Improve error handling: catch errors and loging to FS

tshemsedinov · tshemsedinov · commit 43f99e806d84 · 2025-07-07T22:23:04.000+03:00
diff --git a/Native/static/application.js b/Native/static/application.js
@@ -1,24 +1,36 @@
+const fs = await navigator.storage.getDirectory();
+
 class Logger {
   #output;
+  #file;
+  #stream;
 
-  constructor(outputId) {
+  constructor(outputId, file) {
     this.#output = document.getElementById(outputId);
+    this.#file = file;
+    return file.createWritable().then((stream) => {
+      this.#stream = stream;
+      return this;
+    });
   }
 
   log(...args) {
     const lines = args.map(Logger.#serialize);
-    this.#output.textContent += lines.join(' ') + '\n';
+    const data = lines.join(' ') + '\n';
+    this.#output.textContent += data;
     this.#output.scrollTop = this.#output.scrollHeight;
+    const { size } = this.#file;
+    this.#stream.write({ type: 'write', position: size, data });
   }
 
   static #serialize(x) {
     return typeof x === 'object' ? JSON.stringify(x, null, 2) : x;
   }
 }
 
-const logger = new Logger('output');
-
-const fs = await navigator.storage.getDirectory();
+const logDir = await fs.getDirectoryHandle('logs', { create: true });
+const logFile = await logDir.getFileHandle('app.log', { create: true });
+const logger = await new Logger('output', logFile);
 
 const data = [
   { name: 'Marcus', age: 20 },
@@ -27,42 +39,64 @@ const data = [
 ];
 
 document.getElementById('create').onclick = async () => {
-  const fileHandle = await fs.getFileHandle('data.json', { create: true });
-  const writable = await fileHandle.createWritable();
-  await writable.write(JSON.stringify(data));
-  await writable.close();
   logger.log('File saved: data.json');
+  try {
+    const fileHandle = await fs.getFileHandle('data.json', { create: true });
+    const writable = await fileHandle.createWritable();
+    await writable.write(JSON.stringify(data));
+    await writable.close();
+  } catch (error) {
+    logger.log(error.message);
+  }
 };
 
 document.getElementById('read').onclick = async () => {
-  const fileHandle = await fs.getFileHandle('data.json');
-  const file = await fileHandle.getFile();
-  const content = await file.text();
-  logger.log(content);
-  const data = JSON.parse(content);
   logger.log('Read file: data.json');
-  logger.log(data);
+  try {
+    const fileHandle = await fs.getFileHandle('data.json');
+    const file = await fileHandle.getFile();
+    const content = await file.text();
+    logger.log(content);
+    const data = JSON.parse(content);
+    logger.log(data);
+  } catch (error) {
+    logger.log(error.message);
+  }
 };
 
 document.getElementById('append').onclick = async () => {
-  const fileHandle = await fs.getFileHandle('data.json', { create: true });
-  const writable = await fileHandle.createWritable({ keepExistingData: true });
-  const file = await fileHandle.getFile();
-  const marcus = { name: 'Marcus', age: 20 };
-  const buffer = ',' + JSON.stringify(marcus) + ']';
-  logger.log(buffer);
-  await writable.write({ type: 'write', position: file.size - 1, buffer });
-  await writable.close();
   logger.log('Append to: data.json');
+  try {
+    const fileHandle = await fs.getFileHandle('data.json', { create: true });
+    const writable = await fileHandle.createWritable({
+      keepExistingData: true,
+    });
+    const file = await fileHandle.getFile();
+    const marcus = { name: 'Marcus', age: 20 };
+    const data = `,${JSON.stringify(marcus)}]`;
+    await writable.write({ type: 'write', position: file.size - 1, data });
+    await writable.close();
+  } catch (error) {
+    logger.log(error.message);
+  }
 };
 
 document.getElementById('list').onclick = async () => {
-  for await (const [name, handle] of fs.entries()) {
-    logger.log(`${name} ${handle.kind}`);
+  logger.log('List files:');
+  try {
+    for await (const [name, handle] of fs.entries()) {
+      logger.log(`${name} ${handle.kind}`);
+    }
+  } catch (error) {
+    logger.log(error.message);
   }
 };
 
 document.getElementById('delete').onclick = async () => {
-  await fs.removeEntry('data.json');
   logger.log('Deleted: data.json');
+  try {
+    await fs.removeEntry('data.json');
+  } catch (error) {
+    logger.log(error.message);
+  }
 };
diff --git a/README.md b/README.md
@@ -1,4 +1,4 @@
-## Origin private file system
+## Origin Private File System
 
 > Usage Examples and Wrappers
 

Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-## Origin private file system`
	`1`	`+## Origin Private File System`
`2`	`2`
`3`	`3`	`> Usage Examples and Wrappers`
`4`	`4`