refactor(language_server): improve file watching for different tools

Author: Sysix

crates/oxc_language_server/src/backend.rs

@@ -327,7 +327,7 @@ impl LanguageServer for Backend {
                 continue;
             };
 
-            let (diagnostics, watchers, formatter_activated) =
+            let (diagnostics, registrations, unregistrations, formatter_activated) =
                 worker.did_change_configuration(&option.options).await;
 
             if formatter_activated && self.capabilities.get().is_some_and(|c| c.dynamic_formatting)
@@ -344,23 +344,8 @@ impl LanguageServer for Backend {
                 }
             }
 
-            if let Some(watchers) = watchers
-                && self.capabilities.get().is_some_and(|capabilities| capabilities.dynamic_watchers)
-            {
-                // remove the old watcher
-                removing_registrations.push(Unregistration {
-                    id: format!("watcher-{}", worker.get_root_uri().as_str()),
-                    method: "workspace/didChangeWatchedFiles".to_string(),
-                });
-                // add the new watcher
-                adding_registrations.push(Registration {
-                    id: format!("watcher-{}", worker.get_root_uri().as_str()),
-                    method: "workspace/didChangeWatchedFiles".to_string(),
-                    register_options: Some(json!(DidChangeWatchedFilesRegistrationOptions {
-                        watchers
-                    })),
-                });
-            }
+            removing_registrations.extend(unregistrations);
+            adding_registrations.extend(registrations);
         }
 
         if !new_diagnostics.is_empty() {

crates/oxc_language_server/src/formatter/server_formatter.rs

@@ -9,7 +9,7 @@ use oxc_formatter::{
 use oxc_parser::{ParseOptions, Parser};
 use tower_lsp_server::{
     UriExt,
-    lsp_types::{Position, Range, TextEdit, Uri},
+    lsp_types::{Pattern, Position, Range, TextEdit, Uri},
 };
 
 use crate::formatter::options::FormatOptions as LSPFormatOptions;
@@ -103,6 +103,23 @@ impl ServerFormatter {
             }
         }
     }
+
+    #[expect(clippy::unused_self)]
+    pub fn get_watcher_patterns(&self, options: &LSPFormatOptions) -> Pattern {
+        options.config_path.as_ref().map_or(FORMAT_CONFIG_FILE, |v| v).to_owned()
+    }
+
+    pub fn get_changed_watch_patterns(
+        &self,
+        old_options: &LSPFormatOptions,
+        new_options: &LSPFormatOptions,
+    ) -> Option<Pattern> {
+        if old_options != new_options && new_options.experimental {
+            return Some(self.get_watcher_patterns(new_options));
+        }
+
+        None
+    }
 }
 
 /// Returns the minimal text edit (start, end, replacement) to transform `source_text` into `formatted_text`

crates/oxc_language_server/src/linter/server_linter.rs

@@ -1,13 +1,14 @@
 use std::path::{Path, PathBuf};
 use std::str::FromStr;
 use std::sync::Arc;
+use std::vec;
 
 use ignore::gitignore::Gitignore;
 use log::{debug, warn};
 use oxc_linter::{AllowWarnDeny, LintIgnoreMatcher};
 use rustc_hash::{FxBuildHasher, FxHashMap, FxHashSet};
 use tokio::sync::Mutex;
-use tower_lsp_server::lsp_types::Uri;
+use tower_lsp_server::lsp_types::{Pattern, Uri};
 
 use oxc_linter::{
     Config, ConfigStore, ConfigStoreBuilder, ExternalPluginStore, LintOptions, Oxlintrc,
@@ -376,6 +377,39 @@ impl ServerLinter {
             // TODO: only the TsgoLinter needs to be dropped or created
             || old_options.type_aware != new_options.type_aware
     }
+
+    pub fn get_watch_patterns(&self, options: &LSPLintOptions, root_path: &Path) -> Vec<Pattern> {
+        let mut watchers = vec![
+            options.config_path.as_ref().unwrap_or(&"**/.oxlintrc.json".to_string()).to_owned(),
+        ];
+
+        for path in &self.extended_paths {
+            // ignore .oxlintrc.json files when using nested configs
+            if path.ends_with(".oxlintrc.json") && options.use_nested_configs() {
+                continue;
+            }
+
+            let pattern = path.strip_prefix(root_path).unwrap_or(path);
+
+            watchers.push(normalize_path(pattern).to_string_lossy().to_string());
+        }
+        watchers
+    }
+
+    pub fn get_changed_watch_patterns(
+        &self,
+        old_options: &LSPLintOptions,
+        new_options: &LSPLintOptions,
+        root_path: &Path,
+    ) -> Option<Vec<Pattern>> {
+        if old_options.config_path == new_options.config_path
+            && old_options.use_nested_configs() == new_options.use_nested_configs()
+        {
+            return None;
+        }
+
+        Some(self.get_watch_patterns(new_options, root_path))
+    }
 }
 
 #[cfg(test)]