Task: Implement a full-stack calculator

It is about implementing a full-stack calculator. Calculator needs to send all calculations into back-end, back-end should calculate the result and represent the result in front-end.

Must have.

1-Must use React hooks and TypeScript..

2-Everything should be typed from A to Z. No use of any, unknown, object and other similar types, where they can be known..

3-Must have unit tests, that cover all major edge cases for calculator.

4-Must be fully handling all special cases of calculator, like: division by zero, trying to do a math.

5-expression from unfinished float number e.g., “233.” etc..

6-All calculation process must be done in back-end..

7-Can't use libraries that do "safe evaluation" for you, like expr-eval or other..

8-Calls to the BE must be secure..

9-Must be able to handle the following math operators: %, /, *, -, +, +/-..

10-Good coding practices and clean code..

11-Should look like IOS calculator(image bellow).

Nice to have.

1-Should look like iOS calculator.

2-Front-end is fully responsive on all resolution sizes from iPhone 5 to 4K.

3-Use State manager (MobX) and Styled Components.

4-Use in a Mono repo.

5-Calculator layout easily changeable. Easy, means we wouldn't need to change much code to change the layout of calculator..

6-Custom webpack config's instead of using react-scripts boilerplate.