Call clearLoadedPlugin in ExternalLinter destructor

- Add JsClearLoadedPluginCb type to handle plugin state clearing
- Add clearLoadedPlugin callback parameter to create_external_linter
- Implement Drop trait for ExternalLinter to call clearLoadedPlugin
- Update lint and lint_impl to accept and pass clearLoadedPlugin callback
- Update cli.ts to pass clearLoadedPluginWrapper callback
- Export ExternalLinterClearLoadedPluginCb from oxc_linter

The clearLoadedPlugin function is now automatically called when the ExternalLinter is destroyed, ensuring plugin state is properly cleaned up after linting completes.

Co-authored-by: Sysix <[email protected]>

Author: Copilot

apps/oxlint/src-js/bindings.d.ts

@@ -1,5 +1,9 @@
 /* auto-generated by NAPI-RS */
 /* eslint-disable */
+/** JS callback to clear loaded plugins. */
+export type JsClearLoadedPluginCb =
+  (() => void)
+
 /** JS callback to lint a file. */
 export type JsLintFileCb =
   ((arg0: string, arg1: number, arg2: Uint8Array | undefined | null, arg3: Array<number>, arg4: string) => string)
@@ -15,7 +19,8 @@ export type JsLoadPluginCb =
  * 1. `args`: Command line arguments (process.argv.slice(2))
  * 2. `load_plugin`: Load a JS plugin from a file path.
  * 3. `lint_file`: Lint a file.
+ * 4. `clear_loaded_plugin`: Clear loaded plugin state.
  *
  * Returns `true` if linting succeeded without errors, `false` otherwise.
  */
-export declare function lint(args: Array<string>, loadPlugin: JsLoadPluginCb, lintFile: JsLintFileCb): Promise<boolean>
+export declare function lint(args: Array<string>, loadPlugin: JsLoadPluginCb, lintFile: JsLintFileCb, clearLoadedPlugin: JsClearLoadedPluginCb): Promise<boolean>

apps/oxlint/src-js/cli.ts

@@ -6,6 +6,7 @@ import { debugAssertIsNonNull } from './utils/asserts.js';
 // are identical. Ditto `lintFile` and `lintFileWrapper`.
 let loadPlugin: typeof loadPluginWrapper | null = null;
 let lintFile: typeof lintFileWrapper | null = null;
+let clearLoadedPlugin: typeof clearLoadedPluginWrapper | null = null;
 
 /**
  * Load a plugin.
@@ -21,7 +22,7 @@ function loadPluginWrapper(path: string, packageName: string | null): Promise<st
     // Use promises here instead of making `loadPluginWrapper` an async function,
     // to avoid a micro-tick and extra wrapper `Promise` in all later calls to `loadPluginWrapper`
     return import('./plugins/index.js').then((mod) => {
-      ({ loadPlugin, lintFile } = mod);
+      ({ loadPlugin, lintFile, clearLoadedPlugin } = mod);
       return loadPlugin(path, packageName);
     });
   }
@@ -54,11 +55,23 @@ function lintFileWrapper(
   return lintFile(filePath, bufferId, buffer, ruleIds, settingsJSON);
 }
 
+/**
+ * Clear loaded plugin state.
+ *
+ * Delegates to `clearLoadedPlugin`, which was lazy-loaded by `loadPluginWrapper`.
+ * If plugins haven't been loaded yet, this is a no-op.
+ */
+function clearLoadedPluginWrapper(): void {
+  if (clearLoadedPlugin !== null) {
+    clearLoadedPlugin();
+  }
+}
+
 // Get command line arguments, skipping first 2 (node binary and script path)
 const args = process.argv.slice(2);
 
-// Call Rust, passing `loadPlugin` and `lintFile` as callbacks, and CLI arguments
-const success = await lint(args, loadPluginWrapper, lintFileWrapper);
+// Call Rust, passing `loadPlugin`, `lintFile`, and `clearLoadedPlugin` as callbacks, and CLI arguments
+const success = await lint(args, loadPluginWrapper, lintFileWrapper, clearLoadedPluginWrapper);
 
 // Note: It's recommended to set `process.exitCode` instead of calling `process.exit()`.
 // `process.exit()` kills the process immediately and `stdout` may not be flushed before process dies.

apps/oxlint/src/js_plugins/external_linter.rs

@@ -15,18 +15,20 @@ use oxc_linter::{
 
 use crate::{
     generated::raw_transfer_constants::{BLOCK_ALIGN, BUFFER_SIZE},
-    run::{JsLintFileCb, JsLoadPluginCb},
+    run::{JsClearLoadedPluginCb, JsLintFileCb, JsLoadPluginCb},
 };
 
 /// Wrap JS callbacks as normal Rust functions, and create [`ExternalLinter`].
 pub fn create_external_linter(
     load_plugin: JsLoadPluginCb,
     lint_file: JsLintFileCb,
+    clear_loaded_plugin: JsClearLoadedPluginCb,
 ) -> ExternalLinter {
     let rust_load_plugin = wrap_load_plugin(load_plugin);
     let rust_lint_file = wrap_lint_file(lint_file);
+    let rust_clear_loaded_plugin = wrap_clear_loaded_plugin(clear_loaded_plugin);
 
-    ExternalLinter::new(rust_load_plugin, rust_lint_file)
+    ExternalLinter::new(rust_load_plugin, rust_lint_file, rust_clear_loaded_plugin)
 }
 
