Can't find the name property inside the err object.

[saysonjerald]

It seems like Express removed the name property inside the err object. Can anyone confirm this?
This is how it looks like on my Postman

{
    "status": "error",
    "error": {
        "stringValue": "\"5f9618b492f2d81f5cb032829\"",
        "kind": "ObjectId",
        "value": "5f9618b492f2d81f5cb032829",
        "path": "_id",
        "reason": {},
        "statusCode": 500,
        "status": "error"
    },
    "message": "Cast to ObjectId failed for value \"5f9618b492f2d81f5cb032829\" at path \"_id\" for model \"Tour\"",
    "stack": "CastError: Cast to ObjectId failed for value \"5f9618b492f2d81f5cb032829\" at path \"_id\" for model \"Tour\"\n    at model.Query.exec (C:\\Users\\SayJee\\OneDrive\\Desktop\\Nodles\\complete-node-bootcamp-master\\4-natours\\practice\\node_modules\\mongoose\\lib\\query.js:4352:21)\n    at model.Query.Query.then (C:\\Users\\SayJee\\OneDrive\\Desktop\\Nodles\\complete-node-bootcamp-master\\4-natours\\practice\\node_modules\\mongoose\\lib\\query.js:4444:15)\n    at processTicksAndRejections (internal/process/task_queues.js:97:5)"
}

As you can see in the code above, there is no 'name' property,, therefore we can't use this code below anymore and it's outdated. if(error.name === 'CastError') error = handleCastErrorDB(error); i even tried to make a console.log(error.name) and you know what? it returns undefined.

Is there an alternative solution for this? Thanks for checking out.

[Yash1256]

Yup the same is happening with me... @saysonjerald. @jonasschmedtmann Can u please confirm this and update it in the video too..

[nvispute]

I think i understand what is happening here.. You See the functions in our ErrorController.js handleCastErrorDB() OR handleDuplicateFieldsDB() are thrown by Mongoose or MongoDB (Official Doc Link for Error's coming from mongoDB) and propbably it is MongoDb who must have stopped emitting error.name value and switched to StatusCodes instead as seen in the Official Doc Link. In our ErrorController.js we do have some errors checked by statuscode before we call the custom functions in the if loops such as this one if (error.code === 11000) error = handleDuplicateFieldsDB(error);

In Code shared by @saysonjerald you can see that we do have statuscode, Also in the "stack": you can see we have a string starting with "CastError" I think they must have done it to prevent information leakage while in prod mode as stack is mostly used during development and not during Prod.

Quick Fix can be to completly switch over to statusCodes Option 1 Inside our errorController.js, call the custom functions in the If statements with err.statusCode instead of err.name Option 2 (Long Way) We can Take the String inside of the stack and check for the string starting value with the previous names we already have defined in our if block

Or a combination of both...

[slymachenko]

I fixed it using the 2nd option suggested by @nvispute

I put this code after the error variable declaration: if (err.stack.indexOf('CastError', 0) === 0) error.name = 'CastError';

Hope it works for you

[amiraiman]

I think i understand what is happening here.. You See the functions in our ErrorController.js handleCastErrorDB() OR handleDuplicateFieldsDB() are thrown by Mongoose or MongoDB (Official Doc Link for Error's coming from mongoDB) and propbably it is MongoDb who must have stopped emitting error.name value and switched to StatusCodes instead as seen in the Official Doc Link. In our ErrorController.js we do have some errors checked by statuscode before we call the custom functions in the if loops such as this one if (error.code === 11000) error = handleDuplicateFieldsDB(error);

In Code shared by @saysonjerald you can see that we do have statuscode, Also in the "stack": you can see we have a string starting with "CastError" I think they must have done it to prevent information leakage while in prod mode as stack is mostly used during development and not during Prod.

Quick Fix can be to completly switch over to statusCodes Option 1 Inside our errorController.js, call the custom functions in the If statements with err.statusCode instead of err.name Option 2 (Long Way) We can Take the String inside of the stack and check for the string starting value with the previous names we already have defined in our if block

Or a combination of both...

I don't think they change the error object. The name property is still there. What actually happen is because we are simply shallow copying the err object using spread operator. The problem is that the name property is inside the prototype of the err object but copying with spread operator returns a new object that does not include the prototype of the object that it is copying. The solution is to use Object.create() instead of the spread operator

sources:

• https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error/name
• https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Spread_syntax#spread_in_object_literals

[pranjalg131]

Thanks for the solution, I was frustrated for an hour trying to think what was wrong, turns out this is one of those occasions where destructuring backfires.

