Function resolveWorkspaceFilePath

src/node/services/fileAtMentions.ts:27–56

(
  runtime: Runtime,
  workspacePath: string,
  filePath: string
)

}

function resolveWorkspaceFilePath(
  runtime: Runtime,
  workspacePath: string,
  filePath: string
): string {
  assert(filePath, "filePath is required");

  // Disallow absolute and home-relative paths.
  if (isAbsolutePathAny(filePath) || filePath.startsWith("~")) {
    throw new Error(`Invalid file path in @mention (must be workspace-relative): ${filePath}`);
  }

  // SSH uses POSIX paths; local runtime can use the platform resolver.
  const pathModule = runtime instanceof SSHRuntime ? path.posix : path;
  const cleaned = runtime instanceof SSHRuntime ? filePath.replace(/\\/g, "/") : filePath;

  const resolved = pathModule.resolve(workspacePath, cleaned);
  const relative = pathModule.relative(workspacePath, resolved);

  // Note: relative === "" means "same directory" (the workspace root itself).
  if (relative === "" || relative === ".") {
    throw new Error(`Invalid file path in @mention (expected a file, got directory): ${filePath}`);
  }

  if (relative.startsWith("..") || pathModule.isAbsolute(relative)) {
    throw new Error(`Invalid file path in @mention (path traversal): ${filePath}`);
  }

  return resolved;
}

function guessCodeFenceLanguage(filePath: string): string {
  const ext = path.extname(filePath).toLowerCase();