TypeScript SDK API improvements

sdk/typescript/src/errors.ts

@@ -0,0 +1,53 @@
+/**
+ * POSIX-style error codes for filesystem operations.
+ */
+export type FsErrorCode =
+  | 'ENOENT'    // No such file or directory
+  | 'EEXIST'    // File already exists
+  | 'EISDIR'    // Is a directory (when file expected)
+  | 'ENOTDIR'   // Not a directory (when directory expected)
+  | 'ENOTEMPTY' // Directory not empty
+  | 'EPERM'     // Operation not permitted
+  | 'EINVAL'    // Invalid argument
+  | 'ENOSYS';   // Function not implemented (use for symlinks)
+
+/**
+ * Filesystem syscall names for error reporting.
+ * rm, scandir and copyFile are not actual syscall but used for convenience
+ */
+export type FsSyscall =
+  | 'open'
+  | 'stat'
+  | 'mkdir'
+  | 'rmdir'
+  | 'rm'
+  | 'unlink'
+  | 'rename'
+  | 'scandir'
+  | 'copyfile'
+  | 'access';
+
+export interface ErrnoException extends Error {
+  code?: FsErrorCode;
+  syscall?: FsSyscall;
+  path?: string;
+}
+
+export function createFsError(params: {
+  code: FsErrorCode;
+  syscall: FsSyscall;
+  path?: string;
+  message?: string;
+}): ErrnoException {
+  const { code, syscall, path, message } = params;
+  const base = message ?? code;
+  const suffix =
+    path !== undefined
+      ? ` '${path}'`
+      : '';
+  const err = new Error(`${code}: ${base}, ${syscall}${suffix}`) as ErrnoException;
+  err.code = code;
+  err.syscall = syscall;
+  if (path !== undefined) err.path = path;
+  return err;
+}