node.js - 为什么 Mongoose 验证器不验证字段类型？

Question

我正在尝试验证 Mongoose 模式，但我无法理解类型验证的一件事。我将数字类型传递给字符串字段，并希望它在验证中失败，但它通过了。这是怎么发生的，谁能解释一下这背后的逻辑？
示例.js

const mongoose = require('mongoose');

async function validateSample(sample) {
  try {
    await sample.validate();
    return true;
  } catch (error) {
    return false;
  }
}

async function execMethod(){
  var userSchema = new mongoose.Schema({
    phone: {
      type: String,
      minlength: 2,
      maxlength: 4,
      validate: {
        validator: function(v) {
          return /^\d+$/.test(v);
        },
        message: `not a valid phone number!`
      },
      required: [true, 'User phone number required']
    }
  });
  
  var User = mongoose.model('user', userSchema);
  var validUser = new User({phone: '1234'});
  var invalidUser = new User({phone: 1235});
  const result = await validateSample(validUser);
  const result1 = await validateSample(invalidUser);
  console.log(result);  // true
  console.log(result1)  // expected false as number type is assigned to phone. But returns true, why?
}

execMethod()

Answer 1

那实际上是 a feature Mongoose 验证。

Before running validators, Mongoose attempts to coerce values to the correct type. This process is called casting the document. If casting fails for a given path, the error.errors object will contain a CastError object.

Casting runs before validation, and validation does not run if casting fails.

在这种情况下，一个数字 1235被转换为字符串 '1235' ，通过验证就好了。

现在，有 a FR open为 Mongoose 提供覆盖转换逻辑的能力(完全禁用它或自定义)，但它是开放的，未实现。

另一种方法是改变类型范围内的类型转换( allowed since 5.4 )，如下所示:

mongoose.Schema.Types.String.cast(false); // prevents all casts to string

...但它可能很麻烦，因为相同的规则适用于所有对象。