draft(oxlnt/lsp): support jsPlugins

Author: Sysix

.vscode/settings.json

@@ -1,4 +1,5 @@
 {
+  "oxc.path.server": "./apps/oxlint/dist/cli.js",
   "oxc.typeAware": true,
   "oxc.configPath": "oxlintrc.json",
   "oxc.fmt.experimental": true,

apps/oxlint/src-js/plugins/load.ts

@@ -1,14 +1,14 @@
 import { pathToFileURL } from 'node:url';
 
-import { createContext } from './context.js';
 import { getErrorMessage } from '../utils/utils.js';
+import { createContext } from './context.js';
 
 import type { Writable } from 'type-fest';
+import type { SetNullable } from '../utils/types.ts';
 import type { Context } from './context.ts';
 import type { JsonValue } from './json.ts';
 import type { RuleMeta } from './rule_meta.ts';
 import type { AfterHook, BeforeHook, Visitor, VisitorWithHooks } from './types.ts';
-import type { SetNullable } from '../utils/types.ts';
 
 const ObjectKeys = Object.keys;
 
@@ -128,15 +128,18 @@ export async function loadPlugin(path: string, packageName: string | null): Prom
  * @param path - Absolute path of plugin file
  * @param packageName - Optional package name from `package.json` (fallback if `plugin.meta.name` is not defined)
  * @returns - Plugin details
- * @throws {Error} If plugin has already been registered
  * @throws {Error} If plugin has no name
  * @throws {TypeError} If one of plugin's rules is malformed, or its `createOnce` method returns invalid visitor
  * @throws {TypeError} if `plugin.meta.name` is not a string
  * @throws {*} If plugin throws an error during import
  */
 async function loadPluginImpl(path: string, packageName: string | null): Promise<PluginDetails> {
   if (DEBUG) {
-    if (registeredPluginPaths.has(path)) throw new Error('This plugin has already been registered');
+    /// if (registeredPluginPaths.has(path)) throw new Error('This plugin has already been registered');
+
+    // If plugin was already registered, unregister it first.
+    // This allows re-loading the plugin when the linter is restarted in `--lsp` mode.
+    registeredPluginPaths.delete(path);
     registeredPluginPaths.add(path);
   }
 

apps/oxlint/src/js_plugins/external_linter.rs

@@ -1,4 +1,4 @@
-use std::sync::{atomic::Ordering, mpsc::channel};
+use std::sync::{Arc, atomic::Ordering, mpsc::channel};
 
 use napi::{
     Status,
@@ -36,7 +36,7 @@ pub fn create_external_linter(
 ///
 /// The returned function will panic if called outside of a Tokio runtime.
 fn wrap_load_plugin(cb: JsLoadPluginCb) -> ExternalLinterLoadPluginCb {
-    Box::new(move |plugin_path, package_name| {
+    Arc::new(Box::new(move |plugin_path, package_name| {
         let cb = &cb;
         tokio::task::block_in_place(|| {
             tokio::runtime::Handle::current().block_on(async move {
@@ -49,7 +49,7 @@ fn wrap_load_plugin(cb: JsLoadPluginCb) -> ExternalLinterLoadPluginCb {
                 Ok(plugin_load_result)
             })
         })
-    })
+    }))
 }
 
 /// Result returned by `lintFile` JS callback.
@@ -69,7 +69,7 @@ pub enum LintFileReturnValue {
 /// Use an `mpsc::channel` to wait for the result from JS side, and block current thread until `lintFile`
 /// completes execution.
 fn wrap_lint_file(cb: JsLintFileCb) -> ExternalLinterLintFileCb {
-    Box::new(
+    Arc::new(Box::new(
         move |file_path: String,
               rule_ids: Vec<u32>,
               settings_json: String,
@@ -115,7 +115,7 @@ fn wrap_lint_file(cb: JsLintFileCb) -> ExternalLinterLintFileCb {
                 Err(err) => panic!("Callback did not respond: {err}"),
             }
         },
-    )
+    ))
 }
 
