在nodeJS中使用Jest和supertest进行测试时，随机出现“重复的内容长度”错误

Question

所以我正在对NodeJS上的Rest API项目进行一些单元测试。

我设置了8个测试，可以进行基本的Rest API调用，例如登录和注销用户。我一遍又一遍地运行测试，问题是有时测试通过没问题，但有时某些测试失败并显示以下错误Error: Error: Parse Error: Duplicate Content-Length我要添加2个屏幕截图，一个用于通过测试，另一个用于测试失败。这两个屏幕截图来自在完全相同的代码上运行的测试。我正在使用的代码也随附：

const request = require('supertest');

const userOneId = new mongoose.Types.ObjectId();
const userOne = {
  _id: userOneId,
  name: 'Fabian Santos',
  email: 'testuser@test.com',
  password: '123Data!',
  active: true,
};

const userTwoId = new mongoose.Types.ObjectId();
const userTwo = {
  _id: userTwoId,
  name: 'Wencel Santos',
  email: 'testuser2@test.com',
  password: '123Data!!',
  active: true,
  tokens: [
    {
      token: jwt.sign({ _id: userTwoId }, process.env.JWT_SECRET),
    },
    {
      token: jwt.sign({ _id: userTwoId }, process.env.JWT_SECRET + 'extra'),
    },
  ],
};

const userThreeId = new mongoose.Types.ObjectId();
const userThree = {
  _id: userThreeId,
  name: 'Fabian Santos',
  email: 'testuser3@test.com',
  password: '123Data!',
  active: false,
};

const setupDB = async () => {
  await User.deleteMany();
  await new User(userOne).save();
  await new User(userTwo).save();
  await new User(userThree).save();
};

beforeEach(setupDB);

test('Should create a new user', async () => {
  const response = await request(app)
    .post('/api/users')
    .send({
      name: 'Wencel Santos',
      email: 'wencelsantos@gmail.com',
      password: 'Mpasss123!',
    })
    .expect(201);
  // Assert user create din DB
  const user = await User.findById(response.body.user._id);
  expect(user).toBeTruthy();
  // Assert Expected object
  expect(response.body).toMatchObject({
    user: {
      active: false,
      name: 'Wencel Santos',
      email: 'wencelsantos@gmail.com',
    },
    token: user.activationToken,
  });
});

test('Should not create a new user with inapropiate password', async () => {
  await request(app)
    .post('/api/users')
    .send({
      name: 'Wencel Santos',
      email: 'wencelsantos@gmail.com',
      password: 'Mpasss123',
    })
    .expect(400);
});

test('Should not create a new user with existing email', async () => {
  await request(app)
    .post('/api/users')
    .send({
      name: 'Wencel Santos',
      email: userOne.email,
      password: 'Mpasss123',
    })
    .expect(400);
});

test('Should not create a new user with incomplete info', async () => {
  await request(app)
    .post('/api/users')
    .send({
      name: '',
      email: 'wencelsantos@gmail.com',
      password: 'Mpasss123!',
    })
    .expect(400);
  await request(app)
    .post('/api/users')
    .send({
      name: 'Wencel Santos',
      email: '',
      password: 'Mpasss123',
    })
    .expect(400);
  await request(app)
    .post('/api/users')
    .send({
      name: 'Wencel Santos',
      email: 'wencelsantos@gmail.com',
      password: '',
    })
    .expect(400);
});

test('Should login existing user', async () => {
  const response = await request(app)
    .post('/api/users/login')
    .send({
      email: userOne.email,
      password: userOne.password,
    })
    .expect(200);
  const user = await User.findById(userOne._id);
  // Assert Expected object

  expect(user.tokens[0]).toMatchObject({ token: response.body.token });
});

test('Should not login non existing user', async () => {
  await request(app)
    .post('/api/users/login')
    .send({
      email: 'wencelsantos@gmail.com',
      password: userOne.password,
    })
    .expect(400);
});

test('Should not login with wrong password or missing information', async () => {
  await request(app)
    .post('/api/users/login')
    .send({
      email: '',
      password: userOne.password,
    })
    .expect(400);
  await request(app)
    .post('/api/users/login')
    .send({
      email: userOne.password,
      password: 'aksdjfaksldjf',
    })
    .expect(400);
  await request(app)
    .post('/api/users/login')
    .send({
      email: userOne.password,
      password: '',
    })
    .expect(400);
});

test('Should not login inactive user', async () => {
  await request(app)
    .post('/api/users/login')
    .send({
      email: userThree.email,
      password: userThree.password,
    })
    .expect(400);
});

test('Should logout user', async () => {
  await request(app)
    .post('/api/users/logout')
    .set('Authorization', `Bearer ${userTwo.tokens[0].token}`)
    .send()
    .expect(200);
  const user = await User.findById(userTwo._id);
  expect(user.tokens).toHaveLength(1);
});

现在我添加到套件中的测试越多，发生此错误的可能性就越大。

值得注意的是，如果我分别运行每个测试，这意味着我注释掉了其他测试，它们总是会通过，只有当我取消对所有测试的注释并带内运行它们时才会出现错误。

我的Jest配置是这个jest --watch --runInBand