Function resolveProjectFile

src/ui-server/security.ts:274–298

(projectRoot: string, relativePath: string)

 *   the path escapes the root by traversal or symlink.
 */
export function resolveProjectFile(projectRoot: string, relativePath: string): string {
  if (typeof relativePath !== 'string' || relativePath.trim() === '') {
    throw new PathRefusalError('No file path was given.');
  }
  const decoded = decodePath(relativePath);
  if (decoded === null) {
    throw new PathRefusalError(`Refusing to read an unusable path: ${relativePath}`);
  }

  // Sensitive-directory refusal, same list the MCP entry points use. Checked on
  // the ROOT rather than the leaf: a root of `/etc` makes every path under it
  // sensitive, and a leaf check would have to enumerate the world.
  const rootError = validateProjectPath(projectRoot);
  if (rootError) throw new PathRefusalError(rootError);

  if (path.isAbsolute(decoded)) {
    throw new PathRefusalError(`Refusing to read an absolute path: ${decoded}`);
  }

  const absolute = validatePathWithinRoot(projectRoot, decoded);
  if (!absolute) {
    throw new PathRefusalError(`Refusing to read a path outside the project: ${decoded}`);
  }
  return absolute;
}