(fix) check modified time for tsconfig watching (#1973)

#1963

Author: jasonlyu123

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

@@ -53,6 +53,7 @@ const serviceSizeMap = new FileMap<number>();
 const configWatchers = new FileMap<ts.FileWatcher>();
 const extendedConfigWatchers = new FileMap<ts.FileWatcher>();
 const extendedConfigToTsConfigPath = new FileMap<FileSet>();
+const configFileModifiedTime = new FileMap<Date | undefined>();
 const configFileForOpenFiles = new FileMap<string>();
 const pendingReloads = new FileSet();
 
@@ -559,6 +560,7 @@ async function createLanguageService(
         }
 
         if (!configWatchers.has(tsconfigPath) && tsconfigPath) {
+            configFileModifiedTime.set(tsconfigPath, tsSystem.getModifiedTime?.(tsconfigPath));
             configWatchers.set(
                 tsconfigPath,
                 // for some reason setting the polling interval is necessary, else some error in TS is thrown
@@ -571,6 +573,7 @@ async function createLanguageService(
                 continue;
             }
 
+            configFileModifiedTime.set(config, tsSystem.getModifiedTime?.(config));
             extendedConfigWatchers.set(
                 config,
                 // for some reason setting the polling interval is necessary, else some error in TS is thrown
@@ -579,7 +582,18 @@ async function createLanguageService(
         }
     }
 
-    async function watchConfigCallback(fileName: string, kind: ts.FileWatcherEventKind) {
+    async function watchConfigCallback(
+        fileName: string,
+        kind: ts.FileWatcherEventKind,
+        modifiedTime: Date | undefined
+    ) {
+        if (
+            kind === ts.FileWatcherEventKind.Changed &&
+            !configFileModified(fileName, modifiedTime ?? tsSystem.getModifiedTime?.(fileName))
+        ) {
+            return;
+        }
+
         dispose();
 
         if (kind === ts.FileWatcherEventKind.Changed) {
@@ -651,7 +665,21 @@ function exceedsTotalSizeLimitForNonTsFiles(
  * So that GC won't drop it and cause memory leaks
  */
 function createWatchExtendedConfigCallback(docContext: LanguageServiceDocumentContext) {
-    return async (fileName: string) => {
+    return async (
+        fileName: string,
+        kind: ts.FileWatcherEventKind,
+        modifiedTime: Date | undefined
+    ) => {
+        if (
+            kind === ts.FileWatcherEventKind.Changed &&
+            !configFileModified(
+                fileName,
+                modifiedTime ?? docContext.tsSystem.getModifiedTime?.(fileName)
+            )
+        ) {
+            return;
+        }
+
         docContext.extendedConfigCache.delete(fileName);
 
         const promises = Array.from(extendedConfigToTsConfigPath.get(fileName) ?? []).map(
@@ -667,6 +695,23 @@ function createWatchExtendedConfigCallback(docContext: LanguageServiceDocumentCo
     };
 }
 
+/**
+ * check if file content is modified instead of attributes changed
+ */
+function configFileModified(fileName: string, modifiedTime: Date | undefined) {
+    const previousModifiedTime = configFileModifiedTime.get(fileName);
+    if (!modifiedTime || !previousModifiedTime) {
+        return true;
+    }
+
+    if (previousModifiedTime >= modifiedTime) {
+        return false;
+    }
+
+    configFileModifiedTime.set(fileName, modifiedTime);
+    return true;
+}
+
 /**
  * schedule to the service reload to the next time the
  * service in requested

packages/language-server/test/plugins/typescript/test-utils.ts

@@ -13,6 +13,7 @@ export function createVirtualTsSystem(currentDirectory: string): ts.System {
     const watchers = new FileMap<ts.FileWatcherCallback[]>();
     const watchTimeout = new FileMap<Array<ReturnType<typeof setTimeout>>>();
     const getCanonicalFileName = createGetCanonicalFileName(ts.sys.useCaseSensitiveFileNames);
+    const modifiedTime = new FileMap<Date>();
 
     function toAbsolute(path: string) {
         return isAbsolute(path) ? path : join(currentDirectory, path);
@@ -27,6 +28,7 @@ export function createVirtualTsSystem(currentDirectory: string): ts.System {
             const normalizedPath = normalizePath(toAbsolute(path));
             const existsBefore = virtualFs.has(normalizedPath);
             virtualFs.set(normalizedPath, data);
+            modifiedTime.set(normalizedPath, new Date());
             triggerWatch(
                 normalizedPath,
                 existsBefore ? ts.FileWatcherEventKind.Changed : ts.FileWatcherEventKind.Created
@@ -82,6 +84,9 @@ export function createVirtualTsSystem(currentDirectory: string): ts.System {
                     }
                 }
             };
+        },
+        getModifiedTime(path) {
+            return modifiedTime.get(normalizePath(toAbsolute(path)));
         }
     };