feat(language_server/vscode): support multi workspace folder setups

[Sysix]

Server Side Changes

As a Server, we need to make sure we follow the LSP specifications. So can not make changes in VSCode and implement them in the language server.

initialize

Check if a custom configuration is passed with initialization_options. Not every Client will send a configuration and expect that the server will request them with workspace/configuration.

We still uses root_uri as a fallback for older clients which do not support workspace folders.

Every use case tries to have a good fallback when something is wrong.

Change Configuration

The Client is sending a Custom Configuration to the Client. Not every Client will send it. So we request for the specific workspace configuration and update them.

Workspace Folder Change

This is new and should be self explained.

Client (VSCode Side Changes)

Changed Configuration scopes

This should reflect what the server will support.

onConfigChange

We are now making sure that we check for every possible configuration. Custom User Configuration we will ignore.

Testing

Testing will be done with #10648.
We need to change the test structure to different between multi root setups and normal setups.
Not every test should be executed twice.

I tried to test every use case with VSCode possible and only found one problem.
When we add a workspace folder with an already defined oxc.configPath, we want to restart the server, but the onConfigChange event will already fire workspace/didChangeConfiguration request. This will result into a small error window, but still works perfectly.
We should avoid restarting the server when we need to create new file watchers. There are some workarounds that the server needs to support first. This is a task for later :)

[Sysix]

• test(editor): add tests for multi workspace folder setup #10648
• feat(language_server/vscode): support multi workspace folder setups #10515 👈 (View in Graphite)
• refactor(editor): split Config to VSCodeConfig and WorkspaceConfig #10572
• refactor(language_server): make linter independent of Backend #10497
• refactor(language_server): do not request for worspace configuration when the client does not support it #10507
• refactor(language_server): move code actions into own file #10479
• main

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[codspeed-hq]

CodSpeed Instrumentation Performance Report

Merging #10515 will not alter performance

_{Comparing 04-20-feat_language_server_support_multiple_workspaces (01cc2e4) with main (315143a)}

Summary

✅ 36 untouched benchmarks

[Sysix]

Thanks for testing it out.
There is a problem with nested configuration, which is already in the main branch.
Created one test which passes for some reason, but fails in real world. Will look into it :)

EDIT: it is fixed in main and this PR is restacked

[nrayburn-tech]

Re-tested within IntelliJ today and didn't notice any issues. Both nested config and specific config path support seems to be working. I don't think I'll be able to review the actual code changes here, but general usage seemed fine for me.

I did find that IntelliJ does have some support for the workspace concept, but I'm not sure if that means it supports LSP workspaces. https://blog.jetbrains.com/idea/2024/08/workspaces-in-intellij-idea/
In either case, I didn't do any workspace testing.

[Boshen]

@camc314 can you merge after testing this PR manually?

[camc314]

@Sysix , mind clarifying how this is meant to work? I think i'm just doing something wront while testing though.

I tested on https://github.com/oxc-project/oxc-intellij-plugin/tree/main/sandbox, added a sandbox.code-workspace, opened the folder as a workspace, however On the left hand side, I've got no-debugger: allow, however the warning is still there? likewise, the warning for curly is missing on the left.

This is my sandbox.code-workspace file

{
    "folders": [
      {
        "path": "custom-config"
      },
      {
        "path": "nested-configs"
      }
    ]
  }

[Sysix]

@Sysix , mind clarifying how this is meant to work? I think i'm just doing something wront while testing though.

I tested my changes with the following changes:

In C:\Users\sysix\.....\settings.json I use the debug server with extra information.
So I am sure I always use the debug language server for every editor instance.

{
  "oxc.path.server": "/home/sysix/dev/oxc/editors/vscode/target/debug/oxc_language_server",
  "oxc.trace.server": "verbose"
}

I am also updating the docs to clarify how to use the debug version: oxc-project/website#357

Then add / remove folders to the workspace with the explorer:

Add another Git Repo:

When you're in single folder mode and adding a folder, VSCode will restart the window on my side.
The real testing can only be done with 2 or more folders.

Every workspace folder can be configured by its own Options:

[camc314]

Suggested change

	let Ok(configs) = self.client.configuration(config_items).await else {
	debug!("failed to get configuration");
	// return none for each workspace folder
	return vec![None; length];
	};
	let configs = match self.client.configuration(config_items).await {
	Ok(config) => config,
	Err(e) => {
	debug!("failed to get configuration {e:?}");
	return vec![None; length];
	}
	};

i think it would be ideal that the error is logged here?

