This is my CHIP-8 emulator written in Typescript with ES6. I also wrote this emulator using the functional programming paradigm. All of the CPU has been coded using pure functions that do not mutate state. I have also tried to push all side effects to the edges of my program as much as possible. emulator.ts is the one area of the program where I was forced to use a stateful object.
This program also has only one dependency. It was originally written using React and Redux, but I removed these dependencies because they weren't providing any benefit at all.
I'm personally a fan of the functional programming paradigm because I believe when you compose your programs using pure functions, it makes code a lot easier to follow. It also helps reduce bugs.
I was a little concerned at first because a downside of not mutating state is slower performance. That would especially be a big deal in an emulator. I was surprised to learn that composing my emulator using pure functions didn't seem to have any noticeable effect on performance at all.
You will need to have node and npm setup first before you can run this program locally.
First run the following command to install all dependencies:
$ npm install
You can then run the following commands to run the project locally:
$ npm run build
$ npm run start
This project contains a test suite that tests all of the CPU opcodes and logic. You can run unit tests using the following command:
$ npm run test