How to pretty print using System.Text.Json for unknown object

Question

Using System.Text.Json i can pretty print json using serialization option.

var options = new JsonSerializerOptions{ WriteIndented = true };
jsonString = JsonSerializer.Serialize(typeToSerialize, options);

However, I have string JSON and don't know the concrete type. Ho do I pretty-print JSON string?

My old code was using Newtonsoft and I could do it without serialize/deserialize

public static string JsonPrettify(this string json)
{
    if (string.IsNullOrEmpty(json))
    {
        return json;
    }

    using (var stringReader = new StringReader(json))
    using (var stringWriter = new StringWriter())
    {
        var jsonReader = new JsonTextReader(stringReader);
        var jsonWriter = new JsonTextWriter(stringWriter) { Formatting = Formatting.Indented };
        jsonWriter.WriteToken(jsonReader);
        return stringWriter.ToString();
    }
}

Answer 1

This works:

using System.Text.Json;
public static string JsonPrettify(this string json)
{
    using var jDoc = JsonDocument.Parse(json);
    return JsonSerializer.Serialize(jDoc, new JsonSerializerOptions { WriteIndented = true });
}