[camc314]

thanks - been debugging this trying to work out whats going on, I keep on seeing the following, when running this (i changed the code slightly to add more logging, but the lsp gets the workspace folders, but fails to get configuration - error server not initiaizlized

2025-05-01 17:53:18.005 [info] [2025-05-01T16:53:18Z INFO  oxc_language_server] initialize Some(Object {"settings": Object {"run": String("onType"), "configPath": String("./custom-oxlint.jsonc"), "flags": Object {}}})

2025-05-01 17:53:18.005 [info] [2025-05-01T16:53:18Z INFO  oxc_language_server] initialize: Options { run: OnType, config_path: Some("./custom-oxlint.jsonc"), flags: {} }
[2025-05-01T16:53:18Z INFO  oxc_language_server] language server version: "0.16.8"

2025-05-01 17:53:18.005 [info] [2025-05-01T16:53:18Z INFO  oxc_language_server] workspace folders: Some([WorkspaceFolder { uri: Uri(Uri { scheme: Some("file"), authority: Some(Authority { userinfo: None, host: Host { text: "", data: RegName("") }, port: None }), path: "/Users/cameron/github/tmp/oxc-intellij-plugin/sandbox/custom-config", query: None, fragment: None }), name: "custom-config" }, WorkspaceFolder { uri: Uri(Uri { scheme: Some("file"), authority: Some(Authority { userinfo: None, host: Host { text: "", data: RegName("") }, port: None }), path: "/Users/cameron/github/tmp/oxc-intellij-plugin/sandbox/nested-configs", query: None, fragment: None }), name: "nested-configs" }, WorkspaceFolder { uri: Uri(Uri { scheme: Some("file"), authority: Some(Authority { userinfo: None, host: Host { text: "", data: RegName("") }, port: None }), path: "/Users/cameron/github/tmp/nodejs-loaders", query: None, fragment: None }), name: "nodejs-loaders" }])
[2025-05-01T16:53:18Z INFO  oxc_language_server] capabilities.workspace_configuration: true

2025-05-01 17:53:18.005 [info] [2025-05-01T16:53:18Z INFO  oxc_language_server] failed to get configuration Error { code: ServerError(-32002), message: "Server not initialized", data: None }
[2025-05-01T16:53:18Z INFO  oxc_language_server] configs [None, None, None]

2025-05-01 17:53:18.040 [info] [2025-05-01T16:53:18Z INFO  oxc_language_server] workers [Some(Uri(Uri { scheme: Some("file"), authority: Some(Authority { userinfo: None, host: Host { text: "", data: RegName("") }, port: None }), path: "/Users/cameron/github/tmp/oxc-intellij-plugin/sandbox/custom-config", query: None, fragment: None }))Mutex { data: Options { run: OnType, config_path: None, flags: {} } }, Some(Uri(Uri { scheme: Some("file"), authority: Some(Authority { userinfo: None, host: Host { text: "", data: RegName("") }, port: None }), path: "/Users/cameron/github/tmp/oxc-intellij-plugin/sandbox/nested-configs", query: None, fragment: None }))Mutex { data: Options { run: OnType, config_path: None, flags: {} } }, Some(Uri(Uri { scheme: Some("file"), authority: Some(Authority { userinfo: None, host: Host { text: "", data: RegName("") }, port: None }), path: "/Users/cameron/github/tmp/nodejs-loaders", query: None, fragment: None }))Mutex { data: Options { run: OnType, config_path: None, flags: {} } }]

The error comes from tower_lsp_server, so it never actually goes to vscode. do we need to do this init logic after the server is initiialzied.

tower code:

    /// Sends a custom request to the client.
    ///
    /// # Initialization
    ///
    /// If the request is sent to the client before the server has been initialized, this will
    /// immediately return `Err` with JSON-RPC error code `-32002` ([read more]).
    ///
    /// [read more]: https://microsoft.github.io/language-server-protocol/specification#initialize
    pub async fn send_request<R>(&self, params: R::Params) -> jsonrpc::Result<R::Result>
    where
        R: lsp_types::request::Request,
    {
        if let State::Initialized | State::ShutDown = self.inner.state.get() {
            self.send_request_unchecked::<R>(params).await
        } else {
            let id = i64::from(self.inner.request_id.load(Ordering::SeqCst)) + 1;
            let msg = Request::from_request::<R>(id.into(), params);
            trace!("server not initialized, supressing message: {}", msg);
            Err(jsonrpc::not_initialized_error())
        }
    }

[Sysix]

Thanks for this info ❤️

I looked into the initialized request and hope to fix it with it. But I got some new problems on the way.
The workspace folders are only passed in the initialize request. We can pass a new object to initialization_options, which will include all configuration and will resolve the problem, but it is not expected from the clients (VSCode, Vim, JetBrains, ...). We need to make sure we get the right configuration fix_kind / nested_configs before creating the ServerLinter.

My Plan:
Check for the server's custom initialization_options configuration. If they passed a valid initialization_options, we will create the ServerLinter on initialize.
If the ServerLinter is not created, and we are in initialized request. Request the possible workspace configurations and create the ServerLinter. Use the fallback if not supported.

I guess we need to move WorkspaceWorker.options and WorkspaceWorker.nested_configs to WorkspaceWorker.server_linter. On the way, we can refactor the keys from oxc.flags to oxc.lint.flags. (Formatter flags in mind)

The configuration WorkspaceWorker.gitignore_glob will be interesting because with the inclusion of the
formatter it will change and should not include .eslintignore file.

This was mostly notes for me to get my problems / ideas structured. @camc314 and every other feel free to give some feedback.

Will start tomorrow and some new PRs to get the goal ❤️
If you guys want, you can close the 2 PRs and I will rebuild them. The changes will require some time.

[camc314]

that sounds great, thank you for working on this! The code for this change looked good to me, just the issue with the client request during startup.

It's up to you if you would like to close this PR/create a new one