This project is built with Nest framework.
To create thumbnails i've used npm package video-thumbnail-generator which requires ffmpeg to be installed.
For MacOS it was enough to:
brew install ffmpeg
There is also a way to get by without thumbnails.
Once it is ready - init things in common npm project way:
npm install
npm start
$ npm run test
Tests are not numerous.
There are some default dummy NestJS tests (which are created by CLI when you create services/controllers), but i've generalized them with some helper to avoid repetition.
Also i've created a stupid unit test src/video/video.service.spec.ts just to show that i've got overall idea of what Jest is about.
If for some reason it is a problem to have ffmpeg installed you can get by patching src/config.ts config file setting createThumbnails param to false. The UI would look lame, there would be 404s for missing thumbnails but overall things would work and you should be fine to play videos.
I did cheat a little bit. Occasionally i've come across the repo: https://github.com/jamesb3ll/mytube-react-graphql and found out there's a way to hanlde file upload staying within graphQL API
Trying to do something similar i stuck with the fact that currently 'graphql-tools' i am using is not capable of mapping all things for that upload and i gave up for now https://www.apollographql.com/docs/apollo-server/data/file-uploads/ ardatan/graphql-tools#671
That is why i just upload files with REST multipart/form-data request.
Leftovers of what i tried are in wrong-way-gql-upload but again i don't think it is worth seeing.
That thumbnail creating lib introduced severe security issues into the project. Since this one is a sample i did not bother solving this problem. In real life if that vulnerability is serious (which may come out of nature of that ffmpeg external lib or something) that might be solved by separating thumbnail creation from the server itself, into the lambda or othem microservice, for instance. I mean other thumbnail packages still depend on that lib and might share the same vulnerabilities.
I even forgot i was going to replace inmemory array of videos with some database (initially i was going to use mongo but eventually i just left it as is), got that used to this state of things that even forgot to mention.