This was entirely generated by ChatGPT with just a few minutes of conversation. The only manual change is corrected indentation.

MyProject.cs

using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Options;
using SQLServerConnectionTest;
using System;
using System.Data.SqlClient;
using Xunit;

namespace MyProject
{
    /// <summary>
    /// The entry point of the application.
    /// </summary>
    public class Program
    {
        /// <summary>
        /// The main entry point of the application.
        /// </summary>
        /// <param name="args">Command line arguments.</param>
        public static void Main(string[] args)
        {
            CreateHostBuilder(args).Build().Run();
        }

        /// <summary>
        /// Configures and creates a host builder for the application.
        /// </summary>
        /// <param name="args">Command line arguments.</param>
        /// <returns>The configured host builder.</returns>
        public static IHostBuilder CreateHostBuilder(string[] args) =>
            Host.CreateDefaultBuilder(args)
                .ConfigureAppConfiguration((hostingContext, config) =>
                {
                    // Add the appsettings.json file to the configuration
                    config.AddJsonFile("appsettings.json", optional: false, reloadOnChange: true);
                })
                .ConfigureServices((hostContext, services) =>
                {
                    // Bind the "SQLServerConnection" section of appsettings.json to the SQLServerConnectionOptions class
                    services.Configure<SQLServerConnectionOptions>(hostContext.Configuration.GetSection("SQLServerConnection"));

                    // Register the database connection service with the DI container
                    services.AddScoped<IDatabaseConnectionService, DatabaseConnectionService>();
                });
    }

    /// <summary>
    /// Options for the SQLServer connection.
    /// </summary>
    public class SQLServerConnectionOptions
    {
        /// <summary>
        /// The connection string for the SQLServer database.
        /// </summary>
        public string ConnectionString { get; set; }
    }

    /// <summary>
    /// A service for testing connections to a SQLServer database.
    /// </summary>
    public class DatabaseConnectionService : IDatabaseConnectionService
    {
        private readonly string _connectionString;

        /// <summary>
        /// Constructs a new instance of the <see cref="DatabaseConnectionService"/> class.
        /// </summary>
        /// <param name="options">The options for the SQLServer connection.</param>
        public DatabaseConnectionService(IOptions<SQLServerConnectionOptions> options)
        {
            _connectionString = options.Value.ConnectionString;
        }

        /// <summary>
        /// Tests the connection to the SQLServer database.
        /// </summary>
        /// <returns>True if the connection was successful, false otherwise.</returns>
        public bool TestSQLServerConnection()
        {
            try
            {
                // Establish a connection to the database using the provided connection string
                using (SqlConnection conn = new SqlConnection(_connectionString))
                {
                    conn.Open();
                    return true;
                }
            }
            catch (SqlException)
            {
                return false;
            }
        }
    }

    /// <summary>
    /// Unit tests for the <see cref="DatabaseConnectionService"/> class.
    /// </summary>
    public class DatabaseConnectionServiceTests
    {
        /// <summary>
        /// Tests the <see cref="DatabaseConnectionService.TestSQLServerConnection"/> method with a valid connection string.
        /// </summary>
        [Fact]
        public void TestSQLServerConnection_WithValidConnectionString_ReturnsTrue()
        {
            // Arrange
            var service = new DatabaseConnectionService(new OptionsWrapper<SQLServerConnectionOptions>(new SQLServerConnectionOptions
            {
                ConnectionString = "Server=localhost;Database=myDatabase;User ID=myUsername;Password=myPassword;"
            }));

            // Act
            var result = service.TestSQLServerConnection();

            // Assert
            Assert.True(result);
        }

        /// <summary>
        /// Tests the <see cref="DatabaseConnectionService.TestSQLServerConnection"/> method with an invalid connection string.
        /// </summary>
        [Fact]
        public void TestSQLServerConnection_WithInvalidConnectionString_ReturnsFalse()
        {
            // Arrange
            var service = new DatabaseConnectionService(new OptionsWrapper<SQLServerConnectionOptions>(new SQLServerConnectionOptions
            {
                ConnectionString = "InvalidConnectionString"
            }));

            // Act
            var result = service.TestSQLServerConnection();

            // Assert
            Assert.False(result);
        }
    }
}