From cf8cbca94fe3698672c4bc931b2e9b47b04bf296 Mon Sep 17 00:00:00 2001
From: "James P." <jp@drvortex.dev>
Date: Sun, 19 May 2024 13:25:04 -0500
Subject: [PATCH] `_open`/`_openSync` correctly handle non-ENOENT errors
 `_open`/`_openSync` add the original stack trace on the second throw Fixed
 `configure` overwritting per-backend `disableAsyncCache`

---
 src/config.ts              |  2 +-
 src/emulation/promises.ts  | 37 +++++++++++++++++++++++-------------
 src/emulation/sync.ts      | 39 ++++++++++++++++++++++++--------------
 tests/port/channel.test.ts |  6 +++++-
 4 files changed, 55 insertions(+), 29 deletions(-)

diff --git a/src/config.ts b/src/config.ts
index 3c6505b30..653f41ab0 100644
--- a/src/config.ts
+++ b/src/config.ts
@@ -128,7 +128,7 @@ export async function configure(config: MountConfiguration<Backend> | Partial<Co
 		}
 
 		if (isBackendConfig(mountConfig)) {
-			mountConfig.disableAsyncCache = config.disableAsyncCache || false;
+			mountConfig.disableAsyncCache ??= config.disableAsyncCache || false;
 		}
 
 		config.mounts[point] = await resolveMountConfig(mountConfig);
diff --git a/src/emulation/promises.ts b/src/emulation/promises.ts
index e235ae164..a3b73a990 100644
--- a/src/emulation/promises.ts
+++ b/src/emulation/promises.ts
@@ -512,19 +512,30 @@ async function _open(path: fs.PathLike, _flag: fs.OpenMode, _mode: fs.Mode = 0o6
 			default:
 				throw new ErrnoError(Errno.EINVAL, 'Invalid file flag');
 		}
-	} catch (e) {
-		switch (pathNotExistsAction(flag)) {
-			case ActionType.CREATE:
-				// Ensure parent exists.
-				const parentStats: Stats = await fs.stat(dirname(resolved), cred);
-				if (parentStats && !parentStats.isDirectory()) {
-					throw ErrnoError.With('ENOTDIR', dirname(path), '_open');
-				}
-				return new FileHandle(await fs.createFile(resolved, flag, mode, cred));
-			case ActionType.THROW:
-				throw ErrnoError.With('ENOENT', path, '_open');
-			default:
-				throw new ErrnoError(Errno.EINVAL, 'Invalid file flag');
+	} catch (_) {
+		const original = _ as ErrnoError;
+		if(original.code != 'ENOENT') {
+			throw original;
+		}
+		try {
+			switch (pathNotExistsAction(flag)) {
+				case ActionType.CREATE:
+					// Ensure parent exists.
+					const parentStats: Stats = await fs.stat(dirname(resolved), cred);
+					if (parentStats && !parentStats.isDirectory()) {
+						throw ErrnoError.With('ENOTDIR', dirname(path), '_open');
+					}
+					return new FileHandle(await fs.createFile(resolved, flag, mode, cred));
+				case ActionType.THROW:
+					throw ErrnoError.With('ENOENT', path, '_open');
+				default:
+					throw new ErrnoError(Errno.EINVAL, 'Invalid file flag');
+			}
+		} catch (_) {
+			const ex = _ as ErrnoError;
+			ex.stack += '\n<original>\n';
+			ex.stack += (original as Error).stack;
+			throw ex;
 		}
 	}
 }
diff --git a/src/emulation/sync.ts b/src/emulation/sync.ts
index ca8984f15..c8cbc26b8 100644
--- a/src/emulation/sync.ts
+++ b/src/emulation/sync.ts
@@ -129,20 +129,31 @@ function _openSync(_path: fs.PathLike, _flag: fs.OpenMode, _mode?: fs.Mode | nul
 	let stats: Stats;
 	try {
 		stats = wrap('statSync', resolveSymlinks, path, cred);
-	} catch (e) {
-		// File does not exist.
-		switch (pathNotExistsAction(flag)) {
-			case ActionType.CREATE:
-				// Ensure parent exists.
-				const parentStats: Stats = wrap('statSync', resolveSymlinks, dirname(path), cred);
-				if (!parentStats.isDirectory()) {
-					throw ErrnoError.With('ENOTDIR', dirname(path), '_open');
-				}
-				return wrap('createFileSync', resolveSymlinks, path, flag, mode, cred);
-			case ActionType.THROW:
-				throw ErrnoError.With('ENOENT', path, '_open');
-			default:
-				throw new ErrnoError(Errno.EINVAL, 'Invalid FileFlag object.');
+	} catch (_) {
+		const original = _ as ErrnoError;
+		if(original.code != 'ENOENT') {
+			throw original;
+		}
+		try {
+			// File does not exist.
+			switch (pathNotExistsAction(flag)) {
+				case ActionType.CREATE:
+					// Ensure parent exists.
+					const parentStats: Stats = wrap('statSync', resolveSymlinks, dirname(path), cred);
+					if (!parentStats.isDirectory()) {
+						throw ErrnoError.With('ENOTDIR', dirname(path), '_open');
+					}
+					return wrap('createFileSync', resolveSymlinks, path, flag, mode, cred);
+				case ActionType.THROW:
+					throw ErrnoError.With('ENOENT', path, '_open');
+				default:
+					throw new ErrnoError(Errno.EINVAL, 'Invalid FileFlag object.');
+			}
+		} catch (_) {
+			const ex = _ as ErrnoError;
+			ex.stack += '\n<original>\n'
+			ex.stack += (original as Error).stack;
+			throw ex;
 		}
 	}
 	if (!stats.hasAccess(mode, cred)) {
diff --git a/tests/port/channel.test.ts b/tests/port/channel.test.ts
index c50f27855..faba52249 100644
--- a/tests/port/channel.test.ts
+++ b/tests/port/channel.test.ts
@@ -17,7 +17,7 @@ describe('FS with MessageChannel', () => {
 	test('configuration', async () => {
 		tmpfs = await resolveMountConfig({ backend: InMemory, name: 'tmp' });
 		attachFS(port2, tmpfs);
-		await configure({ backend: Port, port: port1 });
+		await configure({ backend: Port, port: port1, disableAsyncCache: true });
 	});
 
 	test('write', async () => {
@@ -33,4 +33,8 @@ describe('FS with MessageChannel', () => {
 	test('read', async () => {
 		expect(await fs.promises.readFile('/test', 'utf8')).toBe(content);
 	});
+
+	test('readFileSync should throw', () => {
+		expect(() => fs.readFileSync('/test', 'utf8')).toThrow('ENOTSUP');
+	});
 });