"scripts": {
    "start": "cross-env REACT_APP_SECRET_ENV=‘development‘ node scripts/start.js",   // 生成的项目文件本地运行的命令，这里加上测试打包环境
    "build": "node scripts/build.js",
    "test": "node scripts/test.js",
    "dev": "cross-env REACT_APP_SECRET_ENV=‘development‘ node scripts/build.js",   // development 测试环境
    "demo": "cross-env REACT_APP_SECRET_ENV=‘demoing‘ node scripts/build.js",     // demoing 演示环境
    "prod": "cross-env REACT_APP_SECRET_ENV=‘production‘ node scripts/build.js"   // production 正式环境
  },

function getClientEnvironment(publicUrl) {
  const raw = Object.keys(process.env)
    .filter(key => REACT_APP.test(key))
    .reduce(
      (env, key) => {
        env[key] = process.env[key];
        return env;
      },
      {
        // Useful for determining whether we’re running in production mode.
        // Most importantly, it switches React into the correct mode.
        NODE_ENV: process.env.NODE_ENV || ‘development‘,
+        REACT_APP_SECRET_ENV: process.env.REACT_APP_SECRET_ENV,   // 新加的环境变量------------------为了看起来明显点^_^
        // Useful for resolving the correct path to static assets in `public`.
        // For example, <img src={process.env.PUBLIC_URL + ‘/img/logo.png‘} />.
        // This should only be used as an escape hatch. Normally you would put
        // images into the `src` and `import` them in code to get their paths.
        PUBLIC_URL: publicUrl,
        // We support configuring the sockjs pathname during development.
        // These settings let a developer run multiple simultaneous projects.
        // They are used as the connection `hostname`, `pathname` and `port`
        // in webpackHotDevClient. They are used as the `sockHost`, `sockPath`
        // and `sockPort` options in webpack-dev-server.
        WDS_SOCKET_HOST: process.env.WDS_SOCKET_HOST,
        WDS_SOCKET_PATH: process.env.WDS_SOCKET_PATH,
        WDS_SOCKET_PORT: process.env.WDS_SOCKET_PORT,
      }
    );

// config after eject: we‘re in ./config/
module.exports = {
  dotenv: resolveApp(‘.env‘),
  appPath: resolveApp(‘.‘),
  appBuild: resolveApp(‘build‘),    //  就是这个了，把 `build` 替换成你设置的文件名，根据`process.env.REACT_APP_SECRET_ENV`设置。
  appPublic: resolveApp(‘public‘),
  appHtml: resolveApp(‘public/index.html‘),
  appIndexJs: resolveModule(resolveApp, ‘src/index‘),
  appPackageJson: resolveApp(‘package.json‘),
  appSrc: resolveApp(‘src‘),
  appTsConfig: resolveApp(‘tsconfig.json‘),
  appJsConfig: resolveApp(‘jsconfig.json‘),
  yarnLockFile: resolveApp(‘yarn.lock‘),
  testsSetup: resolveModule(resolveApp, ‘src/setupTests‘),
  proxySetup: resolveApp(‘src/setupProxy.js‘),
  appNodeModules: resolveApp(‘node_modules‘),
  publicUrlOrPath,
};

module.exports.moduleFileExtensions = moduleFileExtensions;