我试图创建一个方法到userSchema，但我得到这个错误：
TypeError：无法将属性“generateAuthToken”设置为未定义

userSchema.methods.generateAuthToken = function() {
  // const token = jwt.sign({ _id: user._id }, config.get("JWTPRIVATEKEY"));
  const token = jwt.sign({ _id: this._id }, "Privatekey");
  return token;
};

字符串

注意：我没有使用箭头函数，而是使用普通函数：

var userSchema = {
  name: {
    type: String,
    require: true
  },
  email: {
    type: String,
    require: true,
    unique: true
  },
  password: {
    type: String
  }
};

userSchema.methods.generateAuthToken = function() {
  // const token = jwt.sign({ _id: user._id }, config.get("JWTPRIVATEKEY"));
  const token = jwt.sign({ _id: this._id }, "Privatekey");
  return token;
};

const User = mongoose.model("Users", new mongoose.Schema(userSchema));

function validateUser(user) {
  let schema = {
    name: Joi.string().required(),
    email: Joi.string()
      .required()
      .email(),
    password: Joi.string().required()
  };

  return Joi.validate(user, schema);
}

exports.User = User;
exports.validateUser = validateUser;

型

用例

let user = await User.findOne({ email: req.body.email });

  const token = user.generateAuthToken();

型