Chore: Mobile: Update fsDriver in preparation for mobile plugins (#10066)

.eslintignore

@@ -582,8 +582,16 @@ packages/app-mobile/utils/autodetectTheme.js
 packages/app-mobile/utils/checkPermissions.js
 packages/app-mobile/utils/createRootStyle.js
 packages/app-mobile/utils/debounce.js
+packages/app-mobile/utils/fs-driver/constants.js
 packages/app-mobile/utils/fs-driver/fs-driver-rn.js
 packages/app-mobile/utils/fs-driver/runOnDeviceTests.js
+packages/app-mobile/utils/fs-driver/tarCreate.js
+packages/app-mobile/utils/fs-driver/tarExtract.test.js
+packages/app-mobile/utils/fs-driver/tarExtract.js
+packages/app-mobile/utils/fs-driver/testUtil/createFilesFromPathRecord.js
+packages/app-mobile/utils/fs-driver/testUtil/verifyDirectoryMatches.js
+packages/app-mobile/utils/polyfills/bufferPolyfill.js
+packages/app-mobile/utils/polyfills/index.js
 packages/app-mobile/utils/setupNotifications.js
 packages/app-mobile/utils/shareHandler.js
 packages/app-mobile/utils/types.js

.gitignore

@@ -562,8 +562,16 @@ packages/app-mobile/utils/autodetectTheme.js
 packages/app-mobile/utils/checkPermissions.js
 packages/app-mobile/utils/createRootStyle.js
 packages/app-mobile/utils/debounce.js
+packages/app-mobile/utils/fs-driver/constants.js
 packages/app-mobile/utils/fs-driver/fs-driver-rn.js
 packages/app-mobile/utils/fs-driver/runOnDeviceTests.js
+packages/app-mobile/utils/fs-driver/tarCreate.js
+packages/app-mobile/utils/fs-driver/tarExtract.test.js
+packages/app-mobile/utils/fs-driver/tarExtract.js
+packages/app-mobile/utils/fs-driver/testUtil/createFilesFromPathRecord.js
+packages/app-mobile/utils/fs-driver/testUtil/verifyDirectoryMatches.js
+packages/app-mobile/utils/polyfills/bufferPolyfill.js
+packages/app-mobile/utils/polyfills/index.js
 packages/app-mobile/utils/setupNotifications.js
 packages/app-mobile/utils/shareHandler.js
 packages/app-mobile/utils/types.js

packages/app-mobile/index.js

@@ -6,9 +6,7 @@
 
 // So there's basically still a one way flux: React => SQLite => Redux => React
 
-// For aws-sdk-js-v3
-import 'react-native-get-random-values';
-import 'react-native-url-polyfill/auto';
+import './utils/polyfills';
 
 import { LogBox, AppRegistry } from 'react-native';
 const Root = require('./root').default;

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

@@ -0,0 +1,4 @@
+
+// Maximum/expected size of part of a file to be read
+// eslint-disable-next-line import/prefer-default-export
+export const chunkSize = 1024 * 100; // 100 KiB

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

@@ -3,13 +3,12 @@ const RNFetchBlob = require('rn-fetch-blob').default;
 import * as RNFS from 'react-native-fs';
 import RNSAF, { DocumentFileDetail, openDocumentTree } from '@joplin/react-native-saf-x';
 import { Platform } from 'react-native';
-import * as tar from 'tar-stream';
-import { resolve } from 'path';
-import { Buffer } from 'buffer';
-import Logger from '@joplin/utils/Logger';
+import tarCreate from './tarCreate';
+import tarExtract from './tarExtract';
 import JoplinError from '@joplin/lib/JoplinError';
+const md5 = require('md5');
+import { resolve } from 'path';
 
-const logger = Logger.create('fs-driver-rn');
 
 const ANDROID_URI_PREFIX = 'content://';
 
@@ -51,7 +50,7 @@ const normalizeEncoding = (encoding: string): SupportedEncoding => {
 
 export default class FsDriverRN extends FsDriverBase {
 	public appendFileSync() {
-		throw new Error('Not implemented');
+		throw new Error('Not implemented: appendFileSync');
 	}
 