 /// Wrap `loadPlugin` JS callback as a normal Rust function.
@@ -59,6 +61,16 @@ pub enum LintFileReturnValue {
     Failure(String),
 }
 
+/// Wrap `clearLoadedPlugin` JS callback as a normal Rust function.
+///
+/// This function is called when the `ExternalLinter` is dropped to clear loaded plugin state.
+fn wrap_clear_loaded_plugin(cb: JsClearLoadedPluginCb) -> oxc_linter::ExternalLinterClearLoadedPluginCb {
+    Box::new(move || {
+        // Call the JavaScript callback to clear loaded plugin state
+        let _ = cb.call((), ThreadsafeFunctionCallMode::Blocking);
+    })
+}
+
 /// Wrap `lintFile` JS callback as a normal Rust function.
 ///
 /// The returned function creates a `Uint8Array` referencing the memory of the given `Allocator`,

apps/oxlint/src/run.rs

@@ -52,28 +52,43 @@ pub type JsLintFileCb = ThreadsafeFunction<
     false,
 >;
 
-
+/// JS callback to clear loaded plugins.
+#[napi]
+pub type JsClearLoadedPluginCb = ThreadsafeFunction<
+    // Arguments
+    (),
+    // Return value
+    (),
+    // Arguments (repeated)
+    (),
+    // Error status
+    Status,
+    // CalleeHandled
+    false,
+>;
 
 /// NAPI entry point.
 ///
 /// JS side passes in:
 /// 1. `args`: Command line arguments (process.argv.slice(2))
 /// 2. `load_plugin`: Load a JS plugin from a file path.
 /// 3. `lint_file`: Lint a file.
+/// 4. `clear_loaded_plugin`: Clear loaded plugin state.
 ///
 /// Returns `true` if linting succeeded without errors, `false` otherwise.
 #[expect(clippy::allow_attributes)]
 #[allow(clippy::trailing_empty_array, clippy::unused_async)] // https://github.com/napi-rs/napi-rs/issues/2758
 #[napi]
-pub async fn lint(args: Vec<String>, load_plugin: JsLoadPluginCb, lint_file: JsLintFileCb) -> bool {
-    lint_impl(args, load_plugin, lint_file).await.report() == ExitCode::SUCCESS
+pub async fn lint(args: Vec<String>, load_plugin: JsLoadPluginCb, lint_file: JsLintFileCb, clear_loaded_plugin: JsClearLoadedPluginCb) -> bool {
+    lint_impl(args, load_plugin, lint_file, clear_loaded_plugin).await.report() == ExitCode::SUCCESS
 }
 
 /// Run the linter.
 async fn lint_impl(
     args: Vec<String>,
     load_plugin: JsLoadPluginCb,
     lint_file: JsLintFileCb,
+    clear_loaded_plugin: JsClearLoadedPluginCb,
 ) -> CliRunResult {
     // Convert String args to OsString for compatibility with bpaf
     let args: Vec<std::ffi::OsString> = args.into_iter().map(std::ffi::OsString::from).collect();
@@ -106,10 +121,10 @@ 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));
+    let external_linter = Some(super::js_plugins::create_external_linter(load_plugin, lint_file, clear_loaded_plugin));
     #[cfg(not(all(target_pointer_width = "64", target_endian = "little")))]
     let external_linter = {
-        let (_, _) = (load_plugin, lint_file);
+        let (_, _, _) = (load_plugin, lint_file, clear_loaded_plugin);
         None
     };
 

crates/oxc_linter/src/external_linter.rs

@@ -16,6 +16,8 @@ pub type ExternalLinterLintFileCb = Box<
         + Send,
 >;
 
+pub type ExternalLinterClearLoadedPluginCb = Box<dyn Fn() + Send + Sync>;
+
 #[derive(Clone, Debug, Deserialize)]
 pub enum PluginLoadResult {
     #[serde(rename_all = "camelCase")]
@@ -47,14 +49,23 @@ pub struct JsFix {
 pub struct ExternalLinter {
     pub(crate) load_plugin: ExternalLinterLoadPluginCb,
     pub(crate) lint_file: ExternalLinterLintFileCb,
+    clear_loaded_plugin: ExternalLinterClearLoadedPluginCb,
 }
 
 impl ExternalLinter {
     pub fn new(
         load_plugin: ExternalLinterLoadPluginCb,
         lint_file: ExternalLinterLintFileCb,
+        clear_loaded_plugin: ExternalLinterClearLoadedPluginCb,
     ) -> Self {
-        Self { load_plugin, lint_file }
+        Self { load_plugin, lint_file, clear_loaded_plugin }
+    }
+}
+
+impl Drop for ExternalLinter {
+    fn drop(&mut self) {
+        // Clear loaded plugin state when the linter is destroyed
+        (self.clear_loaded_plugin)();
     }
 }
 

crates/oxc_linter/src/lib.rs

@@ -60,8 +60,8 @@ pub use crate::{
     },
     context::{ContextSubHost, LintContext},
     external_linter::{
-        ExternalLinter, ExternalLinterLintFileCb, ExternalLinterLoadPluginCb, JsFix,
-        LintFileResult, PluginLoadResult,
+        ExternalLinter, ExternalLinterClearLoadedPluginCb, ExternalLinterLintFileCb,
+        ExternalLinterLoadPluginCb, JsFix, LintFileResult, PluginLoadResult,
     },
     external_plugin_store::{ExternalPluginStore, ExternalRuleId},
     fixer::{Fix, FixKind, Message, PossibleFixes},