Go How do you deserialize a JSON array of mixed types

Issue

I’m writing a go client for aigaming.com, and when I make an invalid request the response will include some error information. I want to capture this response with a struct, however, I run into trouble when the types begin to mix.

The JSON structure of the error data looks like this:

{  
   "errorMessage":"An error occurred (ValidationException) when calling the Query operation: ExpressionAttributeValues contains invalid value: One or more parameter values were invalid: An AttributeValue may not contain an empty string for key :v0",
   "errorType":"ClientError",
   "stackTrace":[  
      [  
         "/var/task/OfferGame.py",
         612,
         "lambda_handler",
         "game = offerGame.createOffer()"
      ],
      [  
         "/var/task/OfferGame.py",
         586,
         "createOffer",
         "gameRow = self.findSuitableWaitingGame()"
      ],
      [  
         "/var/task/OfferGame.py",
         503,
         "findSuitableWaitingGame",
         "Key('GameStyleId_GameStatus').eq(str(self.gameStyleId) + '_' + self.Game.KEY_GAME_STATUS_WAITING)"
      ]
      // There are more items, but I'll omit them for brevity
   ]
}

This is mostly trivial to capture, however, the trouble comes with the stackTrace items. It is an array, of arrays, of mixed types.

The best results I’ve had so far are with this struct. It doesn’t actually give me any data (all the elements are empty), but it comes back with the correct number of elements and nested elements to have.

type ErrorResponse struct {
    ErrorMessage string          `json:"errorMessage"`
    ErrorType    string          `json:"errorType"`
    StackTrace   [][]interface{} `json:"stackTrace"`
}

Is there a way to parse these items of mixed type? Can I possibly work around this by somehow forcing all the integer elements to be treated as strings instead?

UPDATE:
Here is what I mean by “empty”. The correct number of things are there, but they do not appear to be initialized.
enter image description here

Solution

You’re on the right track, just continue. Whenever you need something from StackTrace, use type assertions and execute code according to the actual type. Do note that type assertions return 2 values, check the second one to see whether the assumed type is correct or not.

Answered By – LeleDumbo

Answer Checked By – Timothy Miller (GoLangFix Admin)

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