Overhaul filesystem operations

- Added `Switch.mkdirSync()`, `Switch.removeSync()`, `Switch.statSync()`
- Read operations return `null` for `ENOENT`, instead of throwing an error
- `Switch.remove()` and `Switch.removeSync()` work with directories, and delete recursively
- `Switch.writeFileSync()` creates parent directories recursively as needed

.changeset/perfect-pugs-smell.md

@@ -0,0 +1,10 @@
+---
+'nxjs-runtime': patch
+---
+
+Overhaul filesystem operations:
+
+ * Added `Switch.mkdirSync()`, `Switch.removeSync()`, `Switch.statSync()`
+ * Read operations return `null` for `ENOENT`, instead of throwing an error
+ * `Switch.remove()` and `Switch.removeSync()` work with directories, and delete recursively
+ * `Switch.writeFileSync()` creates parent directories recursively as needed

apps/tests/src/switch.ts

@@ -41,14 +41,16 @@ test('`Switch.readDirSync()` works on `romfs:/` path', () => {
 	assert.ok(files.length > 0);
 });
 
-test('`Switch.readDirSync()` throws error when directory does not exist', () => {
-	let err: Error | undefined;
-	try {
-		Switch.readDirSync('romfs:/__does_not_exist__');
-	} catch (_err) {
-		err = _err as Error;
-	}
-	assert.ok(err);
+test('`Switch.readFileSync()` returns `null` when file does not exist', () => {
+	assert.equal(Switch.readFileSync('romfs:/__does_not_exist__'), null);
+});
+
+test('`Switch.readDirSync()` returns `null` when directory does not exist', () => {
+	assert.equal(Switch.readDirSync('romfs:/__does_not_exist__'), null);
+});
+
+test('`Switch.statSync()` returns `null` when file does not exist', () => {
+	assert.equal(Switch.statSync('romfs:/__does_not_exist__'), null);
 });
 
 test('`Switch.resolveDns()` works', async () => {

packages/runtime/src/$.ts

@@ -109,12 +109,15 @@ export interface Init {
 	getSystemFont(): ArrayBuffer;
 
 	// fs.c
-	readFile(cb: Callback<ArrayBuffer>, path: string): void;
-	readDirSync(path: string): string[];
-	readFileSync(path: string): ArrayBuffer;
-	writeFileSync(path: string, data: ArrayBuffer): void;
+	mkdirSync(path: string, mode: number): number;
+	readDirSync(path: string): string[] | null;
+	readFile(cb: Callback<ArrayBuffer | null>, path: string): void;
+	readFileSync(path: string): ArrayBuffer | null;
 	remove(cb: Callback<void>, path: string): void;
-	stat(cb: Callback<Stats>, path: string): void;
+	removeSync(path: string): void;
+	stat(cb: Callback<Stats | null>, path: string): void;
+	statSync(path: string): Stats | null;
+	writeFileSync(path: string, data: ArrayBuffer): void;
 
 	// image.c
 	imageInit(c: ClassOf<Image | ImageBitmap>): void;

packages/runtime/src/fetch/fetch.ts

@@ -230,11 +230,14 @@ async function fetchFile(req: Request, url: URL) {
 	const path = url.protocol === 'file:' ? `sdmc:${url.pathname}` : url.href;
 	// TODO: Use streaming FS interface
 	const data = await readFile(path);
-	return new Response(data, {
-		headers: {
-			'content-length': String(data.byteLength),
-		},
-	});
+	const headers = new Headers();
+	let status = 200;
+	if (data) {
+		headers.set('content-length', String(data.byteLength));
+	} else {
+		status = 404;
+	}
+	return new Response(data, { status, headers });
 }
 
 const fetchers = new Map<string, (req: Request, url: URL) => Promise<Response>>(

packages/runtime/src/fs.ts

@@ -3,6 +3,25 @@ import { bufferSourceToArrayBuffer, pathToString, toPromise } from './utils';
 import { encoder } from './polyfills/text-encoder';
 import type { PathLike } from './switch';
 
