Function getFirstHeaderValue

src/node/orpc/server.ts:180–193

(
  req: Pick<http.IncomingMessage, "headers">,
  headerName: string
)

};

function getFirstHeaderValue(
  req: Pick<http.IncomingMessage, "headers">,
  headerName: string
): string | null {
  const rawValue = req.headers[headerName.toLowerCase()];
  const value = Array.isArray(rawValue) ? rawValue[0] : rawValue;

  if (typeof value !== "string") {
    return null;
  }

  const firstValue = value.split(",")[0]?.trim();
  return firstValue?.length ? firstValue : null;
}

function normalizeProtocol(rawProtocol: string): "http" | "https" | null {
  const normalized = rawProtocol.trim().toLowerCase().replace(/:$/, "");