ASP.NET Core Integration tests code from my video: https://www.youtube.com/watch?v=7roqteWLw4s

IntegrationTest.cs

using System.Net.Http;
using System.Net.Http.Headers;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc.Testing;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.DependencyInjection.Extensions;
using Tweetbook.Contracts.V1;
using Tweetbook.Contracts.V1.Requests;
using Tweetbook.Contracts.V1.Responses;
using Tweetbook.Data;

namespace Tweetbook.IntegrationTests
{
    public class IntegrationTest
    {
        protected readonly HttpClient TestClient;
        
        protected IntegrationTest()
        {
            var appFactory = new WebApplicationFactory<Startup>()
                .WithWebHostBuilder(builder =>
                    {
                        builder.ConfigureServices(services =>
                        {
                            services.RemoveAll(typeof(DataContext));
                            services.AddDbContext<DataContext>(options => { options.UseInMemoryDatabase("TestDb"); });
                        });
                    });
            
            TestClient = appFactory.CreateClient();
        }

        protected async Task AuthenticateAsync()
        {
            TestClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("bearer", await GetJwtAsync());
        }

        protected async Task<PostResponse> CreatePostAsync(CreatePostRequest request)
        {
            var response = await TestClient.PostAsJsonAsync(ApiRoutes.Posts.Create, request);
            return await response.Content.ReadAsAsync<PostResponse>();
        }

        private async Task<string> GetJwtAsync()
        {
            var response = await TestClient.PostAsJsonAsync(ApiRoutes.Identity.Register, new UserRegistrationRequest
            {
                Email = "[email protected]",
                Password = "SomePass1234!"
            });

            var registrationResponse = await response.Content.ReadAsAsync<AuthSuccessResponse>();
            return registrationResponse.Token;
        }
    }
}

PostsControllerTests.cs

using System.Collections.Generic;
using System.Net;
using System.Net.Http;
using System.Threading.Tasks;
using FluentAssertions;
using Tweetbook.Contracts.V1;
using Tweetbook.Contracts.V1.Requests;
using Tweetbook.Domain;
using Xunit;

namespace Tweetbook.IntegrationTests
{
    public class PostsControllerTests : IntegrationTest
    {
        [Fact]
        public async Task GetAll_WithoutAnyPosts_ReturnsEmptyResponse()
        {
            // Arrange
            await AuthenticateAsync();

            // Act
            var response = await TestClient.GetAsync(ApiRoutes.Posts.GetAll);

            // Assert
            response.StatusCode.Should().Be(HttpStatusCode.OK);
            (await response.Content.ReadAsAsync<List<Post>>()).Should().BeEmpty();
        }

        [Fact]
        public async Task Get_ReturnsPost_WhenPostExistsInTheDatabase()
        {
            // Arrange
            await AuthenticateAsync();
            var createdPost = await CreatePostAsync(new CreatePostRequest {Name = "Test post"});

            // Act
            var response = await TestClient.GetAsync(ApiRoutes.Posts.Get.Replace("{postId}", createdPost.Id.ToString()));
            
            // Assert
            response.StatusCode.Should().Be(HttpStatusCode.OK);
            var returnedPost = await response.Content.ReadAsAsync<Post>();
            returnedPost.Id.Should().Be(createdPost.Id);
            returnedPost.Name.Should().Be("Test post");
        }
    }
}

Tweetbook.IntegrationTests.csproj

<Project Sdk="Microsoft.NET.Sdk">

    <PropertyGroup>
        <TargetFramework>netcoreapp2.2</TargetFramework>
        <IsPackable>false</IsPackable>
    </PropertyGroup>

    <ItemGroup>
        <PackageReference Include="FluentAssertions" Version="5.7.0" />
        <PackageReference Include="Microsoft.AspNetCore.App" Version="2.2.0" />
        <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" Version="2.2.0" />
        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.9.0" />
        <PackageReference Include="xunit" Version="2.4.0" />
        <PackageReference Include="xunit.runner.visualstudio" Version="2.4.0" />
    </ItemGroup>

    <ItemGroup>
      <ProjectReference Include="..\Tweetbook\Tweetbook.csproj" />
    </ItemGroup>
</Project>