+/**
+ * Creates the directory at the provided `path`, as well as any necessary parent directories.
+ *
+ * @example
+ *
+ * ```typescript
+ * const count = Switch.mkdirSync('sdmc:/foo/bar/baz');
+ * console.log(`Created ${count} directories`);
+ * // Created 3 directories
+ * ```
+ *
+ * @param path Path of the directory to create.
+ * @param mode The file mode to set for the directories. Default: `0o777`.
+ * @returns The number of directories created. If the directory already exists, returns `0`.
+ */
+export function mkdirSync(path: PathLike, mode = 0o777) {
+	return $.mkdirSync(pathToString(path), mode);
+}
+
 /**
  * Returns a Promise which resolves to an `ArrayBuffer` containing
  * the contents of the file at `path`.
@@ -51,6 +70,8 @@ export function readFileSync(path: PathLike) {
 /**
  * Synchronously writes the contents of `data` to the file at `path`.
  *
+ * @example
+ *
  * ```typescript
  * const appStateJson = JSON.stringify(appState);
  * Switch.writeFileSync('sdmc:/switch/awesome-app/state.json', appStateJson);
@@ -63,15 +84,37 @@ export function writeFileSync(path: PathLike, data: string | BufferSource) {
 }
 
 /**
- * Removes the file or directory specified by `path`.
+ * Synchronously removes the file or directory recursively specified by `path`.
+ *
+ * @param path File path to remove.
+ */
+export function removeSync(path: PathLike) {
+	return $.removeSync(pathToString(path));
+}
+
+/**
+ * Removes the file or directory recursively specified by `path`.
+ *
+ * @param path File path to remove.
  */
 export function remove(path: PathLike) {
 	return toPromise($.remove, pathToString(path));
 }
 
+/**
+ *
+ * @param path File path to retrieve file stats for.
+ * @returns Object containing the file stat information of `path`, or `null` if the file does not exist.
+ */
+export function statSync(path: PathLike) {
+	return $.statSync(pathToString(path));
+}
+
 /**
  * Returns a Promise which resolves to an object containing
  * information about the file pointed to by `path`.
+ *
+ * @param path File path to retrieve file stats for.
  */
 export function stat(path: PathLike) {
 	return toPromise($.stat, pathToString(path));

packages/runtime/src/source-map.ts

@@ -51,25 +51,31 @@ function filenameToTracer(filename: string) {
 	tracer = null;
 
 	const contentsBuffer = readFileSync(filename);
-	const contents = new TextDecoder().decode(contentsBuffer).trimEnd();
-	const lastNewline = contents.lastIndexOf('\n');
-	const lastLine = contents.slice(lastNewline + 1);
-	if (lastLine.startsWith(SOURCE_MAPPING_URL_PREFIX)) {
-		const sourceMappingURL = lastLine.slice(
-			SOURCE_MAPPING_URL_PREFIX.length
-		);
-		let sourceMapBuffer: ArrayBuffer;
-		if (sourceMappingURL.startsWith('data:')) {
-			sourceMapBuffer = dataUriToBuffer(sourceMappingURL).buffer;
-		} else {
-			sourceMapBuffer = readFileSync(new URL(sourceMappingURL, filename));
+	if (contentsBuffer) {
+		const contents = new TextDecoder().decode(contentsBuffer).trimEnd();
+		const lastNewline = contents.lastIndexOf('\n');
+		const lastLine = contents.slice(lastNewline + 1);
+		if (lastLine.startsWith(SOURCE_MAPPING_URL_PREFIX)) {
+			const sourceMappingURL = lastLine.slice(
+				SOURCE_MAPPING_URL_PREFIX.length
+			);
+			let sourceMapBuffer: ArrayBuffer | null;
+			if (sourceMappingURL.startsWith('data:')) {
+				sourceMapBuffer = dataUriToBuffer(sourceMappingURL).buffer;
+			} else {
+				sourceMapBuffer = readFileSync(
+					new URL(sourceMappingURL, filename)
+				);
+			}
+			if (sourceMapBuffer) {
+				const sourceMap: EncodedSourceMap = JSON.parse(
+					new TextDecoder().decode(sourceMapBuffer)
+				);
+				tracer = new TraceMap(sourceMap);
+			}
 		}
-		const sourceMap: EncodedSourceMap = JSON.parse(
-			new TextDecoder().decode(sourceMapBuffer)
-		);
-		tracer = new TraceMap(sourceMap);
+		sourceMapCache.set(filename, tracer);
 	}
-	sourceMapCache.set(filename, tracer);
 	return tracer;
 }