TypeError：无法读取未定义的属性“ _alreadyWrapped”

Question

我创建了一个集成了松露和React框架的项目，然后在truffle-config.js中配置了以太坊的rinkeby测试网络。但是，当我将合同迁移到rinkeby网络时，出现了问题。

truffle compile    
truffle migrate  --network rinkeby

然后出现一些错误

TypeError: Cannot read property '_alreadyWrapped' of undefined
    at Object.wrap (C:\Users\Lsy\AppData\Roaming\npm\node_modules\truffle\build\webpack:\packages\provider\wrapper.js:13:1)
    at Object.wrap (C:\Users\Lsy\AppData\Roaming\npm\node_modules\truffle\build\webpack:\packages\provider\index.js:9:1)
    at Object.create (C:\Users\Lsy\AppData\Roaming\npm\node_modules\truffle\build\webpack:\packages\provider\index.js:14:1)
    at TruffleConfig.get [as provider] (C:\Users\Lsy\AppData\Roaming\npm\node_modules\truffle\build\webpack:\packages\config\dist\configDefa
ults.js:189:1)
    at Object.detect (C:\Users\Lsy\AppData\Roaming\npm\node_modules\truffle\build\webpack:\packages\environment\environment.js:19:1)
    at C:\Users\Lsy\AppData\Roaming\npm\node_modules\truffle\build\webpack:\packages\core\lib\commands\migrate.js:192:1
Truffle v5.1.1 (core: 5.1.1)
Node v12.13.0

项目目录如下所示：

truffle-config.js

 const path = require("path");
    const HDWalletProvider = require('@truffle/hdwallet-provider');
    const fs = require('fs')  

    let secrets;
    console.log(path.join(__dirname, "secrets.json"));

    if (fs.existsSync(path.join(__dirname, "secrets.json"))){
      secrets = JSON.parse(fs.readFileSync(path.join(__dirname, "secrets.json"),'utf8'));
    }else{
      console.log("secrets.json doesn't exist!")
    }

    module.exports = {
      contracts_build_directory: path.join(__dirname, "client/src/contracts"),
      networks: {
        ganache:{
          host:"127.0.0.1",
          port:7545,
          network_id:"*"
        },
        develop: {
          port: 8545
        },
        rinkeby:{
          provider:()=>{
            new HDWalletProvider(secrets.mnemonic,"https://rinkeby.infura.io/v3/"+secrets.infuraProjectId);
          },
          network_id: '4'
        }
      }
    };

这个问题困扰了我很长时间，谁能帮助我！真的谢谢！

Answer 1

您忘记了return语句：

rinkeby: {
  provider: () => {
    return new HDWalletProvider(secrets.mnemonic,"https://rinkeby.infura.io/v3/"+secrets.infuraProjectId);
  },
  network_id: 4
}