🐛 修正 FileSystemObserver 未能持续监听问题 (#1160)

* 修正 FileSystemObserver 未能持续监听问题

* 发生 NotFoundError 等错误时，重置 Watch File

* Update src/pkg/utils/file-tracker.ts

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* Update file-tracker.ts

* Update file-tracker.ts

* Update file-tracker.ts

---------

Co-authored-by: wangyizhi <i@xloli.top>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: 3 people

src/pages/install/App.tsx

@@ -442,6 +442,11 @@ function App() {
     }
   }
 
+  async function onWatchFileError() {
+    // e.g. NotFoundError
+    setWatchFile(false);
+  }
+
   const memoWatchFile = useMemo(() => {
     return `${watchFile}.${scriptInfo?.uuid}.${localFileHandle?.name}`;
   }, [watchFile, scriptInfo, localFileHandle]);
@@ -458,6 +463,7 @@ function App() {
         uuid,
         fileName,
         setCode: onWatchFileCodeChanged,
+        onFileError: onWatchFileError,
       };
       // 进行监听
       startFileTrack(handle, ftInfo);

src/pkg/utils/file-tracker.ts

@@ -5,30 +5,64 @@ export type FTInfo = {
   fileName: string;
   setCode(code: string, hideInfo?: boolean): void;
   lastModified?: number;
+  onFileError(): void;
+};
+
+const getHandleRecord = async (root: FileSystemFileHandle, observer: FileSystemObserverInstance) => {
+  for (const [fileHandle, ftInfo, fileObserver] of handleRecords) {
+    if (fileObserver !== observer) continue;
+    try {
+      const isSame = await root.isSameEntry(fileHandle);
+      if (isSame) {
+        return ftInfo;
+      }
+    } catch (e) {
+      // 捕捉非预期错误
+      console.warn(e);
+    }
+  }
+  return null;
 };
 
 const callback = async (records: FileSystemChangeRecord[], observer: FileSystemObserverInstance) => {
-  for (const record of records) {
-    const { root, type } = record;
-    if (!(root instanceof FileSystemFileHandle) || type !== "modified") continue;
-    for (const [fileHandle, ftInfo, fileObserver] of handleRecords) {
-      if (fileObserver !== observer) continue;
+  try {
+    for (const record of records) {
+      const { root, type } = record;
+      if (!(root instanceof FileSystemFileHandle)) continue;
+      // 只要 FileSystemObserver 侦测到档案改变，就试一下找记录和读档
+      const ftInfo = await getHandleRecord(root, observer);
+      // 如没有记录则忽略
+      if (!ftInfo) continue;
+      let file: File | null = null;
       try {
-        const isSame = await root.isSameEntry(fileHandle);
-        if (!isSame) continue;
-        // 调用安装
-        const file = await root.getFile();
-        // 避免重复更新
-        if (ftInfo.lastModified === file.lastModified) continue;
-        ftInfo.lastModified = file.lastModified;
-        const code = await file.text();
-        if (code && typeof code === "string") {
-          ftInfo.setCode(code, false);
+        const fRead = await root.getFile();
+        if (fRead && fRead.lastModified > 0 && fRead.size > 0) {
+          // 有档案内容读取权限，排除空档案
+          file = fRead;
         }
       } catch (e) {
+        // 档案改名或删掉时，或会被此捕捉（预期报错）
         console.warn(e);
+        unmountFileTrack(root);
+        ftInfo.onFileError();
+      }
+      // 如读档失败则忽略
+      if (!file) continue;
+      // 如成功读档但显示为失败，则重新 observe
+      if (type === "errored") {
+        observer.observe(root);
+      }
+      // 以 lastModified 判断避免重复更新
+      if (ftInfo.lastModified === file.lastModified) continue;
+      ftInfo.lastModified = file.lastModified;
+      const code = await file.text();
+      if (code && typeof code === "string") {
+        ftInfo.setCode(code, false);
       }
     }
+  } catch (e) {
+    // 捕捉非预期错误
+    console.warn(e);
   }
 };
 
@@ -49,6 +83,7 @@ export const unmountFileTrack = async (fileHandle: FileSystemFileHandle) => {
       }
     }
   } catch (e) {
+    // 捕捉非预期错误
     console.warn(e);
   }
   return false;