CastError doesn't return the entire nested path

[mar-ors]

Prerequisites

• I have written a descriptive issue title

Mongoose version

8.0.0

Node.js version

20.9.0

MongoDB version

6.2.0

Operating system

None

Operating system version (i.e. 20.04, 11.3, 10)

No response

Issue

Hello,
I'm testing Mongoose error feedback. When testing a ValidationError, the response returns a nested path, which allows me to trace the field in error in my object that I passed in my query.
Example: 'accessories.0.additionals.0.k'.
It's very useful for browsing and finding fields in error.

However, when testing a CastError, the return sends me the error by browsing the object. This means I can't go back down into my object to find my error correctly.
Example: for arrays, the index isn't specified, so it's impossible to retrieve it.

Schema :

{
    id: Schema.Types.ObjectId,
    name: String,
    accessories: [
        {
            isEnabled: Boolean,
            additionals: [
                {
                    k: String,
                    v: Number,
                },
            ],
        }
    ],
    actions: [
        {
            type: String,
            isEnabled: Boolean,
            subActions: [
                {
                    type: String,
                    isEnabled: Boolean,
                }
            ],
        },
    ],
}

Example of a body sent :

{
    "id": "6499a3ff77eb47522397bbc1",
    "name": "Soldier",
    "accessories": [
        {
            "isEnabled": true,
            "additionals": [
                {
                    "k": ["helmet"], 	        // mock an error type here
                    "v": 1,
                },
                {
                    "k": "shoes",
                    "v": 2,
                },
            ],
        }
    ],
    "actions": [
        {
            "type": "move",
            "isEnabled": true,
            "subActions": [
                {
                    "type": "move right",
                    "isEnabled": true,
                }
            ],
        },
    ],
}

And the server returns this CastError :

CastError: Cast to embedded failed for value "{
   isEnabled: true,
   additionals: [
     { k: [Array], v: 1 },
     { k: 'shoes', v: 50 },
   ],
   _id: '654d005f44b6b34ae2e19c43'
 }" (type Object) at path "accessories" because of "CastError" {
     stringValue: '"{\n' +
       "  isEnabled: true,\n" +
       '  additionals: [\n' +
       "    { k: [Array], v: 1 },\n" +
       "    { k: 'shoes', v: 2 },\n" +
       '  ],\n' +
       "  _id: '654d005f44b6b34ae2e19c43'\n" +
       '}"',
   messageFormat: undefined,
   kind: 'embedded',
   value: {
       isEnabled: true,
       additionals: [ [Object], [Object] ],
       _id: '654d005f44b6b34ae2e19c43'
   },
   path: 'accessories', 
   reason: CastError: Cast to embedded failed for value "{
         k: [ 'helmet' ],
         v: 1,
         _id: '654d005f44b6b34ae2e19c44'
     }" (type Object) at path "additionals" because of "CastError" {
         stringValue: '"{\n' +
           "  k: [ 'helmet' ],\n" +
           "  v: 1,\n" +
           "  _id: '654d005f44b6b34ae2e19c44'\n" +
           '}"',
       messageFormat: undefined,
       kind: 'embedded',
       value: { k: [Array], v: [Object], _id: '654d005f44b6b34ae2e19c44' },
       path: 'additionals',
       reason: CastError: Cast to string failed for value "[ 'helmet' ]" (type Array) at path "k" {
            stringValue: `"[ 'helmet' ]"`,
            messageFormat: undefined,
            kind: 'string',
            value: [Array],
            path: 'k', 
            reason: null,
            valueType: 'Array'
          },
       valueType: 'Object'
     },
   valueType: 'Object'
 }

Example of a ValidationError :

ValidationError : 
Error: Validation failed: accessories.0.additionals.0.k: "helme" doesn't belong to the defined values. {
   errors: {
     'accessories.0.additionals.0.k': ValidatorError: "helme" doesn't belong to the defined values.) {
       properties: [Object],
       kind: 'enum',
       path: 'accessories.0.additionals.0.k',                         // expected path for CastError
       value: 'helme',
       reason: undefined,
       [Symbol(mongoose:validatorError)]: true
     }
   },
   _message: 'Validation failed'
 }

[IslandRhythms]

Am able to get pathing for the errors. Please modify script below to demonstrate your issue.

