Is there a way to pretty print arbitrary JSON with...

# serialization

[Marcin Wisniowski]

Is there a way to pretty print arbitrary JSON with kotlinx.serialisation? I have a String with some JSON, I want to format it into a formatted String to pretty print. I don't care about the content of the JSON, it can be anything.

In GSON, this is achieved with: JsonParser.parse to parse any JSON and then gson.toJson(parsed), to print, with the GSON instance using pretty printing.
In kotlinx.serialisation, we can also parse arbitrary JSON with json.parseToJsonElement, and then print it with JsonElement.toString(). But the printing doesn't use the Json instance and so doesn't use the pretty-printing setting that is enabled on it.

[Vampire]

I guess

val json = Json { prettyPrint = true }
val prettyPrinted = json.encodeToString(json.parseToJsonElement("{ my: json }"))

[Marcin Wisniowski]

Ah, JsonElement can be passed to encodeToString, I didn't realize that.

[Vampire]

I didn't try, but that's my guess 🙂

[Marcin Wisniowski]

Can confirm it works, thank you.

[farmerbb]

For anyone else that found this thread through search: you'll need to import the extension function kotlinx.serialization.encodeToString in order for this to work 👍