[YTeyddie22]

@amiraiman. Thanks for the help.

[AbdourahamaneIssakaSani]

I think i understand what is happening here.. You See the functions in our ErrorController.js handleCastErrorDB() OR handleDuplicateFieldsDB() are thrown by Mongoose or MongoDB (Official Doc Link for Error's coming from mongoDB) and propbably it is MongoDb who must have stopped emitting error.name value and switched to StatusCodes instead as seen in the Official Doc Link. In our ErrorController.js we do have some errors checked by statuscode before we call the custom functions in the if loops such as this one if (error.code === 11000) error = handleDuplicateFieldsDB(error); In Code shared by @saysonjerald you can see that we do have statuscode, Also in the "stack": you can see we have a string starting with "CastError" I think they must have done it to prevent information leakage while in prod mode as stack is mostly used during development and not during Prod. Quick Fix can be to completly switch over to statusCodes Option 1 Inside our errorController.js, call the custom functions in the If statements with err.statusCode instead of err.name Option 2 (Long Way) We can Take the String inside of the stack and check for the string starting value with the previous names we already have defined in our if block Or a combination of both...

I don't think they change the error object. The name property is still there. What actually happen is because we are simply shallow copying the err object using spread operator. The problem is that the name property is inside the prototype of the err object but copying with spread operator returns a new object that does not include the prototype of the object that it is copying. The solution is to use Object.create() instead of the spread operator

sources:

• https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error/name
• https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Spread_syntax#spread_in_object_literals

Thanks @amiraiman. Your answer helped however I got an empty error object in case of a duplicated field in mongodb. And here what I tried:

let error = Object.create(err, Object.getOwnPropertyDescriptors(err));

This adds the rest of properties of err object, after those in the prototype.

Know more: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/getOwnPropertyDescriptors

[jonasschmedtmann]

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On January 2, 2023 at 7:07 PM UTC, Abissa @.***) wrote:

I think i understand what is happening here.. You See the functions in our ErrorController.js handleCastErrorDB() OR handleDuplicateFieldsDB() are thrown by Mongoose or MongoDB (Official Doc Link for Error's coming from mongoDBhttps://docs.atlas.mongodb.com/api#errors) and propbably it is MongoDb who must have stopped emitting error.name value and switched to StatusCodes instead as seen in the Official Doc Link. In our ErrorController.js we do have some errors checked by statuscode before we call the custom functions in the if loops such as this one if (error.code === 11000) error = handleDuplicateFieldsDB(error); In Code shared by @saysonjeraldhttps://github.com/saysonjerald you can see that we do have statuscode, Also in the "stack": you can see we have a string starting with "CastError" I think they must have done it to prevent information leakage while in prod mode as stack is mostly used during development and not during Prod. Quick Fix can be to completly switch over to statusCodes Option 1 Inside our errorController.js, call the custom functions in the If statements with err.statusCode instead of err.name Option 2 (Long Way) We can Take the String inside of the stack and check for the string starting value with the previous names we already have defined in our if block Or a combination of both...

I don't think they change the error object. The name property is still there. What actually happen is because we are simply shallow copying the err object using spread operator. The problem is that the name property is inside the prototype of the err object but copying with spread operator returns a new object that does not include the prototype of the object that it is copying. The solution is to use Object.create() instead of the spread operator

[err]https://user-images.githubusercontent.com/87350788/137608388-567ac56f-3aee-490d-ae1d-24c667608fc9.png

sources:

• https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error/name
• https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Spread_syntax#spread_in_object_literals

Thanks @amiraimanhttps://github.com/amiraiman. Your answer helped however I got an empty error object in case of a duplicated field in mongodb. And here what I tried:

let error = Object.create(err, Object.getOwnPropertyDescriptors(err));

This adds the rest of properties of err object, after those in the prototype.

— Reply to this email directly, view it on GitHubhttps://github.com/jonasschmedtmann/complete-node-bootcamp/issues/55#issuecomment-1369152829, or unsubscribehttps://github.com/notifications/unsubscribe-auth/AEO2BAQGAXTID4KE3N6SKPDWQMRO5ANCNFSM4TXCJPTA. You are receiving this because you were mentioned.Message ID: @.***>

[renato76]

Abissa, thank you, this finally solved it for me aftwe days of trying to debug this!

Just to clarify, using the suggested solution of : let error = Object.create(err)

This solved it!