Yieldify Interview Question

Solution to the Yieldify Developer Interview challenge. Tasked to build a simple bouncy ball physics game in Typescript

Solution Notes

• System split into classes and each class is self contained and handles its own physics
• Applies basic physics laws such as the forces of friction and elasticity
• Allows live editing of configuration values such as gravity and coefficient of friction
• Assumes mass of all balls is 1 unit
• Game tick is run on requestAnimationFrame but doesn't take into account time since last tick so it will run faster on some machines and slower on others

Full Task

Overview and Test Instructions:

• Use any combination of web technologies to complete the task.
• All code should be authored by the applicant: do not use game engines, physics engines or 3rd party libraries.
• Submit in a format that is easy for us to run / inspect from the browser.
• Your code should be written as if it were going to be deployed today ­ i.e. using standard technologies commonly supported by most current browsers.
• You will be evaluated both on your implementation choices and the quality of your code; so please ensure code is well­structured, extensible, testable, readable, commented etc.
• Any 3rd party code (at all) should be clearly attributed

Challenge

• Stage 1 Whenever the user clicks on the page, a circle is 'fired' from the clicked position at a random speed and angle. [Please ensure that your solution handles multiple balls being fired and bounching at the same time].
• Stage 2 When the projectile reaches the bottom of the browser window it should bounce until it stops
• Stage 3 Submit
• Bonus Tests and tooling for minification and automation of the workflow

Repository Info

Repo Structure

• src - Main source code folder containing all .ts files
• test - Root folder for all tests
• resources - Folder for all static resources
  • public - Contains the html to render the page and also systemjs
  • styles - Uncompiled scss styles
• build - Compiled js and css

Development Info

Requirements

• NodeJS (v6.X.X)

Running the code

1. Clone the Repo onto your local machine
2. Install the npm dependancies: npm i
3. Build the code (and startup browserify): npm run clusterbomb (VSCode: Cmd+Shift+B)

Running the tests

1. Clone the Repo onto your local machine
2. Install the npm dependancies: npm i
3. Build and run the tests: npm test