Node.js收到错误？无法改变为真

Question

我已经运行它并且它出现了错误错误，我该如何解决？我希望保持这个expect(bc.isValidChain(bc2.chain)).toBe(true);是真正的价值而不是虚假。

blockchain.test.js

const Blockchain = require('./blockchain');
const Block = require('./block');

describe('Blockchain', () => {
    let bc, bc2;

    beforeEach (() => {
        bc = new Blockchain();  
        bc2 = new Blockchain();
    });

    it('starts with genesis block', ()=> {
        expect(bc.chain[0]).toEqual(Block.genesis());
    });

    it('adds a new block', () => {
        const data = 'foo';
        bc.addBlock(data);

        expect(bc.chain[bc.chain.length-1].data).toEqual(data);
    });

    it('validates a valid chain', () => {
        bc2.addBlock('foo');

        expect(bc.isValidChain(bc2.chain)).toBe(true);
    });

    it('invalidates a chain with a corrupt genesis block', () => {
        bc2.chain[0].data = 'Bad data';

        expect(bc.isValidChain(bc2.chain)).toBe(false);
    });

    it('invalidates a corrupt chain', () => {
        bc2.addBlock('foo');
        bc2.chain[1].data = 'Not foo';

        expect(bc.isValidChain(bc2.chain)).toBe(false);
    });
});

git bamp run

 ● Blockchain › validates a valid chain

    expect(received).toBe(expected) // Object.is equality

    Expected value to be:
      true
    Received:
      false

      24 |              bc2.addBlock('foo');
      25 |
    > 26 |              expect(bc.isValidChain(bc2.chain)).toBe(true);
      27 |      });
      28 |
      29 |      it('invalidates a chain with a corrupt genesis block', () => {

      at Object.it (blockchain.test.js:26:38)

PASS .\block.test.js

Test Suites: 1 failed, 1 passed, 2 total
Tests:       1 failed, 6 passed, 7 total
Snapshots:   0 total
Time:        0.209s, estimated 1s
Ran all test suites.