Mobile: Fixes #9123: Fix encryption when a resource doesn't have an associated file (#9222)

Co-authored-by: Laurent Cozic <laurent22@users.noreply.github.com>

packages/app-mobile/utils/fs-driver/fs-driver-rn.ts

@@ -9,6 +9,7 @@ import * as tar from 'tar-stream';
 import { resolve } from 'path';
 import { Buffer } from 'buffer';
 import Logger from '@joplin/utils/Logger';
+import JoplinError from '@joplin/lib/JoplinError';
 
 const logger = Logger.create('fs-driver-rn');
 
@@ -285,6 +286,10 @@ export default class FsDriverRN extends FsDriverBase {
 	}
 
 	public async readFileChunk(handle: any, length: number, rawEncoding = 'base64') {
+		if (!handle?.stat) {
+			throw new JoplinError('File does not exist (reading file chunk).', 'ENOENT');
+		}
+
 		const encoding = normalizeEncoding(rawEncoding);
 
 		if (handle.offset + length > handle.stat.size) {

packages/app-mobile/utils/fs-driver/runOnDeviceTests.ts

@@ -167,6 +167,18 @@ const testReadFileChunkUtf8 = async (tempDir: string) => {
 
 		await fsDriver.close(filePath);
 	}
+
+	// Should throw when the file doesn't exist
+	let readData = undefined;
+	try {
+		const handle = await fsDriver.open(`${filePath}.noexist`, 'r');
+		readData = await fsDriver.readFileChunk(handle, 1, 'utf8');
+	} catch (error) {
+		await expectToBe(error.code, 'ENOENT');
+	}
+
+	// Should not have read any data
+	await expectToBe(readData, undefined);
 };
 
 const testTarCreate = async (tempDir: string) => {

packages/lib/models/Resource.ts

@@ -224,7 +224,11 @@ export default class Resource extends BaseItem {
 				masterKeyId: share && share.master_key_id ? share.master_key_id : '',
 			});
 		} catch (error) {
-			if (error.code === 'ENOENT') throw new JoplinError(`File not found:${error.toString()}`, 'fileNotFound');
+			if (error.code === 'ENOENT') {
+				throw new JoplinError(
+					`Trying to encrypt resource but only metadata is present: ${error.toString()}`, 'fileNotFound',
+				);
+			}
 			throw error;
 		}