initializationOptions are not passed to rust-analyzer

[ta3pks]

• Did you upgrade to latest plugin version? :heavy_check_mark:
• Did you upgrade to/compile latest binary? Run shell command bin/languageclient --version to get its version number. languageclient 0.1.161
• (Neovim users only) Did you check output of :checkhealth LanguageClient? :heavy_check_mark:
• Did you check troubleshooting? :heavy_check_mark:

Describe the bug

Initialization options described in rust analyzer manual has no effect on the language client. I enabled procmacros but still i get proc macro errors I also cannot seem to disable those diagnostics for the same reason usage of the options are clearly documented so either LanguageClient-neovim uses non-standard way of defining things or simply this is not implemented

let g:LanguageClient_serverCommands = {
            \ 'rust': {
            \"name":"rust-analyzer",
            \ "command":['rust-analyzer'],
            \ "initializationOptions":{
            \"rust-analyzer.procMacro.enable": v:true,
            \"rust-analyzer.cargo.loadOutDirsFromCheck": v:true,
            \},
            \ },
            \ }

Environment

• neovim/vim version (nvim --version or vim --version): NVIM v0.4.4
• This plugin version (git rev-parse --short HEAD): next branch
• This plugin's binary version (bin/languageclient --version): languageclient 0.1.161
• Minimal vimrc content (A minimal vimrc is the smallest vimrc that could reproduce the issue. Refer to an example here): Not relevant
• Language server link and version: rust-analyzer 60c501f

To Reproduce

Steps to reproduce the behavior:

• add client config

  
  let g:LanguageClient_serverCommands = {
          \ 'rust': {
          \"name":"rust-analyzer",
          \ "command":['rust-analyzer'],
          \ "initializationOptions":{
          \"rust-analyzer.procMacro.enable": v:true,
          \"rust-analyzer.cargo.loadOutDirsFromCheck": v:true,
          \},
          \ },
          \ }

- open a rust file which uses some proc macro such as `Serialize` derive macro
- watch the errors despite the initOptions

## Current behavior

Described above and the title multiple times.

## Expected behavior

Init options to take effect

## Screenshots

![image](https://user-images.githubusercontent.com/9097437/104828790-0cdf0c80-587e-11eb-9b92-2d76452a878c.png)
![image](https://user-images.githubusercontent.com/9097437/104828807-21230980-587e-11eb-9c54-b905d7d2279c.png)

[ta3pks]

options are supposed to be specified as nested maps one key at a time I guess this has nothing to do with LanguageClient-neovim afterall

[martskins]

I think the issue you are/were having is that the rust-analyzer. prefix on your options should not be included in this config section. The idea behind that not being necessary was that it was already clear that the initialization options were for rust-analyzer (or whatever server you were configuring), but maybe that's not clear or correct enough and it's worth changing it to require the full option name.

Essentially, what you want to have there is something like this instead:

...
"initializationOptions": {
  "procMacro.enable": v:true,
  "cargo.loadOutDirsFromCheck": v:true,
},
...

[ta3pks]

@martskins that doesnt work either

"initializatinonOptions":{
  "procMacro":{
    "enable":v:true
  }
}

dos work however