[WIP]: Sheldon diagnostics

[vkatsuba]

No description provided.

[robertoaloi]

Looks good, I left a couple of final comments. After that, we should be good to go.

[robertoaloi]

Hi @vkatsuba ! I gave this a try, but after enabling the sheldon diagnostics backend via the erlang_ls.config file I see some crashes:

1. The sheldon functions are undef. I suspect the app is not included in the escript correctly (it probably misses in the .app.src dependency chain.
2. The sheldon/priv/lang folder required by the backend also doesn't seem to be available, so even after patching 1, the sheldon_sup crashes.

Also, it looks like sheldon comes with a 5MB english dictionary. Including it would make Erlang LS more than double its size.
I wonder if, instead, we shouldn't provide the user the ability to point to a custom dictionary via the config file.
Finally, I suspect we will have to move the ast part from the rebar plugin to sheldon itself. The fact is that, by adding rebar3_sheldon as a dependency in the .app.src causes some rebar3 logic to trigger. In our internal project (1.5 million lines of code) this seems to trigger compilation for the whole project, which we cannot afford.

[vkatsuba]

Hi @robertoaloi!

The sheldon functions are undef.

Maybe the logic of init function or approach is wrong. Because we load sheldon in init behavior. Could you try do it the same with ref 652bc5830d640309aacfa44a723f7043956c1e02? I suppose this commit should be works.

The sheldon functions are undef. I suspect the app is not included in the escript correctly (it probably misses in the .app.src dependency chain.

We cannot add sheldon to .app.src because sheldon will try run and load and store dictionary by default. While it is expected that Sheldon can only start at a certain moment. Most likely you need to extend the plugin and add an API to run Sheldon separately.

The sheldon/priv/lang folder required by the backend also doesn't seem to be available, so even after patching 1, the sheldon_sup crashes.

This folder is a part of sheldon

Finally, I suspect we will have to move the ast part from the rebar plugin to sheldon itself.

If we do it, it will be no make sense to integrate rebar3_sheldon.

this seems to trigger compilation for the whole project, which we cannot afford.

The rebar3_sheldon works mostly the same as rebar3_format which is also added as a dependency to the current project. I changed the API on purpose of rebar3_sheldon for current integration for call functions for analysis of AST.

[robertoaloi]

So @vkatsuba if this doesn't work out of the box, how are you managing to get the diagnostics yourself?

[vkatsuba]

@robertoaloi I was focused on common tests only and didn't try it in some IDE.