.NETで動画をGIFファイルに変換するアプリの開発

public class FakeConvertConditionRepository : IConvertConditionRepository
{
    private readonly List<IConvertCondition> conditions = new List<IConvertCondition>();

    public FakeConvertConditionRepository()
    {
        this.conditions.Add(new ConvertCondition());
    }

    public Task AddConvertConditionAsync(IConvertCondition convertCondition)
    {
        convertCondition.Id = 0;
        this.conditions.Clear();
        this.conditions.Add(convertCondition);
        return Task.CompletedTask;
    }

    public Task DeleteConvertConditionAsync(int id)
    {
        var toDelete = this.conditions.FirstOrDefault(f => f.Id == id);
        if (toDelete is not null)
        {
            this.conditions.Remove(toDelete);
        }
        return Task.CompletedTask;
    }

    public Task<IConvertCondition?> GetConvertConditionAsync(int id)
    {
        return Task.FromResult<IConvertCondition?>(this.conditions.FirstOrDefault(f => f.Id == id));
    }

    public Task UpdateConvertConditionAsync(int id, IConvertCondition convertCondition)
    {
        var toUpdate = this.conditions.FirstOrDefault(f => f.Id == id);
        if (toUpdate is not null)
        {
            toUpdate.UpdateFrom(convertCondition);
        }

        return Task.CompletedTask;
    }
}

using NSubstitute;
using SimpleGIFMaker.Domains;
using SimpleGIFMaker.Domains.Repositories;
using SimpleGIFMaker.ViewModels;
using System;
using Xunit;

namespace SimpleGIFMaker.Tests.UseCases
{
    public class uc000_SelectMovieFileTests : IDisposable
    {
        private bool disposedValue;
        private ConvertControlViewModel vm;
        private IMediaPlayer mediaPlayer;
        private IConvertConditionRepository convertConditionRepository;
        private IGifFileRepository gifFileRepository;
        private IMovieRepository movieRepository;

        public uc000_SelectMovieFileTests()
        {
            this.mediaPlayer = Substitute.For<IMediaPlayer>();
            this.convertConditionRepository = Substitute.For<IConvertConditionRepository>();
            this.gifFileRepository = Substitute.For<IGifFileRepository>();
            this.movieRepository = Substitute.For<IMovieRepository>();

            this.vm = new ConvertControlViewModel(this.mediaPlayer, this.movieRepository, this.convertConditionRepository, this.gifFileRepository);
        }

        [Fact]
        public async void FileSelect()
        {
            //
            var movieMock = Substitute.For<IMovie>();
            this.vm.selectMovieFileFunc = () => movieMock;

            //
            await this.vm.SelectFile();

            //
            await this.movieRepository.Received().AddMovieAsync(movieMock);
            await this.convertConditionRepository.Received().AddConvertConditionAsync(Arg.Any<IConvertCondition>());
            this.mediaPlayer.Received().SetMovie(movieMock);
        }

        [Fact]
        public async void FileSelectCancel()
        {
            //
            this.vm.selectMovieFileFunc = () => null;

            //
            await this.vm.SelectFile();

            //
            await this.movieRepository.DidNotReceive().AddMovieAsync(Arg.Any<IMovie>());
            this.mediaPlayer.DidNotReceive().SetMovie(Arg.Any<IMovie>());
        }

        protected virtual void Dispose(bool disposing)
        {
            if (!disposedValue)
            {
                if (disposing)
                {
                }

                disposedValue = true;
            }
        }

        public void Dispose()
        {
            // このコードを変更しないでください。クリーンアップ コードを 'Dispose(bool disposing)' メソッドに記述します
            Dispose(disposing: true);
            GC.SuppressFinalize(this);
        }
    }
}

namespace SimpleGIFMaker.DataSource.FileSystem
{
    public class FsConvertConditionRepository : IConvertConditionRepository
    {
        private string jsonDirPath = string.Empty;

        public FsConvertConditionRepository()
        {
            this.jsonDirPath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "output");
            if (Directory.Exists(jsonDirPath) == false)
            {
                Directory.CreateDirectory(jsonDirPath);
            }
        }

        public Task AddConvertConditionAsync(IConvertCondition convertCondition)
        {
            convertCondition.Id = 0;
            var dto = ConvertConditionDto.CreateFrom(convertCondition);

            var jsonFileName = $"condition_{convertCondition.Id}.json";
            var jsonPath = Path.Combine(this.jsonDirPath, jsonFileName);
            JsonFile.Save(dto, jsonPath);
            return Task.CompletedTask;
        }

        public Task DeleteConvertConditionAsync(int id)
        {
            var jsonFileName = $"condition_{id}.json";
            var jsonPath = Path.Combine(this.jsonDirPath, jsonFileName);
            if (File.Exists(jsonPath) == false)
            {
                return Task.CompletedTask;
            }

            File.Delete(jsonPath);
            return Task.CompletedTask;
        }

        public Task<IConvertCondition?> GetConvertConditionAsync(int id)
        {
            var jsonFileName = $"condition_{id}.json";
            var jsonPath = Path.Combine(this.jsonDirPath, jsonFileName);
            var dto = JsonFile.Load<ConvertConditionDto>(jsonPath);
            if (dto == null)
            {
                return Task.FromResult<IConvertCondition?>(null);
            }

            var condition = dto.Create();
            return Task.FromResult<IConvertCondition?>(condition);
        }

        public Task UpdateConvertConditionAsync(int id, IConvertCondition convertCondition)
        {
            var toUpdate = GetConvertConditionAsync(id).GetAwaiter().GetResult();
            if (toUpdate is not null)
            {
                toUpdate.UpdateFrom(convertCondition);

                var dto = ConvertConditionDto.CreateFrom(convertCondition);

                var jsonFileName = $"condition_{convertCondition.Id}.json";
                var jsonPath = Path.Combine(this.jsonDirPath, jsonFileName);
                JsonFile.Save(dto, jsonPath);
            }
            return Task.CompletedTask;
        }
    }
}