Add support for .node-version files

[Dean177]

I attempted to add support for .node-version files.

I'm brand new to the reason ecosystem so have absolutely no idea what I am doing.

The files in the esy.lock directory seem to have changed quite substantially, have I done something wrong to cause this?

Resolves #8

[Schniz]

This is very very very good! Thanks!
Take a look at what I've commented - what do you think?

[Schniz]

What if versionString would catch the errors and provide option(string), that means that Some("file contents") or None when file not found?
then, this code would be easier to follow and Reason's amazing pattern matching will help us:

let%lwt nodeVersion = Filename.concat(cwd, ".node-version") |> versionString
and nvmrc = Filename.concat(cwd, ".nvmrc") |> versionString;

switch (nodeVersion, nvmrc) {
| (None, None) => Lwt.fail(Version_Not_Provided)
| (Some(_), Some(_)) => Lwt.failwith("You have both .node-version and .nvmrc!")
| (Some(version), None)
| (None, Some(version)) => Lwt.return(version)
};

[Schniz]

or even:

let%lwt nodeVersion = Filename.concat(cwd, ".node-version") |> versionString
and nvmrc = Filename.concat(cwd, ".nvmrc") |> versionString;

switch (nodeVersion, nvmrc) {
| (None, None) => Lwt.fail(Version_Not_Provided)
| (Some(version), Some(_))
| (Some(version), None)
| (None, Some(version)) => Lwt.return(version)
};

[Dean177]

Good idea and thanks for the feedback. I think in the case where a user has both a .node-version and an .nvmrc we can be permissive if they contain matching versions (since they might just want to support multiple clients).

Whats the difference between:

let%lwt nodeVersion = Filename.concat(cwd, ".node-version") |> versionString
and nvmrc = Filename.concat(cwd, ".nvmrc") |> versionString;

and

let%lwt nodeVersion = Filename.concat(cwd, ".node-version") |> versionString;
let%lwt nvmrc = Filename.concat(cwd, ".nvmrc") |> versionString;

The docs mention parallel binding: https://ocsigen.org/lwt/3.2.1/api/Ppx_lwt
Does this mean they will actually be run in parallel?

[Schniz]

Indeed, it’s like Promise.all!

[Schniz]

👏

[Schniz]

I'm brand new to the reason ecosystem so have absolutely no idea what I am doing.

May I just add, that it sure doesn't look this way.
Looks very very good 😄

[Schniz]

Looks much much cleaner! 🤩
What do you think about taking the conditional into the pattern matching clause?

[Schniz]

This can even be reduced further using:

  | (Some(v1), Some(v2) when v1 == v2 =>

Then, no nesting in our pattern matching! Wdyt?

[Schniz]

Or even better; check if it isn’t equal first :)

[Schniz]

Amazing 🏆 💯 🌮

Thanks!