Get by id entity test

Diligent.WebAPI.Tests/Services/AdServiceTests.cs

             await Assert.ThrowsAsync<EntityNotFoundException>(async () => await adService.GetByIdAsync(1000));
         }
 
+        [Fact]
+        public async Task GetByIdEntity_ShouldReturnAd_WhenAdExists()
+        {
+            var databaseContext = await Helpers<Ad>.GetDatabaseContext(_ads);
+            AdService adService = new(databaseContext, _mapper, _technologyService, _logger);
+
+            var result = await adService.GetByIdEntityAsync(1);
+
+            result.Should().BeEquivalentTo(_ad);
+        }
+
+        [Fact]
+        public async Task GetByIdEntity_ShouldThrowEntityNotFoundException_WhenAdDontExists()
+        {
+            var databaseContext = await Helpers<Ad>.GetDatabaseContext(_ads);
+            AdService adService = new(databaseContext, _mapper, _technologyService, _logger);
+
+            await Assert.ThrowsAsync<EntityNotFoundException>(async () => await adService.GetByIdEntityAsync(1000));
+        }
+
         [Fact]
         public async Task GetAdDetailsById_ShouldReturnAd_WhenAdExists()
         {