harmonia/Harmonia.Core/Data/JsonFileRepository.cs

using System.Text.Json.Serialization;
using System.Text.Json;

namespace Harmonia.Core.Data;

public abstract class JsonFileRepository<TObject> : FileRepository<TObject> where TObject : notnull, new()
{
    private readonly JsonSerializerOptions _options = new()
    {
        WriteIndented = true,
        IgnoreReadOnlyProperties = true,
        DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull
    };

    protected override string Extension => "json";

    protected override async Task<TObject> DeserializeAsync(Stream stream)
    {
        return await JsonSerializer.DeserializeAsync<TObject>(stream) ?? new();
    }

    protected override async Task<string> SerializeAsync(TObject obj)
    {
        using MemoryStream memoryStream = new();
        await JsonSerializer.SerializeAsync(memoryStream, obj, _options);

        memoryStream.Position = 0;

        using StreamReader reader = new(memoryStream);
        return await reader.ReadToEndAsync();
    }
}