load project error about vscode-reasonml

[gilbert]

My 2c: I just installed this package about four hours ago, and the intellisense was working great! However, after restarting vscode, it seems to have stopped working. I no longer get inline error messages or autocompletions. I also see the command 'reason.showMerlinFiles' not found error.

[Haroenv]

I had the same issue because I installed reason-cli etc. while inside the VS Code terminal. When I quit the editor and launched it from another terminal it worked 👍

[kristojorg]

Update: After installing reason-cli (which is working properly again now), it now seems to be resolved.

[richsilv]

In case it's helpful for anyone, I experienced the same problem and resolved it by deleting my local ./node_modules/.cache

@bobzhang this is strange. Does it just happen with a specific project (and is the project source available)? Does it always give that error? It might have something to do with the environment detection part of the ocaml server but I'm not sure.

[kristojorg]

I am seeing this as well in chenglou's reason-react-example. It seems to be always giving that error. I'm also seeing an error in vscode itself: command 'reason.showMerlinFiles' not found. Not sure what's going wrong, sorry I am not more help, just getting started on this stuff : /

Okay, thanks for letting me know. I'm working on a new release which I think may fix this issue.

[kristojorg]

I just installed reason and merlin through opam (because the reason-cli script is currently broken), and now I am not seeing either of these errors, but now I no longer see a Reason debug output option, and there is no autocomplete available:

I suspect the initial issue I was seeing was caused by not having installed the latest reason/merlin/etc.

[gilbert]

If it helps, the extensions seems to be perpetually loading:

@gilbert: you could try adding dependency-env to the project dependencies, installing it, and see if that helps. I thought I had this particular issue fixed but I'll take a look at it and see what's going on.

[kristojorg]

Could it be related to hackwaly/vscode-ocaml#78 ?

[gilbert]

@freebroccolo Do you mean https://www.npmjs.com/package/dependency-env ? If so, doesn't seem to help.

It seems I now have Merlin running in VS Code, but it's not picking up my .merlin file:

I had seen my .merlin file at some point, but I think I'm messing with my ocaml install too much. I don't have intellisense, probably due to this.

Do you think you could provide a list of executables that vscode-reasonml requires to work properly?

Do you think you could provide a list of executables that vscode-reasonml requires to work properly?

Normally this extension only requires ocamlmerlin in order to function. The issue with some reason projects is that they do not use opam to install dependencies so they cannot be discovered by Merlin in the same way that OCaml libraries are found.

Instead, the idea is to install OCaml/Reason dependencies for a library locally to node_modules. The problem here that there is not a completely reliable way to detect whether a given project is using dependencies via open or via node_modules. The situation is even more complicated when using an IDE because the environment variables may need to be set up to refer to some particular node_modules which the editor only knows about once the project gets loaded; they can't just be set globally ahead of time.

The way this extension handles the situation is to use some heuristics to try and detect if a project is using local dependencies under node_modules. This involves trying to call dependency-env which is supposed to set the environment variables so that when ocamlmerlin is executed everything just works.

My impression was that this was supposed to be the convention to use for Reason projects which is why I baked it into the editor. The other alternative was to require the user to launch the editor from the terminal through npm run but I do not like this approach because I think it impacts usability too much and frankly it should not be necessary.

In any case, it seems some projects are not using dependency-env. I haven't been paying too close attention to current practices since I haven't had the opportunity to use Reason much lately so maybe the situation has changed.

@jordwalke @chenglou is dependency-env no longer recommended for this?

Anyway, I'll take a look at the project and see if I can figure out what's wrong.

Okay, with reason-react-example I think there is either something wrong with the way the .merlin file is setup or maybe there is a communication problem with bucklescript ppx stuff. If you rename or delete .merlin then the interactive features start working but you will get syntax errors for bucklescript specific stuff at that point. But if you just use some standard Reason syntax it will work.

I'll have to investigate further to figure out what is causing this. @bobzhang any ideas?

Closed since I don't know what caused the original issue and would need more information.

[avsm]

I ran across this issue in OCaml. It manifests as the extension remaining as "loading" perpetually. I didn't have merlin installed, so I resolved it by opam install merlin and reloading the extension, and it works great!