Function proxyPass

packages/cli/src/util/dev/server.ts:3158–3183

* Mimic nginx's `proxy_pass` for routes using a URL as `dest`.

(
  req: http.IncomingMessage,
  res: http.ServerResponse,
  dest: string,
  devServer: DevServer,
  requestId: string,
  ignorePath: boolean = true
)

 * Mimic nginx's `proxy_pass` for routes using a URL as `dest`.
 */
function proxyPass(
  req: http.IncomingMessage,
  res: http.ServerResponse,
  dest: string,
  devServer: DevServer,
  requestId: string,
  ignorePath: boolean = true
): void {
  devServer.proxy.web(
    req,
    res,
    { target: dest, ignorePath },
    (error: NodeJS.ErrnoException) => {
      // response transforms for this request would never be applied
      // so clear the stored transforms
      devServer.clearResponseTransforms(req);
      // only debug output this error because it's always something generic like
      // "Error: socket hang up"
      // and the original error should have already been logged
      output.debug(`Failed to complete request to ${req.url}: ${error}`);
      if (!res.headersSent) {
        devServer.sendError(req, res, requestId, 'FUNCTION_INVOCATION_FAILED');
      }
    }
  );
}

/**
 * Handle requests for static files with serve-handler.