Function getFirstHeader

src/node/http.ts:334–337

(req: http.IncomingMessage, headerName: string)

}

function getFirstHeader(req: http.IncomingMessage, headerName: string): string | undefined {
  const val = req.headers[headerName]
  return Array.isArray(val) ? val[0] : val
}

/**
 * Throw a forbidden error if origin checks fail. Call `next` if provided.