 	// Requires that the file already exists.
@@ -212,7 +211,7 @@ export default class FsDriverRN extends FsDriverBase {
 		// return RNFS.touch(path, timestampDate, timestampDate);
 	}
 
-	public async open(path: string, mode: number) {
+	public async open(path: string, mode: string) {
 		if (isScopedUri(path)) {
 			throw new Error('open() not implemented in FsDriverAndroid');
 		}
@@ -228,7 +227,7 @@ export default class FsDriverRN extends FsDriverBase {
 		};
 	}
 
-	public close(): Promise<void> {
+	public close(_handle: any): Promise<void> {
 		// Nothing
 		return null;
 	}
@@ -302,58 +301,31 @@ export default class FsDriverRN extends FsDriverBase {
 	}
 
 	public resolve(...paths: string[]): string {
-		throw new Error(`Not implemented: resolve(): ${JSON.stringify(paths)}`);
+		return resolve(...paths);
 	}
 
 	public async md5File(path: string): Promise<string> {
-		throw new Error(`Not implemented: md5File(): ${path}`);
+		if (isScopedUri(path)) {
+			// Warning: Slow
+			const fileData = Buffer.from(await this.readFile(path, 'base64'), 'base64');
+			return md5(fileData);
+		} else {
+			return await RNFS.hash(path, 'md5');
+		}
 	}
 
-	public async tarExtract(_options: any) {
-		throw new Error('Not implemented: tarExtract');
+	public async tarExtract(options: any) {
+		await tarExtract({
+			cwd: RNFS.DocumentDirectoryPath,
+			...options,
+		});
 	}
 
 	public async tarCreate(options: any, filePaths: string[]) {
-		// Choose a default cwd if not given
-		const cwd = options.cwd ?? RNFS.DocumentDirectoryPath;
-		const file = resolve(cwd, options.file);
-
-		if (await this.exists(file)) {
-			throw new Error('Error! Destination already exists');
-		}
-
-		const pack = tar.pack();
-
-		for (const path of filePaths) {
-			const absPath = resolve(cwd, path);
-			const stat = await this.stat(absPath);
-			const sizeBytes: number = stat.size;
-
-			const entry = pack.entry({ name: path, size: sizeBytes }, (error) => {
-				if (error) {
-					logger.error(`Tar error: ${error}`);
-				}
-			});
-
-			const chunkSize = 1024 * 100; // 100 KiB
-			for (let offset = 0; offset < sizeBytes; offset += chunkSize) {
-				// The RNFS documentation suggests using base64 for binary files.
-				const part = await RNFS.read(absPath, chunkSize, offset, 'base64');
-				entry.write(Buffer.from(part, 'base64'));
-			}
-			entry.end();
-		}
-
-		pack.finalize();
-
-		// The streams used by tar-stream seem not to support a chunk size
-		// (it seems despite the typings provided).
-		let data: number[]|null = null;
-		while ((data = pack.read()) !== null) {
-			const buff = Buffer.from(data);
-			const base64Data = buff.toString('base64');
-			await this.appendFile(file, base64Data, 'base64');
-		}
+		await tarCreate({
+			cwd: RNFS.DocumentDirectoryPath,
+			...options,
+		}, filePaths);
 	}
 
 	public async getExternalDirectoryPath(): Promise<string | undefined> {

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

@@ -5,6 +5,8 @@ import { join } from 'path';
 import FsDriverBase from '@joplin/lib/fs-driver-base';
 import Logger from '@joplin/utils/Logger';
 import { Buffer } from 'buffer';
+import createFilesFromPathRecord from './testUtil/createFilesFromPathRecord';
+import verifyDirectoryMatches from './testUtil/verifyDirectoryMatches';
 
 const logger = Logger.create('fs-driver-tests');
 
@@ -181,7 +183,7 @@ const testReadFileChunkUtf8 = async (tempDir: string) => {
 	await expectToBe(readData, undefined);
 };
 
