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The right way to know which line of json is failing to unmarshal? – Getting Assist

I’m engaged on an app that makes use of go to parse a json file for settings. I get the error proven under, nevertheless it’s not telling me what line within the json file is inflicting the problem. How do I see this?

panic: json: can't unmarshal string into Go worth of kind map[string]*json.RawMessage

You may verify your Go code to see the place you might have a area of kind map[string]*json.RawMessage after which verify your JSON file to see if it’s a string as an alternative.

I don’t have entry to the code. I hoped there was a strategy to activate extra detailed logs like in Rust

I’m not conscious of any approach to try this in Go.

May you paste your JSON into a web-based JSON parser and see what the offending line is that approach? Additionally you might organize a fast check utilizing the playground and attempt to debug it that approach. For instance, modify this playground hyperlink to have your precise JSON:

func primary() {
	// Substitute this along with your JSON
	byt := []byte(`{ "value1": "check", "value2": }`)
	var dat map[string]*json.RawMessage
	if err := json.Unmarshal(byt, &dat); err != nil {

The output from that’s at the least extra descriptive than what your executable is providing you with:

panic: invalid character '}' on the lookout for starting of worth

goroutine 1 [running]:
	/tmp/sandbox266866198/prog.go:13 +0xe7

Program exited.

You may additionally strive the process outlined right here together with that go playground hyperlink to get extra information:

Although as soon as once more, a web-based JSON parser ought to work superb to provide you an in depth error message.

That helps if the JSON is invalid, however should you put a JSON string worth the place an object is predicted (e.g. {"key": "string"} vs {"key": {"subkey": "string"}}), I don’t suppose it will assist except you might have a JSON schema definition.

1 Like

Ah good name – I incorrectly assumed it was invalid JSON as a result of map[string]*json.RawMessage is fairly versatile (it may deal with each the examples you talked about simply superb). However you’re completely proper – it’s legitimate JSON to have solely an array as top-level textual content:

And in that case, map[string] would break.


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