export function initializeNetworkAgent()

in src/desktop/fetch.ts [23:79]
35 lines of code
9 McCabe index (conditional complexity)

export function initializeNetworkAgent(): void {
  const customAgent = ({ protocol }: Pick<URL, 'protocol'>): http.Agent => {
    if (protocol === 'http:') {
      return httpAgent;
    }
    return httpsAgent;
  };
  updateUserProxyUrl();
  /**
   * This works around an issue in the default VS Code proxy agent code. When `http.proxySupport`
   * is set to its default value and no proxy setting is being used, the proxy library does not
   * properly reuse the agent set on the http(s) method and is instead always using a new agent
   * per request.
   *
   * To work around this, we patch the default proxy agent method and overwrite the
   * `originalAgent` value before invoking it for requests that want to keep their connection
   * alive only when user is not using their own http proxy and the request contains keepAliveHeader
   *
   * c.f. https://github.com/microsoft/vscode/issues/173861
   * code reference: https://github.com/sourcegraph/cody/pull/868/files
   */
  try {
    const PacProxyAgent =
      // eslint-disable-next-line @typescript-eslint/no-explicit-any
      (globalThis as any)?.[nodeModules]?.[proxyAgentPath]?.[proxyAgent] ?? undefined;
    if (PacProxyAgent) {
      const originalConnect = PacProxyAgent.prototype.connect;
      // Patches the implementation defined here:
      // https://github.com/microsoft/vscode-proxy-agent/blob/d340b9d34684da494d6ebde3bcd18490a8bbd071/src/agent.ts#L53
      PacProxyAgent.prototype.connect = function (
        req: http.ClientRequest,
        opts: { protocol: string },
        // eslint-disable-next-line @typescript-eslint/no-explicit-any
      ): any {
        try {
          const connectionHeader = req.getHeader('connection');
          const connectionHeaderHasKeepAlive =
            connectionHeader === keepAliveHeader ||
            (Array.isArray(connectionHeader) && connectionHeader.includes(keepAliveHeader));

          if (connectionHeaderHasKeepAlive && userProxyUrl === '') {
            this.opts.originalAgent = customAgent(opts);
            return originalConnect.call(this, req, opts);
          }
          return originalConnect.call(this, req, opts);
        } catch {
          return originalConnect.call(this, req, opts);
        }
      };
    } else {
      log.info('PacProxyAgent not found');
    }
  } catch (error) {
    // Log any errors in the patching logic
    log.error('Failed to patch http agent', error);
  }
}