-const testTarCreate = async (tempDir: string) => {
+const testTarCreateAndExtract = async (tempDir: string) => {
 	logger.info('Testing fsDriver.tarCreate...');
 
 	const directoryToPack = join(tempDir, uuid.createNano());
@@ -193,34 +195,31 @@ const testTarCreate = async (tempDir: string) => {
 
 	// small utf-8 encoded files
 	for (let i = 0; i < 10; i ++) {
-		const testFilePath = join(directoryToPack, uuid.createNano());
-
+		const testFileName = uuid.createNano();
 		const fileContent = `✅ Testing... ä ✅ File #${i}`;
-		await fsDriver.writeFile(testFilePath, fileContent, 'utf-8');
 
-		fileContents[testFilePath] = fileContent;
+		fileContents[testFileName] = fileContent;
 	}
 
 	// larger utf-8 encoded files
 	for (let i = 0; i < 3; i ++) {
-		const testFilePath = join(directoryToPack, uuid.createNano());
+		const testFileName = uuid.createNano();
 
 		let fileContent = `✅ Testing... ä ✅ File #${i}`;
-
 		for (let j = 0; j < 8; j ++) {
 			fileContent += fileContent;
 		}
 
-		await fsDriver.writeFile(testFilePath, fileContent, 'utf-8');
-
-		fileContents[testFilePath] = fileContent;
+		fileContents[testFileName] = fileContent;
 	}
 
+	await createFilesFromPathRecord(directoryToPack, fileContents);
+
 	// Pack the files
 	const pathsToTar = Object.keys(fileContents);
 	const tarOutputPath = join(tempDir, 'test-tar.tar');
 	await fsDriver.tarCreate({
-		cwd: tempDir,
+		cwd: directoryToPack,
 		file: tarOutputPath,
 	}, pathsToTar);
 
@@ -231,6 +230,27 @@ const testTarCreate = async (tempDir: string) => {
 	for (const fileContent of Object.values(fileContents)) {
 		await expectToBe(rawTarData.includes(fileContent), true);
 	}
+
+	logger.info('Testing fsDriver.tarExtract...');
+
+	const outputDirectory = join(tempDir, uuid.createNano());
+	await fsDriver.mkdir(outputDirectory);
+	await fsDriver.tarExtract({
+		cwd: outputDirectory,
+		file: tarOutputPath,
+	});
+
+	await verifyDirectoryMatches(outputDirectory, fileContents);
+};
+
+const testMd5File = async (tempDir: string) => {
+	logger.info('Testing fsDriver.md5file...');
+	const fsDriver = shim.fsDriver();
+
+	const testFilePath = join(tempDir, `test-md5-${uuid.createNano()}`);
+	await fsDriver.writeFile(testFilePath, '🚧test', 'utf8');
+
+	await expectToBe(await fsDriver.md5File(testFilePath), 'ba11ba1be5042133a71874731e3d42cd');
 };
 
 // In the past, some fs-driver functionality has worked correctly on some devices and not others.
@@ -247,7 +267,10 @@ const runOnDeviceTests = async () => {
 		await testAppendFile(tempDir);
 		await testReadWriteFileUtf8(tempDir);
 		await testReadFileChunkUtf8(tempDir);
-		await testTarCreate(tempDir);
+		await testTarCreateAndExtract(tempDir);
+		await testMd5File(tempDir);
+
+		logger.info('Done');
 	} catch (error) {
 		const errorMessage = `On-device testing failed with an exception: ${error}.`;
 

