tests in ApplicantsRepositoryTests.cs for FindByUserId method

SchengenVisaApi/VisaApiTests/Database/Repositories/ApplicantsRepositoryTests.cs

@@ -0,0 +1,55 @@
+using ApplicationLayer.InfrastructureServicesInterfaces;
+using ApplicationLayer.Services.Applicants.NeededServices;
+using FluentAssertions;
+using Infrastructure.Database;
+using Infrastructure.Database.Applicants.Repositories;
+using Infrastructure.Database.Applicants.Repositories.Exceptions;
+using VisaApi.Fakers;
+using VisaApi.Services;
+
+namespace VisaApi.Database.Repositories
+{
+    public class ApplicantsRepositoryTests
+    {
+        private static IApplicantsRepository GetRepository(DbContext context)
+            => new ApplicantsRepository(context, context);
+
+        private static IDateTimeProvider GetDateTimeProvider() => new TestDateTimeProvider();
+
+        [Fact]
+        private async Task FindByUserIdForNotExistingShouldThrow()
+        {
+            await using var context = InMemoryContextProvider.GetDbContext();
+            var repository = GetRepository(context);
+            ApplicantNotFoundByUserIdException? result = null;
+
+            try
+            {
+                await repository.FindByUserIdAsync(Guid.NewGuid(), CancellationToken.None);
+            }
+            catch (Exception e)
+            {
+                result = e as ApplicantNotFoundByUserIdException;
+            }
+
+            result.Should().NotBeNull();
+        }
+
+        [Fact]
+        private async Task FindByUserIdForExistingShouldReturnApplicant()
+        {
+            await using var context = InMemoryContextProvider.GetDbContext();
+            var repository = GetRepository(context);
+            var user = new UserFaker().Generate();
+            var applicant = new ApplicantFaker(GetDateTimeProvider()).Generate();
+            applicant.UserId = user.Id;
+            await context.AddAsync(user);
+            await repository.AddAsync(applicant, CancellationToken.None);
+            await context.SaveChangesAsync();
+
+            var result = await repository.FindByUserIdAsync(user.Id, CancellationToken.None);
+
+            result.Should().BeEquivalentTo(applicant);
+        }
+    }
+}