 /// Get buffer ID of the `Allocator` and, if it hasn't already been sent to JS,

apps/oxlint/src/lsp.rs

@@ -1,4 +1,7 @@
 /// Run the language server
-pub async fn run_lsp() {
-    oxc_language_server::run_server(vec![Box::new(oxc_language_server::ServerLinterBuilder)]).await;
+pub async fn run_lsp(external_linter: Option<oxc_linter::ExternalLinter>) {
+    oxc_language_server::run_server(vec![Box::new(oxc_language_server::ServerLinterBuilder::new(
+        external_linter,
+    ))])
+    .await;
 }

apps/oxlint/src/main.rs

@@ -9,7 +9,7 @@ async fn main() -> CliRunResult {
 
     // If --lsp flag is set, run the language server
     if command.lsp {
-        run_lsp().await;
+        run_lsp(None).await;
         return CliRunResult::LintSucceeded;
     }
 

apps/oxlint/src/run.rs

@@ -91,9 +91,18 @@ async fn lint_impl(
         }
     };
 
+    // JS plugins are only supported on 64-bit little-endian platforms at present
+    #[cfg(all(target_pointer_width = "64", target_endian = "little"))]
+    let external_linter = Some(super::js_plugins::create_external_linter(load_plugin, lint_file));
+    #[cfg(not(all(target_pointer_width = "64", target_endian = "little")))]
+    let external_linter = {
+        let (_, _) = (load_plugin, lint_file);
+        None
+    };
+
     // If --lsp flag is set, run the language server
     if command.lsp {
-        crate::lsp::run_lsp().await;
+        crate::lsp::run_lsp(external_linter).await;
         return CliRunResult::LintSucceeded;
     }
 
@@ -102,15 +111,6 @@ async fn lint_impl(
 
     command.handle_threads();
 
-    // JS plugins are only supported on 64-bit little-endian platforms at present
-    #[cfg(all(target_pointer_width = "64", target_endian = "little"))]
-    let external_linter = Some(super::js_plugins::create_external_linter(load_plugin, lint_file));
-    #[cfg(not(all(target_pointer_width = "64", target_endian = "little")))]
-    let external_linter = {
-        let (_, _) = (load_plugin, lint_file);
-        None
-    };
-
     // stdio is blocked by LineWriter, use a BufWriter to reduce syscalls.
     // See `https://github.com/rust-lang/rust/issues/60673`.
     let mut stdout = BufWriter::new(std::io::stdout());

crates/oxc_language_server/src/linter/isolated_lint_handler.rs

@@ -10,9 +10,9 @@ use tower_lsp_server::{UriExt, lsp_types::Uri};
 
 use oxc_allocator::Allocator;
 use oxc_linter::{
-    AllowWarnDeny, ConfigStore, DisableDirectives, Fix, FixKind, LINTABLE_EXTENSIONS, LintOptions,
-    LintRunner, LintRunnerBuilder, LintServiceOptions, Linter, Message, PossibleFixes,
-    RuleCommentType, RuntimeFileSystem, read_to_arena_str, read_to_string,
+    AllowWarnDeny, ConfigStore, DisableDirectives, ExternalLinter, Fix, FixKind,
+    LINTABLE_EXTENSIONS, LintOptions, LintRunner, LintRunnerBuilder, LintServiceOptions, Linter,
+    Message, PossibleFixes, RuleCommentType, RuntimeFileSystem, read_to_arena_str, read_to_string,
 };
 
 use super::error_with_position::{
@@ -67,11 +67,12 @@ impl IsolatedLintHandler {
     pub fn new(
         lint_options: LintOptions,
         config_store: ConfigStore,
+        external_linter: Option<ExternalLinter>,
         options: &IsolatedLintHandlerOptions,
     ) -> Self {
         let config_store_clone = config_store.clone();
 
-        let linter = Linter::new(lint_options, config_store, None);
+        let linter = Linter::new(lint_options, config_store, external_linter);
         let mut lint_service_options = LintServiceOptions::new(options.root_path.clone())
             .with_cross_module(options.use_cross_module);
 
@@ -121,6 +122,7 @@ impl IsolatedLintHandler {
         debug!("lint {}", path.display());
         let rope = &Rope::from_str(source_text);
 
+        // ToDO: with external linter, we need a new FS (raw) system
         let fs = IsolatedLintHandlerFileSystem::new(path.to_path_buf(), Arc::from(source_text));
 
         let mut messages: Vec<DiagnosticReport> = self