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

@@ -0,0 +1,62 @@
+import { pack as tarStreamPack } from 'tar-stream';
+import { resolve } from 'path';
+import * as RNFS from 'react-native-fs';
+
+import Logger from '@joplin/utils/Logger';
+import { chunkSize } from './constants';
+import shim from '@joplin/lib/shim';
+
+const logger = Logger.create('fs-driver-rn');
+
+interface TarCreateOptions {
+	cwd: string;
+	file: string;
+}
+
+// TODO: Support glob patterns, which are currently supported by the
+//       node fsDriver.
+
+const tarCreate = async (options: TarCreateOptions, filePaths: string[]) => {
+	// Choose a default cwd if not given
+	const cwd = options.cwd ?? RNFS.DocumentDirectoryPath;
+	const file = resolve(cwd, options.file);
+
+	const fsDriver = shim.fsDriver();
+	if (await fsDriver.exists(file)) {
+		throw new Error('Error! Destination already exists');
+	}
+
+	const pack = tarStreamPack();
+
+	for (const path of filePaths) {
+		const absPath = resolve(cwd, path);
+		const stat = await fsDriver.stat(absPath);
+		const sizeBytes: number = stat.size;
+
+		const entry = pack.entry({ name: path, size: sizeBytes }, (error) => {
+			if (error) {
+				logger.error(`Tar error: ${error}`);
+			}
+		});
+
+		for (let offset = 0; offset < sizeBytes; offset += chunkSize) {
+			// The RNFS documentation suggests using base64 for binary files.
+			const part = await RNFS.read(absPath, chunkSize, offset, 'base64');
+			entry.write(Buffer.from(part, 'base64'));
+		}
+		entry.end();
+	}
+
+	pack.finalize();
+
+	// The streams used by tar-stream seem not to support a chunk size
+	// (it seems despite the typings provided).
+	let data: number[]|null = null;
+	while ((data = pack.read()) !== null) {
+		const buff = Buffer.from(data);
+		const base64Data = buff.toString('base64');
+		await fsDriver.appendFile(file, base64Data, 'base64');
+	}
+};
+
+export default tarCreate;

packages/app-mobile/utils/fs-driver/tarExtract.test.ts

@@ -0,0 +1,65 @@
+
+// tarExtract has tests both in runOnDeviceTests and here.
+// Just Jest tests aren't sufficient in this case because, in the past, differences
+// between polyfilled and node-built-in libraries have caused issues.
+
+import shim from '@joplin/lib/shim';
+import { createTempDir } from '@joplin/lib/testing/test-utils';
+import { join } from 'path';
+import createFilesFromPathRecord from './testUtil/createFilesFromPathRecord';
+import verifyDirectoryMatches from './testUtil/verifyDirectoryMatches';
+import tarExtract from './tarExtract';
+import { remove } from 'fs-extra';
+
+
+const verifyTarWithContentExtractsTo = async (filePaths: Record<string, string>) => {
+	const tempDir = await createTempDir();
+
+	try {
+		const sourceDirectory = join(tempDir, 'source');
+		await createFilesFromPathRecord(sourceDirectory, filePaths);
+
+		const tarOutputFile = join(tempDir, 'test.tar');
+		// Uses node tar during testing
+		await shim.fsDriver().tarCreate(
+			{ cwd: sourceDirectory, file: tarOutputFile }, Object.keys(filePaths),
+		);
+
+		const outputDirectory = join(tempDir, 'dest');
+		await tarExtract({
+			cwd: outputDirectory,
+			file: tarOutputFile,
+		});
+
+		await verifyDirectoryMatches(outputDirectory, filePaths);
+	} finally {
+		await remove(tempDir);
+	}
+};
+
+describe('tarExtract', () => {
+	it('should extract a tar with a single file', async () => {
+		await verifyTarWithContentExtractsTo({
+			'a.txt': 'Test',
+		});
+	});
+
+	it('should extract tar files containing unicode characters', async () => {
+		await verifyTarWithContentExtractsTo({
+			'a.txt': 'Test✅',
+			'b/á-test.txt': 'Test letters: ϑ, ó, ö, ś',
+			'c/á-test.txt': 'This also works.',
+		});
+	});
+
+	it('should extract tar files with deeply nested subdirectories', async () => {
+		await verifyTarWithContentExtractsTo({
+			'a.txt': 'Test✅',
+			'b/c/d/e/f/test-Ó.txt': 'Test letters: ϑ, ó, ö, ś',
+			'b/c/d/e/f/test2.txt': 'This works.',
+			'b/test3.txt': 'This also works.',
+			'b/test4.txt': 'This also works...',
+			'b/c/test4.txt': 'This also works.',
+		});
+	});
+});

