luv VS plenary.nvim

To answer the OP's question, you could tackle luv and libuv ecosystem, as a way to connect Lua to real-world systems (files, sockets, servers...). That's one way to put Lua skills to use, there are other great answers in the thread. Another recommendation is to go through Programming in Lua book, especially the later chapters where you learn how Lua talks to the host application.

Unfortunately I doubt they are able to use netrw, it interfaces with user facing buffers too much. Telescope uses plenary which uses lua's luv implementation (bound to vim.loop). Fzf-lua uses an external binary called fzf

Lua is still actively used so there is a great number of libraries that came out in last 9 years. A decent example is the luv library that is packed with great functionality. On the whole I'm quite satisfied with the ecosystem, but it all depends on the domain.

You should be able to find plenty of examples of asynchronous code at https://github.com/luvit/luv and translate it.

The first thing I would recommend is read the official documentation. Both libuv and luvit (or more specifically luv)

I spent some time converting the luv documentation to make it available in :help and make the vim.loop module more discoverable. Thought plugin authors might be interested.

I'm assuming this one.

I'm sure I'm late to the party, but if anyone's curious, I found this article super helpful in learning how to implement actual non-hello world functionality, and the luv documentation has practically been my homepage for the past few days.

If you are really interested in doing this yourself with loop, you should take a look at either plenary.job or netman.shell (I made the latter) as both are very well documented.

The big reason I ask is that reaching out to an external python shell to run commands (disregard the fact that its python running) is going to be much slower than using the in built lua JIT interpreter. Additionally, plenary has a built in curl function so you don't have to "reinvent the wheel".

There is also test harness in nvim-lua/plenary.nvim with a slightly different design, but still usable of course.

I am simply using busted or more specifically vusted which is a wrapper around busted for Neovim. It should be quite straightforward to learn the basics, I would say you mostly need to know these functions: describe, it (these are used to structure your test cases) and assert.are_same (to check for table equality). Some people are also using plenary which is also based on busted.

It's based on nvim-lua-plugin-template, but uses Nix flakes to run plenary.nvim tests.

Plenary plugin for Nvim

I think you can use plenary.nvim to reload lua module.

Well I'll be fucked, I didn't know that existed. reload