无法在生产模式下启动 sapper 应用程序

Question

正如标题所说，我无法在生产模式下启动我的工兵项目。当我运行npm run start 时，我会在控制台上得到这个输出：

niklas@Niklass-iMac project-name % npm run start

> apple-on-svelte@0.0.1 start /Users/niklas/path/to/project
> node __sapper__/build

Starting server on port 3000
niklas@Niklass-iMac project-name %

如您所见，命令立即中止，服务器未启动。可能是什么原因？

我的package.json 看起来像这样

{
    "name": "project name",
    "description": "description",
    "version": "0.0.1",
    "scripts": {
        "build": "sapper build --legacy",
        "deploy": "firebase deploy --only functions",
        "dev": "sapper dev",
        "export": "sapper export --legacy",
        "fb_start": "npm run shell",
        "logs": "firebase functions:log",
        "serve": "firebase emulators:start --only functions",
        "shell": "firebase functions:shell",
        "start": "node __sapper__/build"
    },
    "browserslist": [
        "last 3 version"
    ],
    "engines": {
        "node": "10"
    },
    "dependencies": {
        "compression": "^1.7.4",
        "express": "^4.17.1",
        "firebase-admin": "^8.10.0",
        "firebase-functions": "^3.6.0",
        "sirv": "^0.4.2"
    },
    "devDependencies": {
        "@babel/core": "^7.9.0",
        "@babel/plugin-syntax-dynamic-import": "^7.8.3",
        "@babel/plugin-transform-runtime": "^7.9.0",
        "@babel/preset-env": "^7.9.5",
        "@babel/runtime": "^7.9.2",
        "@fullhuman/postcss-purgecss": "^2.1.2",
        "@rollup/plugin-commonjs": "11.0.2",
        "@rollup/plugin-node-resolve": "^7.1.3",
        "@rollup/plugin-replace": "^2.3.1",
        "autoprefixer": "^9.7.6",
        "cssnano": "^4.1.10",
        "firebase-functions-test": "^0.2.0",
        "npm-run-all": "^4.1.5",
        "postcss": "^7.0.27",
        "postcss-import": "^12.0.1",
        "postcss-nested": "^4.2.1",
        "postcss-url": "^8.0.0",
        "rollup": "^2.6.1",
        "rollup-plugin-babel": "^4.4.0",
        "rollup-plugin-postcss": "^2.6.1",
        "rollup-plugin-svelte": "^5.2.1",
        "rollup-plugin-terser": "^5.3.0",
        "sapper": "^0.27.12",
        "svelte": "^3.20.1",
        "svelte-preprocess": "^3.7.1",
        "svelte-preprocess-postcss": "^1.1.1",
        "tailwindcss": "^1.2.0"
    }
}

而我的src/server.js 看起来像这样：

import sirv from "sirv";
import express from "express";
import compression from "compression";
import * as sapper from "@sapper/server";

import "./assets/global.css";

const { PORT, NODE_ENV } = process.env;
const dev = NODE_ENV === "development";

const expressServer = express().use(
    compression({ threshold: 0 }),
    sirv("static", { dev }),
    sapper.middleware()
);

if (dev) {
    expressServer.listen(PORT, (err) => {
        if (err) console.log("error", err);
    });
}

export { expressServer };

而我的index.js 看起来像这样：

const functions = require("firebase-functions");
const { expressServer } = require("./__sapper__/build/server/server");

exports.ssr = functions.https.onRequest(expressServer);

我在 macOS 10.15.5 上使用汇总和最新的节点 lts 版本 没有问题，我可以运行npm run dev 或npm run build，但不能运行npm run start

我该如何解决这个问题？有什么想法吗？

Answer 1

据我判断您的快递服务，当not 处于开发模式时，您似乎没有收听传入的连接。对此负责的确切代码是：

// only in dev mode you listen to inc connections
if (dev) { 
    expressServer.listen(PORT, (err) => {
        if (err) console.log("error", err);
    });
}

当您不处于开发模式时，这将跳过列表部分。 我会考虑将 if 语句移到您的监听回调函数中，例如：

expressServer.listen(PORT, (err) => {
    if (err && dev) console.log("error", err);
});

这应该保持服务器运行并列出未来的连接。如果这对你有帮助，请给我一个小拇指。有关更多信息，我还向您推荐expressJS 的快速入门指南