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

@@ -0,0 +1,92 @@
+import { extract as tarStreamExtract } from 'tar-stream';
+import { resolve, dirname } from 'path';
+import shim from '@joplin/lib/shim';
+import { chunkSize } from './constants';
+
+interface TarExtractOptions {
+	cwd: string;
+	file: string;
+}
+
+const tarExtract = async (options: TarExtractOptions) => {
+	const cwd = options.cwd;
+
+	// resolve doesn't correctly handle file:// or content:// URLs. Thus, we don't resolve relative
+	// to cwd if the source is a URL.
+	const isSourceUrl = options.file.match(/$[a-z]+:\/\//);
+	const filePath = isSourceUrl ? options.file : resolve(cwd, options.file);
+
+	const fsDriver = shim.fsDriver();
+	if (!(await fsDriver.exists(filePath))) {
+		throw new Error('tarExtract: Source file does not exist');
+	}
+
+	const extract = tarStreamExtract({ defaultEncoding: 'base64' });
+
+	extract.on('entry', async (header, stream, next) => {
+		const outPath = fsDriver.resolveRelativePathWithinDir(cwd, header.name);
+
+		if (await fsDriver.exists(outPath)) {
+			throw new Error(`Extracting ${outPath} would overwrite`);
+		}
+
+		// Move to the next item when all available data has been read.
+		stream.once('end', () => next());
+
+		if (header.type === 'directory') {
+			await fsDriver.mkdir(outPath);
+		} else if (header.type === 'file') {
+			const parentDir = dirname(outPath);
+			await fsDriver.mkdir(parentDir);
+
+			await fsDriver.appendBinaryReadableToFile(outPath, stream);
+		} else {
+			throw new Error(`Unsupported file system entity type: ${header.type}`);
+		}
+
+		// Drain the rest of the stream.
+		stream.resume();
+
+	});
+
+	let finished = false;
+	const finishPromise = new Promise<void>((resolve, reject) => {
+		extract.once('finish', () => {
+			finished = true;
+			resolve();
+		});
+
+		extract.once('error', (error) => {
+			reject(error);
+		});
+	});
+
+	const fileHandle = await fsDriver.open(filePath, 'r');
+	const readChunk = async () => {
+		const base64 = await fsDriver.readFileChunk(fileHandle, chunkSize, 'base64');
+		return base64 && Buffer.from(base64, 'base64');
+	};
+
+	try {
+		let chunk = await readChunk();
+		let nextChunk = await readChunk();
+		do {
+			extract.write(chunk);
+
+			chunk = nextChunk;
+			nextChunk = await readChunk();
+		} while (nextChunk !== null && !finished);
+
+		if (chunk !== null) {
+			extract.end(chunk);
+		} else {
+			extract.end();
+		}
+	} finally {
+		await fsDriver.close(fileHandle);
+	}
+
+	await finishPromise;
+};
+
+export default tarExtract;

packages/app-mobile/utils/fs-driver/testUtil/createFilesFromPathRecord.ts

@@ -0,0 +1,13 @@
+
+import shim from '@joplin/lib/shim';
+import { join, dirname } from 'path';
+
+const createFilesFromPathRecord = async (baseDir: string, fileContents: Record<string, string>) => {
+	for (const relativePath in fileContents) {
+		const targetPath = join(baseDir, relativePath);
+		await shim.fsDriver().mkdir(dirname(targetPath));
+		await shim.fsDriver().writeFile(targetPath, fileContents[relativePath], 'utf-8');
+	}
+};
+
+export default createFilesFromPathRecord;

packages/app-mobile/utils/fs-driver/testUtil/verifyDirectoryMatches.ts

@@ -0,0 +1,22 @@
+
+import shim from '@joplin/lib/shim';
+import { join } from 'path';
+
+const verifyDirectoryMatches = async (baseDir: string, fileContents: Record<string, string>) => {
+	for (const path in fileContents) {
+		const fileContent = await shim.fsDriver().readFile(join(baseDir, path), 'utf8');
+		const expectedContent = fileContents[path];
+		if (fileContent !== fileContents[path]) {
+			throw new Error(`File ${path} content mismatch. Was ${JSON.stringify(fileContent)}, expected ${JSON.stringify(expectedContent)}.`);
+		}
+	}
+
+	const dirStats = await shim.fsDriver().readDirStats(baseDir, { recursive: true });
+	for (const stat of dirStats) {
+		if (!stat.isDirectory() && !(stat.path in fileContents)) {
+			throw new Error(`Unexpected file with path ${stat.path} found.`);
+		}
+	}
+};
+
+export default verifyDirectoryMatches;

