zulip-desktop/app/main/proxy-util.ts

import * as ConfigUtil from "../common/config-util";

export interface ProxyRule {
  hostname?: string;
  port?: number;
}

// TODO: Refactor to async function
export async function resolveSystemProxy(
  mainWindow: Electron.BrowserWindow,
): Promise<void> {
  const page = mainWindow.webContents;
  const ses = page.session;
  const resolveProxyUrl = "www.example.com";

  // Check HTTP Proxy
  const httpProxy = (async () => {
    const proxy = await ses.resolveProxy("http://" + resolveProxyUrl);
    let httpString = "";
    if (
      proxy !== "DIRECT" &&
      (proxy.includes("PROXY") || proxy.includes("HTTPS"))
    ) {
      // In case of proxy HTTPS url:port, windows gives first word as HTTPS while linux gives PROXY
      // for all other HTTP or direct url:port both uses PROXY
      httpString = "http=" + proxy.split("PROXY")[1] + ";";
    }

    return httpString;
  })();
  // Check HTTPS Proxy
  const httpsProxy = (async () => {
    const proxy = await ses.resolveProxy("https://" + resolveProxyUrl);
    let httpsString = "";
    if (
      (proxy !== "DIRECT" || proxy.includes("HTTPS")) &&
      (proxy.includes("PROXY") || proxy.includes("HTTPS"))
    ) {
      // In case of proxy HTTPS url:port, windows gives first word as HTTPS while linux gives PROXY
      // for all other HTTP or direct url:port both uses PROXY
      httpsString += "https=" + proxy.split("PROXY")[1] + ";";
    }

    return httpsString;
  })();

  // Check FTP Proxy
  const ftpProxy = (async () => {
    const proxy = await ses.resolveProxy("ftp://" + resolveProxyUrl);
    let ftpString = "";
    if (proxy !== "DIRECT" && proxy.includes("PROXY")) {
      ftpString += "ftp=" + proxy.split("PROXY")[1] + ";";
    }

    return ftpString;
  })();

  // Check SOCKS Proxy
  const socksProxy = (async () => {
    const proxy = await ses.resolveProxy("socks4://" + resolveProxyUrl);
    let socksString = "";
    if (proxy !== "DIRECT") {
      if (proxy.includes("SOCKS5")) {
        socksString += "socks=" + proxy.split("SOCKS5")[1] + ";";
      } else if (proxy.includes("SOCKS4")) {
        socksString += "socks=" + proxy.split("SOCKS4")[1] + ";";
      } else if (proxy.includes("PROXY")) {
        socksString += "socks=" + proxy.split("PROXY")[1] + ";";
      }
    }

    return socksString;
  })();

  const values = await Promise.all([
    httpProxy,
    httpsProxy,
    ftpProxy,
    socksProxy,
  ]);
  const proxyString = values.join("");
  ConfigUtil.setConfigItem("systemProxyRules", proxyString);
  const useSystemProxy = ConfigUtil.getConfigItem("useSystemProxy", false);
  if (useSystemProxy) {
    ConfigUtil.setConfigItem("proxyRules", proxyString);
  }
}