 4 * 7 / 2 + 3
Expression in base64: NCAqIDcgLyAyICsgMw==
Query: https://calculus-demo.herokuapp.com/calculus?query=NCAqIDcgLyAyICsgMw==
Response:

HTTP/1.1 200 OK

{
  error: false,
  result: 17
}

In case of malformatted expression, application will attempt identify fault and responds:

HTTP/1.1 400 Bad Request

{
  error: true,
  message: [message depicting type of error]
}

Run application locally

First clone the project from github, change directory to cloned projects directory and then use either node or docker to run it.

git clone https://github.com/akiutoslahti/calculus-demo-node.git
cd calculus-demo-node

Node

Install dependencies

yarn install

To start and bind application to default port 3000

yarn start

To start and bind application to other port, e.g. 8080

PORT=8080 yarn start

Stop application with CTRL+C.

Docker

Application binds to localhost port 80 when started with docker. To change port you can change port definitions in docker-compose.yml

Start application with docker-compose

docker-compose up -d

Stop application with docker-compose

docker-compose down

Build stack and pipeline

Project is built using Node.js with Yarn dependency management. Travis CI is used for building and publishing image to Docker Hub, publishing test coverage results to codecov and deploying appication to Heroku. There is also a Dockerfile for building a docker image and a docker-compose file for running application on your own computer.

Development stack used in project

• node 10.14.2
• yarn 1.12.3
• docker ce 18.09.0
• docker-compose 1.23.2

Links

• Travis CI
• Codecov
• Docker Hub
• Heroku