ReactJS/TypeScript and Kotlin assignment

This repo is used for home assignment as part of the hiring process at Bettermarks.

We hope that you would be able to finish this assignment within two hours.

If there are any questions/problems while you are working on it, please ask them via mail or create an issue in the repo.

Objective: Create a small equation validator web application using Kotlin, ReactJS and TypeScript.

Requirements

• OpenJDK 18
• Kotlin SDK
• NodeJS v16

Step 0 - Run the code

• The app folder contains the ReactJS and TypeScript code base

• The equation-validator folder contains the Kotlin code base

• In the app folder, make sure the react app is running correctly:

node -v
# > v16
npm i && npm start

Your app should run on localhost:8080

• In the equation-validator folder

  • build the kotlin app:

    java --version
    # > openjdk 18 ....
    ./gradlew build

  • run the kotlin app using the native CLI executable:

    ./build/bin/native/debugExecutable/equation-validator.kexe
    # > Enter an equation (like a + b = c):
    # > 1 + 2 = 3
    # > FIXME

Step 1 - Kotlin: implement the equation validator

• Objective: Given a text input representing a simple equation, return if the equation is valid or not.

Only equations of type a + b = c are accepted.

Examples:

Input: "1 + 2 = 3"
Response: "valid"

Input: "1 + 2 = 5"
Response: "invalid"

Input: "not an equation"
Response: "syntax error"

Input: "1 + 2 + 3 = 6"
Response: "syntax error"

Input: "1 - 2 = 3"
Response: "syntax error" 

You can code your validator inside equation-validator/src/commonMain/kotlin/Validator.kt

Step 2 - React: Integrate the validator JavaScript library

• Objective: Use the equation validator from the ReactJS/TypeScript app.

The gradle configuration is already configured to build the equation-validator as JavaScript bundle in equation-validator/build/js/packages/equation-validator

• You can include the equation-validator module like:

# from app/
npm i --save ../equation-validator/build/js/packages/equation-validator

• and import {validateEquation} from 'equation-validator'; to import the equation-validator (compiled from the fun validate() { ... } in kotlin)

• You do not need any specific style, just add the return of the validateEquation function inside a <span></span> html tag after the ?

Step 3 - Submit your results

1. Commit and push all your changes to a new branch
2. Create a pull request on main with your results from GitHub In case you ar not familiar with creating pull requests, please follow the official instructions provided by GitHub.
3. Add your contact person as a reviewer.