Advent2019

Attempt at solving Advent of code 2019 with an app using a Phoenix backend and a React frontend written in Typescript.

👌Comments are welcome, it's my first project using Phoenix and also Typescript :)

Screenshot

How to run

You need a recent Elixir and Node.js. Then run:

`make build-and-serve`

it will be visible at localhost:4000

To run in dev mode (that is, the frontend reloads on the fly), use yarn start in the assets folder (will expose the app at port 3000) and mix phx.server to run the backend at port 4000. The proxy option in the package.json will redirect requests to port 3000 to the actual backend.

Performance profiling

Use mix Exprof to profile the most critical parts of the backend.

Dialyze check

Use mix dialyze to statically check the types n the whole project

Current state

• day 1 ok!
• day 2 ok!
• day 3 ok!
• day 4 ok!
• day 5 ok!
• day 6 performance issue, the mix profile task profiles it. It is doing more than needed, the problem asks to count the paths and I'm enumerating them. The graph representation in the frontend doesn't scale with so many edges and is disabled.
• day 7 part 1 done, part 2 gives invalid results but don't know where the error is
• day 8 ok! The space image parsing was initially slow, now fixed
• 9 based on intcode computer, skipped for a better day
• 10 completed, visualization could be fun to add
• 12 done, a concurrent solution allows to explore the system periodicity in different axis quicker.
• 13 skipped for now because of IntCode computer
• day 14 skipped, needs some trick to optimize stoichiometry and reuse reagents
• day 15 skipped because intcode
• day 16 skipped for now as the problem definition is quite complex
• day 17 skipped because intcode
• day 18 is intriguing :) Implemented a solution for part 1 but it's megaslow. Drafted an improvement based on pruning. Also, weird Dialyze issues.
• day 19 skipped because intcode
• day 20

📓 development notes

These notes are here so I can remember how I built this in the future.

This app was created with:

mix phx.new advent2019 --no-ecto --no-webpack --no-html

Then in the folder I create the boilerplate react app: npx create-react-app assets --typescript

The normal build with yarn build can be then exposed by modifying plug Plug.Static in lib/advent2019_web/endpoint.ex.

TODO

• find a way to serve the app using yarn serve and its reload in development
• understand what exactly the only parameter of Plug.Static does and configure it properly
• tests, maybe try TDD?
• tests are executed only when the file is specified to mix test, why are they not mounted? (solution: because I wrote text, not test -_-)
• multiple days in same app
• error management in case of weird API call content
• make it responsive (it breaks on phone)
• improve a11y
• dockerize
• use proper logging for the BE
• code review based on experienced Elixir users and comparison with other people solutions, subsequent Anki deck creation (maybe a shared deck and a link to it?)

License

This is MIT licensed, please do pretty much whatever you want with it