packages/app-mobile/utils/polyfills/bufferPolyfill.ts

@@ -0,0 +1,15 @@
+
+import { Buffer } from 'buffer';
+
+// Fix the subarray method.
+// TODO: Remove this after https://github.com/feross/buffer/issues/329 is closed
+const originalSubarray = Buffer.prototype.subarray;
+Buffer.prototype.subarray = function(start: number, end: number) {
+	const subarray = originalSubarray.call(this, start, end);
+	Object.setPrototypeOf(subarray, Buffer.prototype);
+	return subarray;
+};
+
+// TODO: Remove this "disable-next-line" after eslint supports globalThis.
+// eslint-disable-next-line no-undef
+globalThis.Buffer = Buffer;

packages/app-mobile/utils/polyfills/index.ts

@@ -0,0 +1,5 @@
+import './bufferPolyfill';
+
+// For aws-sdk-js-v3
+import 'react-native-get-random-values';
+import 'react-native-url-polyfill/auto';

packages/lib/fs-driver-base.ts

@@ -2,6 +2,7 @@ import time from './time';
 import Setting from './models/Setting';
 import { filename, fileExtension } from './path-utils';
 const md5 = require('md5');
+import { Buffer } from 'buffer';
 
 export interface Stat {
 	birthtime: Date;
@@ -18,35 +19,36 @@ export interface ReadDirStatsOptions {
 export default class FsDriverBase {
 
 	public async stat(_path: string): Promise<Stat> {
-		throw new Error('Not implemented');
+		throw new Error('Not implemented: stat()');
 	}
 
 	public async readFile(_path: string, _encoding = 'utf8'): Promise<any> {
-		throw new Error('Not implemented');
+		throw new Error('Not implemented: readFile');
 	}
 
 	public async appendFile(_path: string, _content: string, _encoding = 'base64'): Promise<any> {
-		throw new Error('Not implemented');
+		throw new Error('Not implemented: appendFile');
 	}
 
 	public async copy(_source: string, _dest: string) {
-		throw new Error('Not implemented');
+		throw new Error('Not implemented: copy');
 	}
 
 	public async chmod(_source: string, _mode: string | number) {
-		throw new Error('Not implemented');
+		throw new Error('Not implemented: chmod');
 	}
 
+	// Must also create parent directories
 	public async mkdir(_path: string) {
-		throw new Error('Not implemented');
+		throw new Error('Not implemented: mkdir');
 	}
 
 	public async unlink(_path: string) {
-		throw new Error('Not implemented');
+		throw new Error('Not implemented: unlink');
 	}
 
 	public async move(_source: string, _dest: string) {
-		throw new Error('Not implemented');
+		throw new Error('Not implemented: move');
 	}
 
 	public async rename(source: string, dest: string) {
@@ -54,27 +56,27 @@ export default class FsDriverBase {
 	}
 
 	public async readFileChunk(_handle: any, _length: number, _encoding = 'base64'): Promise<string> {
-		throw new Error('Not implemented');
+		throw new Error('Not implemented: readFileChunk');
 	}
 
 	public async open(_path: string, _mode: any): Promise<any> {
-		throw new Error('Not implemented');
+		throw new Error('Not implemented: open');
 	}
 
 	public async close(_handle: any): Promise<any> {
-		throw new Error('Not implemented');
+		throw new Error('Not implemented: close');
 	}
 
 	public async readDirStats(_path: string, _options: ReadDirStatsOptions = null): Promise<Stat[]> {
-		throw new Error('Not implemented');
+		throw new Error('Not implemented: readDirStats');
 	}
 
 	public async exists(_path: string): Promise<boolean> {
-		throw new Error('Not implemented');
+		throw new Error('Not implemented: exists');
 	}
 
 	public async remove(_path: string): Promise<void> {
-		throw new Error('Not implemented');
+		throw new Error('Not implemented: remove');
 	}
 
 	public async isDirectory(path: string) {
@@ -94,8 +96,14 @@ export default class FsDriverBase {
 		throw new Error('Not implemented: resolve');
 	}
 
