function isElectron() {
    // Renderer process
    if (typeof window !== 'undefined' && typeof window.process === 'object' && window.process.type === 'renderer') {
        return true;
    }

    // Main process
    if (typeof process !== 'undefined' && typeof process.versions === 'object' && !!process.versions.electron) {
        return true;
    }

    // Detect the user agent when the `nodeIntegration` option is set to true
    if (typeof navigator === 'object' && typeof navigator.userAgent === 'string' && navigator.userAgent.indexOf('Electron') >= 0) {
        return true;
    }

    return false;
}

通过preload在window预注入一个检测变量

const { contextBridge: bridge } = require('electron');
bridge.exposeInMainWorld('checkElectron', {
  isInElectron: () => {
    if (isElectron()) {
      return true;
    }
    return false;
  }
});

渲染进程直接可通过判断 window.checkElectron.isInElectron()来确定当前执行环境是否是electron,如果没有checkElectron 那说明当前环境就是浏览器环境，变量没有被注入