Simple Calculator

This is a simple calculator implementing the DMAS part of BODMAS. It has been primarily designed around providing a quick result as you type a calculation in the input but it also includes a simple set of buttons to enter calculations.

Operators

You can use the following operators:

• / - Divide
• * - Multiply
• + - Add
• - - Subtract

Example calculations

The calculator can support calculations like:

• 2 + 2
• 2 + 3 * 4
• 2 * 2 * 2 * 2 * 2
• 4 - 6 + 2 * 5 / 3

Installation

This project depends on having Node JS (https://nodejs.org/en/) and Yarn (https://classic.yarnpkg.com/en/) installed on the system.

Install the necessary dependencies using yarn.

yarn

Test

This performs lint, prettier and unit tests

yarn test

You can run the unit tests alone using

yarn test:unit

You can watch unit tests using

yarn test:unit --watch

Development Server

yarn start

Production Build

This build the project into the ./dist directory

NODE_ENV=production yarn build

CI Pipeline

It's common to break these out using CI pipeline definition files depending on the CI/CD platform they are often in a yaml format (Groovy in the case of Jenkins) so that the different stages can have their own metrics.

// stage test
yarn test

// stage build
NODE_ENV=production yarn build

// stage publish
// Publish test result and coverage
// coverage results will be in the ./coverage folder
// usually I would use the jest junit reporter to send test results

// stage clean
yarn clean