const mongoose = require('mongoose');

const testSchema = new mongoose.Schema({
  id: mongoose.Schema.Types.ObjectId,
  name: String,
  accessories: [
      {
          isEnabled: Boolean,
          additionals: [
              {
                  k: String,
                  v: Number,
              },
          ],
      }
  ],
  actions: [
      {
          type: String,
          isEnabled: Boolean,
          subActions: [
              {
                  type: String,
                  isEnabled: Boolean,
              }
          ],
      },
  ],
});

const Test = mongoose.model('Test', testSchema);

async function run() {
  await mongoose.connect('mongodb://localhost:27017');
  await mongoose.connection.dropDatabase();

  const obj = {
    // id: '123456789012',
    name: 'Soldier',
    accessories: [
      {
        isEnabled: true,
        additionals: [
          {
            k: ['helmet'],
            v: 1
          },
          {
            k: 'shoes',
            v: 2
          }
        ]
      }
    ],
    actions: [
      {
        type: 'move',
        isEnabled: true,
        subActions: [
          { type: 'move right',
            isEnabled: true
          }
        ]
      }
    ]
  }

  await Test.create(obj);
  console.log(await Test.findOne())
  console.log('done');
}

run();

[rommni]

Hello thanks to have experimented, the problem seems to only appear on CastError and I can't manage to produce a CastError on create, we only have ValidationError.
On update however I manage to get the CastError with incomplete path. You should see the error updating you code as following:

const mongoose = require('mongoose');

const testSchema = new mongoose.Schema({
  id: mongoose.Schema.Types.ObjectId,
  name: String,
  accessories: [
      {
          isEnabled: Boolean,
          additionals: [
              {
                  k: String,
                  v: Number,
              },
          ],
      }
  ],
  actions: [
      {
          type: {type:String },
          isEnabled: Boolean,
          subActions: [
              {
                  type: {type:String },
                  isEnabled: Boolean,
              }
          ],
      },
  ],
});

const Test = mongoose.model('Test', testSchema);

async function run() {
  await mongoose.connect('mongodb://localhost:27017');
  await mongoose.connection.dropDatabase();

  const obj = {
    // id: '123456789012',
    name: 'Soldier',
    accessories: [
      {
        isEnabled: true,
        additionals: [
          {
            k: 'test',
            v: 1
          },
          {
            k: 'shoes',
            v: 2
          }
        ]
      }
    ],
    actions: [
      {
        type: 'move',
        isEnabled: true,
        subActions: [
          { type: 'move right',
            isEnabled: true
          }
        ]
      }
    ]
  }

  let soldier = await Test.create(obj);
  await Test.findOneAndUpdate({_id : soldier._id}, {
    "$set": {
      "accessories.0.additionals.0.k": ['test']
    }
  })

  console.log('done');
}

run();

[IslandRhythms]

Not able to reproduce but from the error message you had copy-pasted it seems like an object was passed and that triggered the cast error as opposed to the array of strings.
Although reason is null in this cast error so that may be an issue.

CastError: Cast to string failed for value "[ 'test' ]" (type Array) at path "k"
    at SchemaString.cast (C:\Users\Drumm\Desktop\Work\debugging\JavaScript\node_modules\mongoose\lib\schema\string.js:606:11)
    at SchemaString.SchemaType.applySetters (C:\Users\Drumm\Desktop\Work\debugging\JavaScript\node_modules\mongoose\lib\schemaType.js:1219:12)
    at SchemaString.castForQuery (C:\Users\Drumm\Desktop\Work\debugging\JavaScript\node_modules\mongoose\lib\schema\string.js:690:15)
    at castUpdateVal (C:\Users\Drumm\Desktop\Work\debugging\JavaScript\node_modules\mongoose\lib\helpers\query\castUpdate.js:569:19)
    at walkUpdatePath (C:\Users\Drumm\Desktop\Work\debugging\JavaScript\node_modules\mongoose\lib\helpers\query\castUpdate.js:374:24)
    at castUpdate (C:\Users\Drumm\Desktop\Work\debugging\JavaScript\node_modules\mongoose\lib\helpers\query\castUpdate.js:107:7)
    at model.Query._castUpdate (C:\Users\Drumm\Desktop\Work\debugging\JavaScript\node_modules\mongoose\lib\query.js:4569:10)
    at model.Query._findOneAndUpdate (C:\Users\Drumm\Desktop\Work\debugging\JavaScript\node_modules\mongoose\lib\query.js:3260:23)
    at model.Query.exec (C:\Users\Drumm\Desktop\Work\debugging\JavaScript\node_modules\mongoose\lib\query.js:4290:80)
    at processTicksAndRejections (node:internal/process/task_queues:96:5) {
  stringValue: `"[ 'test' ]"`,
  messageFormat: undefined,
  kind: 'string',
  value: [ 'test' ],
  path: 'k',
  reason: null,
  valueType: 'Array'
}

[rommni]

Hello, thank you for your time.
I'm not sure to understand your asnwer, sorry. If the message you pasted is the error message you got, you have the problem we mentionned.
You can see that path value in your message is "k", while I think we want something like ValidationError which was something like "accessories.0.additionals.0.k"