npm运行开发和npm运行构建的不同svelte变量值

我正在用rollup.js开发一个苗条+顺风+PHP站点。根据运行的是

npm run dev

还是

npm run build

，如何在svelte源文件中设置变量？我希望不同的构建连接到不同的后端服务器

这是我的package.json，以防万一。我对这些工具都是新手，所以如果我误解太多，请容忍我并纠正我。在运行

npm run build

之后，我运行了一个脚本，将scp的构建文件夹保存到生产服务器

{
  "name": "my-app",
  "version": "1.0.0",
  "scripts": {
    "watch:tailwind": "postcss public/tailwind.css -o public/index.css -w",
    "build:tailwind": "NODE_ENV=production postcss public/tailwind.css -o public/index.css",
    "dev": "run-p autobuild watch:tailwind",
    "build": "npm run build:tailwind && rollup -c",
    "start": "sirv public --single --host",
    "start:dev": "sirv public --single --dev",
    "autobuild": "rollup -c -w"
  },
  "devDependencies": {
    "@rollup/plugin-commonjs": "^16.0.0",
    "@rollup/plugin-node-resolve": "^10.0.0",
    "autoprefixer": "^10.0.4",
    "d3-interpolate": "^2.0.1",
    "npm-run-all": "^4.1.5",
    "postcss": "^8.1.10",
    "postcss-cli": "^8.3.0",
    "postcss-nested": "^5.0.1",
    "postcss-reporter": "^7.0.2",
    "rollup": "^2.3.4",
    "rollup-plugin-css-only": "^3.0.0",
    "rollup-plugin-livereload": "^2.0.0",
    "rollup-plugin-svelte": "^7.0.0",
    "rollup-plugin-terser": "^7.0.0",
    "svelte": "^3.0.0",
    "svelte-dnd-action": "^0.6.22",
    "svelte-loading-spinners": "^0.1.1",
    "tailwindcss": "^2.0.1"
  },
  "dependencies": {
    "sirv-cli": "^1.0.0"
  }
}

您可以使用：

捆绑时替换文件中字符串的汇总插件

plugins: [
    replace({
      // alternatively, one could pass process.env.NODE_ENV or 'development` to stringify
      'process.env.NODE_ENV': JSON.stringify('production')
    })
  ]