Shogi/Shogi.UI/Shared/LocalStorage.cs

using Microsoft.JSInterop;
using System.Text.Json;
using System.Text.Json.Serialization;

namespace Shogi.UI.Shared;

public class LocalStorage : ILocalStorage
{
	private readonly JsonSerializerOptions jsonOptions;
	private readonly IJSRuntime jSRuntime;

	public LocalStorage(IJSRuntime jSRuntime)
	{
		this.jsonOptions = new JsonSerializerOptions();
		this.jsonOptions.Converters.Add(new JsonStringEnumConverter());
		this.jSRuntime = jSRuntime;
	}

	public ValueTask Set<T>(string key, T value)
	{
		var serialized = JsonSerializer.Serialize(value);
		return this.jSRuntime.InvokeVoidAsync("localStorage.setItem", key, serialized);
	}

	public async ValueTask<T?> Get<T>(string key) where T : struct
	{

		var value = await this.jSRuntime.InvokeAsync<string>("localStorage.getItem", key);
		try
		{
			return JsonSerializer.Deserialize<T>(value, this.jsonOptions);
		}
		catch (ArgumentNullException)
		{
			return default;
		}
	}

	public ValueTask Delete(string key)
	{
		return this.jSRuntime.InvokeVoidAsync("localStorage.removeItem", key);
	}
}

public interface ILocalStorage
{
	ValueTask Delete(string key);
	ValueTask<T?> Get<T>(string key) where T : struct;
	ValueTask Set<T>(string key, T value);
}