Webpack生产包错误，开发包工作精细。

Question

在开发节点api时，我在与webpack构建产品包时遇到了一个问题。在webpack配置中，如果模式被设置为“发展”，那么一切都很好。如果将模式设置为“production”，则运行节点bundle.js会给我带来错误，这说明不了多少。什么是问题，或者我应该如何调试它。

Error
    at c.<anonymous> (/Users/sten/Sites/Projects/Farmi/API/New/dist/bundle.js:2:747025)
    at c.<anonymous> (/Users/sten/Sites/Projects/Farmi/API/New/dist/bundle.js:2:217821)
    at c._callback (/Users/sten/Sites/Projects/Farmi/API/New/dist/bundle.js:2:217609)
    at c.l.end (/Users/sten/Sites/Projects/Farmi/API/New/dist/bundle.js:2:434863)
    at /Users/sten/Sites/Projects/Farmi/API/New/dist/bundle.js:2:255978
    at Array.forEach (<anonymous>)
    at /Users/sten/Sites/Projects/Farmi/API/New/dist/bundle.js:2:255955
    at processTicksAndRejections (node:internal/process/task_queues:78:11)

我的webpack制作配置：

const path = require('path');

module.exports = {
  mode: 'production',
  target: 'node',
  entry: './src/index.js',
  module: {
    rules: [
      {
        test: /\.(js|jsx)$/,
        exclude: /node_modules/,
        use: 'babel-loader',
      },
    ],
  },
  output: {
    path: path.resolve(__dirname, 'dist/'),
    filename: 'bundle.js',
  },
};

package.json：

{
  "name": "API",
  "version": "1.0.0",
  "description": "API",
  "main": "index.js",
  "author": "API",
  "license": "MIT",
  "dependencies": {
    "@koa/router": "^10.1.1",
    "axios": "^0.27.2",
    "file-extension": "^4.0.5",
    "get-4byte-chars": "^0.1.0",
    "koa": "^2.13.4",
    "lodash": "^4.17.21",
    "mime-types": "^2.1.35",
    "mysql": "^2.18.1",
    "pm3": "^0.0.0",
    "unique-filename": "^1.1.1",
    "winston": "^3.7.2"
  },
  "devDependencies": {
    "@babel/core": "^7.17.9",
    "@babel/plugin-transform-runtime": "^7.17.10",
    "@babel/preset-env": "^7.16.11",
    "babel-loader": "^8.2.5",
    "nodemon-webpack-plugin": "^4.7.1",
    "webpack": "^5.72.1",
    "webpack-cli": "^4.9.2"
  },
  "scripts": {
    "dev": "webpack --config=webpack.config.dev.js --watch",
    "build": "webpack --config=webpack.config.prod.js",
    "start": "node ./dist/bundle.js"
  }
}

Answer 1

通过消除代码块发现问题。看来webpack在缩小目标时打破了Node的MySQL包。

这里有一个参考资料：

https://github.com/serverless/serverless/issues/5946

移除建议的缩小，它可以工作。

要从mysql获得错误消息，我必须将代码包装到try / catch块中，即使我拒绝错误的承诺，也应该被调用函数_dbQuery的try / catch块捕获.还是不？

原文：

const _dbQuery = async (queryString, values = null) => {
  return new Promise((resolve, reject) => {
    const connection = mysql.createConnection({
      ...configuration.mysql,
    });

    connection.connect((err) => {
      if (err) reject(new Error(err.sqlMessage));
    });

    if (values !== null) {
      connection.query(queryString, values, (err, res, fields) => {
        if (err) reject(new Error(err.sqlMessage));
        resolve(res);
        connection.end();
      });
    } else {
      connection.query(queryString, (err, res, fields) => {
        if (err) reject(err.sqlMessage);
        resolve(res);
        connection.end();
      });
    }
  })
};

修改后给出了错误PROTOCOL_INCORRECT_PACKET_SEQUENCE：

const _dbQuery = async (queryString, values = null) => {
  return new Promise((resolve, reject) => {
    try {
      const connection = mysql.createConnection({
        ...configuration.mysql,
      });

      connection.connect((err) => {
        if (err) reject(new Error(err.sqlMessage));
      });

      if (values !== null) {
        connection.query(queryString, values, (err, res, fields) => {
          if (err) reject(new Error(err.sqlMessage));
          resolve(res);
          connection.end();
        });
      } else {
        connection.query(queryString, (err, res, fields) => {
          if (err) reject(new Error(err.sqlMessage));
          resolve(res);
          connection.end();
        });
      }
    } catch (err) {
      throw err;
    }
  });
};