setup: add nix flake

[Yohh]

Description

nix package manager users can setup a shell environnement based on a flake.nix file that describes tools and versions needed to dev and run the project, this flake contains:

• nodejs 20
• npm
• typescript language server
• angular language service

nix flakes combinated with direnv allow to open a project folder with automatic setup launch, creates en .envrc file and a .direnv directory. -> not every contributors use it and want to have those dotfiles, so it should be ignored by git.

Issues

Checklist

• This PR contains a description of the changes I'm making
• I've read the Contribution Guidelines
• I've added tests for changes or features I've introduced
• I documented any high-level concepts I'm introducing in documentation/
• CI is currently green and this is ready for review

[aiAdrian]

@louisgreiner I don't understand the changes. Does this change have any impact on the current application with respect to local installation, integration, etc., or does it only enable a new way to work with the Netzgrafik-Editor in terms of developing tools?

[Yohh]

@louisgreiner I don't understand the changes. Does this change have any impact on the current application with respect to local installation, integration, etc., or does it only enable a new way to work with the Netzgrafik-Editor in terms of developing tools?

it has no impact on anyone who doesn't use nix package manager, but it allows nix users to setup quickly and sustainably the tools to work on NGE, at the good version, with no need to manually switch between tool versions from a project to another.

a lot of OSRD developpers use nix, that's why I propose this addition

[louisgreiner]

As @Yohh mentionned, Nix won't impact the current state of NGE (as for the development, the integration or the usability of the application). It only provides a new way to very quickly setup the project for developers.

For instance, NGE uses a specific version of NPM (and other packages), however, another project can use different versions for these packages : it can be boring for the developer to switch from a version to another all day.

When projects get bigger, it become especially important to have these tools, to support the developers' setups. (I also, i.e., use Nix for OSRD)

In conclusion: it won't impact NGE, nor the use we have from a developer point of view, but neither the stability of the application

[louisgreiner]

Would it be possible to write some documentation on how to use the flake ? Or at least a link to redirect to Nix setup ?

Otherwise nice feature, I'm gonna test it soon

[Yohh]

Would it be possible to write some documentation on how to use the flake ? Or at least a link to redirect to Nix setup ?

Otherwise nice feature, I'm gonna test it soon

done for documentation

my linter has cleaned some extra-lines, tell me if you want me to erase those changes

[louisgreiner]

Tested, it works very well 🎉 We can hope it will allow more people to contribute to NGE