steves-bot/src/StevesBot.Worker.Tests/Unit/WelcomeMessageHandlerTests.cs

using StevesBot.Worker.Handlers;

namespace StevesBot.Worker.Tests.Unit;

public class WelcomeMessageHandlerTests
{
  private readonly Mock<IDiscordRestClient> _mockDiscordRestClient = new();
  private readonly Mock<ILogger<IDiscordGatewayClient>> _mockLogger = new();
  private readonly IServiceProvider _serviceProvider;

  public WelcomeMessageHandlerTests()
  {
    var serviceCollection = new ServiceCollection();
    serviceCollection.AddSingleton(_mockDiscordRestClient.Object);
    serviceCollection.AddSingleton(_mockLogger.Object);

    _serviceProvider = serviceCollection.BuildServiceProvider();
  }

  [Fact]
  public async Task HandleAsync_WhenEventIsNotMessageCreateEvent_ItShouldNotCreateMessage()
  {
    await WelcomeMessageHandler.HandleAsync(new DiscordEvent(), _serviceProvider);

    _mockDiscordRestClient
      .Verify(
        static c => c.CreateMessageAsync(It.IsAny<string>(), It.IsAny<CreateMessageRequest>(), It.IsAny<CancellationToken>()),
        Times.Never
      );
  }

  [Fact]
  public async Task HandleAsync_WhenMessageCreateEventIsNotAUserJoinMessage_ItShouldNotCreateMessage()
  {
    var @event = new MessageCreateDiscordEvent()
    {
      Data = new()
      {
        Type = -1,
      },
    };

    await WelcomeMessageHandler.HandleAsync(@event, _serviceProvider);

    _mockDiscordRestClient
      .Verify(
        static c => c.CreateMessageAsync(It.IsAny<string>(), It.IsAny<CreateMessageRequest>(), It.IsAny<CancellationToken>()),
        Times.Never
      );
  }

  [Fact]
  public async Task HandleAsync_WhenUserJoinMessageCreateEventReceived_ItShouldCreateWelcomeMessage()
  {
    _mockDiscordRestClient
      .Setup(static c => c.CreateMessageAsync(It.IsAny<string>(), It.IsAny<CreateMessageRequest>(), It.IsAny<CancellationToken>()))
      .ReturnsAsync(new DiscordMessage());

    var @event = new MessageCreateDiscordEvent()
    {
      Data = new()
      {
        Type = DiscordMessageTypes.UserJoin,
        Id = Guid.NewGuid().ToString(),
        ChannelId = Guid.NewGuid().ToString(),
        GuildId = Guid.NewGuid().ToString(),
        Author = new()
        {
          Id = Guid.NewGuid().ToString(),
        }
      }
    };

    await WelcomeMessageHandler.HandleAsync(@event, _serviceProvider);

    _mockDiscordRestClient
      .Verify(
        static c => c.CreateMessageAsync(It.IsAny<string>(), It.IsAny<CreateMessageRequest>(), It.IsAny<CancellationToken>()),
        Times.Once
      );
  }
}