fix: prevent file watcher issue (#2859)

* fix: prevent file watcher issue

* perf: check if file content changed in tsconfig file watch

Author: jasonlyu123

.changeset/green-adults-hammer.md

@@ -0,0 +1,5 @@
+---
+'svelte-check': patch
+---
+
+fix: prevent file watcher issue

.changeset/thirty-seas-post.md

@@ -0,0 +1,6 @@
+---
+'svelte-language-server': patch
+'svelte-check': patch
+---
+
+perf: check if file content changed in tsconfig file watch

packages/language-server/src/plugins/typescript/service.ts

@@ -965,7 +965,11 @@ async function createLanguageService(
     ) {
         if (
             kind === ts.FileWatcherEventKind.Changed &&
-            !configFileModified(fileName, modifiedTime ?? tsSystem.getModifiedTime?.(fileName))
+            !configFileModified(
+                fileName,
+                modifiedTime ?? tsSystem.getModifiedTime?.(fileName),
+                docContext
+            )
         ) {
             return;
         }
@@ -1328,7 +1332,8 @@ function createWatchDependedConfigCallback(docContext: LanguageServiceDocumentCo
             kind === ts.FileWatcherEventKind.Changed &&
             !configFileModified(
                 fileName,
-                modifiedTime ?? docContext.tsSystem.getModifiedTime?.(fileName)
+                modifiedTime ?? docContext.tsSystem.getModifiedTime?.(fileName),
+                docContext
             )
         ) {
             return;
@@ -1360,7 +1365,11 @@ function createWatchDependedConfigCallback(docContext: LanguageServiceDocumentCo
 /**
  * check if file content is modified instead of attributes changed
  */
-function configFileModified(fileName: string, modifiedTime: Date | undefined) {
+function configFileModified(
+    fileName: string,
+    modifiedTime: Date | undefined,
+    docContext: LanguageServiceDocumentContext
+) {
     const previousModifiedTime = configFileModifiedTime.get(fileName);
     if (!modifiedTime || !previousModifiedTime) {
         return true;
@@ -1371,6 +1380,20 @@ function configFileModified(fileName: string, modifiedTime: Date | undefined) {
     }
 
     configFileModifiedTime.set(fileName, modifiedTime);
+
+    const oldSourceFile =
+        parsedTsConfigInfo.get(fileName)?.parsedCommandLine?.options.configFile ??
+        docContext.extendedConfigCache.get(fileName)?.extendedResult;
+
+    if (
+        oldSourceFile &&
+        typeof oldSourceFile === 'object' &&
+        'kind' in oldSourceFile &&
+        typeof oldSourceFile.text === 'string' &&
+        oldSourceFile.text === docContext.tsSystem.readFile(fileName)
+    ) {
+        return false;
+    }
     return true;
 }
 

packages/svelte-check/src/index.ts

@@ -194,13 +194,17 @@ class DiagnosticsWatcher {
             .on('unlink', (path) => this.removeDocument(path))
             .on('change', (path) => this.updateDocument(path, false));
 
-        this.updateWatchedDirectories();
-        if (this.ignoreInitialAdd) {
-            getDiagnostics(this.workspaceUri, this.writer, this.svelteCheck);
-        }
+        this.updateWildcardWatcher().then(() => {
+            // ensuring the typescript program is built after wildcard watchers are added
+            // so that individual file watchers added from onFileSnapshotCreated
+            // run after the wildcard ones
+            if (this.ignoreInitialAdd) {
+                getDiagnostics(this.workspaceUri, this.writer, this.svelteCheck);
+            }
+        });
     }
 
-    private isSubdir(candidate: string, parent: string) {
+    private isSubDir(candidate: string, parent: string) {
         const c = path.resolve(candidate);
         const p = path.resolve(parent);
         return c === p || c.startsWith(p + path.sep);
@@ -210,37 +214,37 @@ class DiagnosticsWatcher {
         const sorted = [...new Set(dirs.map((d) => path.resolve(d)))].sort();
         const result: string[] = [];
         for (const dir of sorted) {
-            if (!result.some((p) => this.isSubdir(dir, p))) {
+            if (!result.some((p) => this.isSubDir(dir, p))) {
                 result.push(dir);
             }
         }
         return result;
     }
 
     addWatchDirectory(dir: string) {
-        if (!dir) return;
+        if (!dir) {
+            return;
+        }
+
         // Skip if already covered by an existing watched directory
         for (const existing of this.currentWatchedDirs) {
-            if (this.isSubdir(dir, existing)) {
+            if (this.isSubDir(dir, existing)) {
                 return;
             }
         }
-        // If new dir is a parent of existing ones, unwatch children
-        const toRemove: string[] = [];
+
+        // Don't remove existing watchers, chokidar `unwatch` ignores future events from that path instead of closing the watcher in some cases
         for (const existing of this.currentWatchedDirs) {
-            if (this.isSubdir(existing, dir)) {
-                toRemove.push(existing);
+            if (this.isSubDir(existing, dir)) {
+                this.currentWatchedDirs.delete(existing);
             }
         }
-        if (toRemove.length) {
-            this.watcher.unwatch(toRemove);
-            for (const r of toRemove) this.currentWatchedDirs.delete(r);
-        }
+
         this.watcher.add(dir);
         this.currentWatchedDirs.add(dir);
     }
 
-    private async updateWatchedDirectories() {
+    private async updateWildcardWatcher() {
         const watchDirs = await this.svelteCheck.getWatchDirectories();
         const desired = this.minimizeDirs(
             (watchDirs?.map((d) => d.path) || [this.workspaceUri.fsPath]).map((p) =>
@@ -249,15 +253,13 @@ class DiagnosticsWatcher {
         );
 
         const current = new Set([...this.currentWatchedDirs].map((p) => path.resolve(p)));
-        const desiredSet = new Set(desired);
 
         const toAdd = desired.filter((d) => !current.has(d));
-        const toRemove = [...current].filter((d) => !desiredSet.has(d));
-
-        if (toAdd.length) this.watcher.add(toAdd);
-        if (toRemove.length) this.watcher.unwatch(toRemove);
+        if (toAdd.length) {
+            this.watcher.add(toAdd);
+        }
 
-        this.currentWatchedDirs = new Set(desired);
+        this.currentWatchedDirs = new Set([...current, ...toAdd]);
     }
 
     private async updateDocument(path: string, isNew: boolean) {
@@ -280,9 +282,9 @@ class DiagnosticsWatcher {
         this.scheduleDiagnostics();
     }
 
-    updateWatchers() {
+    updateWildcardWatchers() {
         clearTimeout(this.pendingWatcherUpdate);
-        this.pendingWatcherUpdate = setTimeout(() => this.updateWatchedDirectories(), 1000);
+        this.pendingWatcherUpdate = setTimeout(() => this.updateWildcardWatcher(), 1000);
     }
 
     scheduleDiagnostics() {
@@ -342,7 +344,7 @@ parseOptions(async (opts) => {
             // Wire callbacks that can reference the watcher instance created below
             let watcher: DiagnosticsWatcher;
             svelteCheckOptions.onProjectReload = () => {
-                watcher.updateWatchers();
+                watcher.updateWildcardWatchers();
                 watcher.scheduleDiagnostics();
             };
             svelteCheckOptions.onFileSnapshotCreated = (filePath: string) => {