-	public resolveRelativePathWithinDir(_baseDir: string, relativePath: string): string {
-		throw new Error(`Not implemented: resolveRelativePathWithinDir(): ${relativePath}`);
+	// Resolves the provided relative path to an absolute path within baseDir. The function
+	// also checks that the absolute path is within baseDir, to avoid security issues.
+	// It is expected that baseDir is a safe path (not user-provided).
+	public resolveRelativePathWithinDir(baseDir: string, relativePath: string) {
+		const resolvedBaseDir = this.resolve(baseDir);
+		const resolvedPath = this.resolve(baseDir, relativePath);
+		if (resolvedPath.indexOf(resolvedBaseDir) !== 0) throw new Error(`Resolved path for relative path "${relativePath}" is not within base directory "${baseDir}" (Was resolved to ${resolvedPath})`);
+		return resolvedPath;
 	}
 
 	public getExternalDirectoryPath(): Promise<string | undefined> {
@@ -106,6 +114,15 @@ export default class FsDriverBase {
 		return false;
 	}
 
+	public async appendBinaryReadableToFile(path: string, readable: { read(): number[]|null }) {
+		let data: number[]|null = null;
+		while ((data = readable.read()) !== null) {
+			const buff = Buffer.from(data);
+			const base64Data = buff.toString('base64');
+			await this.appendFile(path, base64Data, 'base64');
+		}
+	}
+
 	protected async readDirStatsHandleRecursion_(basePath: string, stat: Stat, output: Stat[], options: ReadDirStatsOptions): Promise<Stat[]> {
 		if (options.recursive && stat.isDirectory()) {
 			const subPath = `${basePath}/${stat.path}`;
@@ -187,11 +204,11 @@ export default class FsDriverBase {
 	}
 
 	public async tarExtract(_options: any) {
-		throw new Error('Not implemented');
+		throw new Error('Not implemented: tarExtract');
 	}
 
 	public async tarCreate(_options: any, _filePaths: string[]) {
-		throw new Error('Not implemented');
+		throw new Error('Not implemented: tarCreate');
 	}
 
 }

packages/lib/fs-driver-node.ts

@@ -1,4 +1,3 @@
-import { resolve as nodeResolve } from 'path';
 import FsDriverBase, { Stat } from './fs-driver-base';
 import time from './time';
 const md5File = require('md5-file');
@@ -84,7 +83,7 @@ export default class FsDriverNode extends FsDriverBase {
 		return r;
 	}
 
-	public async stat(path: string) {
+	public async stat(path: string): Promise<Stat> {
 		try {
 			const stat = await fs.stat(path);
 			return {
@@ -186,18 +185,8 @@ export default class FsDriverNode extends FsDriverBase {
 		throw new Error(`Unsupported encoding: ${encoding}`);
 	}
 
-	public resolve(path: string) {
-		return require('path').resolve(path);
-	}
-
-	// Resolves the provided relative path to an absolute path within baseDir. The function
-	// also checks that the absolute path is within baseDir, to avoid security issues.
-	// It is expected that baseDir is a safe path (not user-provided).
-	public resolveRelativePathWithinDir(baseDir: string, relativePath: string) {
-		const resolvedBaseDir = nodeResolve(baseDir);
-		const resolvedPath = nodeResolve(baseDir, relativePath);
-		if (resolvedPath.indexOf(resolvedBaseDir) !== 0) throw new Error(`Resolved path for relative path "${relativePath}" is not within base directory "${baseDir}" (Was resolved to ${resolvedPath})`);
-		return resolvedPath;
+	public resolve(...pathComponents: string[]) {
+		return require('path').resolve(...pathComponents);
 	}
 
 	public async md5File(path: string): Promise<string> {