測試合約時，NodeJS 返回：“SyntaxError: Unexpected token u in JSON at position 0”

我的 NodeJS 腳本給了我這個錯誤：

1)"before each" hook for "deploy a factory and a lottery"
SyntaxError: Unexpected token u in JSON at position 0
at JSON.parse((anonymous))
at Context.(anonymous) (test/lottery/test.js:18:46)
at processTicksAndRejections(internal/process/task_queues.js:94:5)

文件 test.js

const assert = require('assert');
const ganache = require('ganache-cli');
const Web3 = require('web3');
const web3 = new Web3(ganache.provider());

const compiledFactory = require('../ethereum/build/LotteriaFactory.json');
const compiledLotteria = require('../ethereum/build/Lotteria.json');
//two istances of the contract inside the build dir

let accounts;
let factory;
let lotteriaAddress;
let lotteria;

beforeEach(async () => {
 accounts = await web3.eth.getAccounts();

 factory = await new web3.eth.Contract(JSON.parse(compiledFactory.interface))
 .deploy({ data: compiledFactory.bytecode })
 .send({ from: accounts[0], gas: '1000000' });

 await factory.methods.createNew('5').send({
   from: accounts[0], //manager
   gas: '1000000'
 });

 const addresses = await factory.methods.active().call();
 lotteriaAddress = addresses[0]; //[LotteriaFactory]

  lotteria = new web3.eth.Contract(
    JSON.parse(compiledLotteria.interface),
    lotteriaAddress
  );
});

describe('Lottery', () => {
 it('deploy a factory and a lottery', () => {
   assert.ok(factory.options.address);
   assert.ok(lotteria.options.address);
 });
});

我的依賴是：

• 溶膠 0.5.0
• 網路3 1.2.6

有人能幫我嗎？我錯過了什麼？

您的問題是嘗試JSON.parse(compiledFactory.interface).

函式JSON.parse需要一個表示有效 JSON 對象的輸入字元串。

您正在嘗試通過需要JSON 文件來獲取該對象：

const compiledFactory = require('../ethereum/build/LotteriaFactory.json');

但是require語句被指定用於導入 JS 程式碼，而不是 JSON 對象！

不需要這個文件，你應該簡單地閱讀它：

const fs = require('fs');
const compiledFactory = fs.readFileSync('../ethereum/build/LotteriaFactory.json', {encoding: "utf8"});

最後，為了訪問該interface對象的欄位，請更改：

JSON.parse(compiledFactory.interface)

對此：

JSON.parse(compiledFactory).interface

引用自：https://ethereum.stackexchange.com/questions/80654