jobtrackingapp/JobTrackerApi.Tests/DatabaseConfigurationTests.cs

using JobTrackerApi.Data;
using JobTrackerApi.Services;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Infrastructure;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging.Abstractions;
using Moq;
using Pomelo.EntityFrameworkCore.MySql.Infrastructure.Internal;
using Xunit;

namespace JobTrackerApi.Tests;

public sealed class DatabaseConfigurationTests
{
    private const string UnreachableMariaDb = "Server=127.0.0.1;Port=1;Database=jt_config_test;User=config_test;Password=synthetic;Connection Timeout=1";
    private static IConfiguration Config(string? provider = null, string? connection = null, string? version = null) =>
        new ConfigurationBuilder().AddInMemoryCollection(new Dictionary<string, string?>
        {
            ["Database:Provider"] = provider,
            ["ConnectionStrings:JobTracker"] = connection,
            ["Database:ServerVersion"] = version,
        }).Build();

    [Fact]
    public void Default_registration_uses_pinned_MariaDb_without_connecting_to_a_server()
    {
        var configuration = Config(connection: UnreachableMariaDb);
        var options = new DbContextOptionsBuilder<JobTrackerContext>();
        DatabaseConfiguration.Configure(options, configuration, "unused.db");
        Assert.Equal("mariadb", DatabaseConfiguration.GetProvider(configuration));
        var relational = Assert.Single(options.Options.Extensions.OfType<RelationalOptionsExtension>());
        Assert.Equal(UnreachableMariaDb, relational.ConnectionString);
        // Inspect the provider's configured version without opening a connection or generating SQL.
#pragma warning disable EF1001
        var mysql = Assert.IsType<MySqlOptionsExtension>(relational);
        Assert.IsType<MariaDbServerVersion>(mysql.ServerVersion);
        Assert.Equal(new Version(12, 2, 2), mysql.ServerVersion!.Version);
#pragma warning restore EF1001
    }

    [Theory]
    [InlineData(null)]
    [InlineData("mariadb")]
    [InlineData("mysql")]
    public void Missing_MariaDb_connection_fails_closed_instead_of_creating_a_Sqlite_database(string? provider)
    {
        var options = new DbContextOptionsBuilder<JobTrackerContext>();
        Assert.Throws<InvalidOperationException>(() => DatabaseConfiguration.Configure(options, Config(provider), "must-not-create.db"));
        Assert.Empty(options.Options.Extensions.OfType<RelationalOptionsExtension>());
    }

    [Theory]
    [InlineData("postgres")]
    [InlineData("")]
    [InlineData(" ")]
    [InlineData("maria-db")]
    public void Unknown_provider_is_rejected_even_when_a_connection_is_configured(string provider)
    {
        Assert.Throws<InvalidOperationException>(() => DatabaseConfiguration.Configure(
            new DbContextOptionsBuilder<JobTrackerContext>(), Config(provider, "Data Source=must-not-create.db"), "unused.db"));
        Assert.Throws<InvalidOperationException>(() => DatabaseConfiguration.GetProvider(Config(provider)));
    }

    [Theory]
    [InlineData("mariadb")]
    [InlineData(" MYSQL ")]
    public void MariaDb_server_version_is_configurable_without_auto_detection(string provider)
    {
        var options = new DbContextOptionsBuilder<JobTrackerContext>();
        DatabaseConfiguration.Configure(options, Config(provider, UnreachableMariaDb, "11.4.10"), "unused.db");
#pragma warning disable EF1001
        Assert.Equal(new Version(11, 4, 10), options.Options.Extensions.OfType<MySqlOptionsExtension>().Single().ServerVersion!.Version);
#pragma warning restore EF1001
    }

    [Fact]
    public void Invalid_server_version_fails_during_configuration()
    {
        Assert.Throws<InvalidOperationException>(() => DatabaseConfiguration.Configure(
            new DbContextOptionsBuilder<JobTrackerContext>(), Config("mariadb", UnreachableMariaDb, "latest"), "unused.db"));
    }

    [Theory]
    [InlineData(null, "Data Source=preserved.db")]
    [InlineData("Data Source=explicit.db", "Data Source=explicit.db")]
    public void Explicit_Sqlite_preserves_existing_file_selection(string? connection, string expected)
    {
        var options = new DbContextOptionsBuilder<JobTrackerContext>();
        DatabaseConfiguration.Configure(options, Config(" SQLITE ", connection), "preserved.db");
        var relational = Assert.Single(options.Options.Extensions.OfType<RelationalOptionsExtension>());
        Assert.Equal("SqliteOptionsExtension", relational.GetType().Name);
        Assert.Equal(expected, relational.ConnectionString);
    }

    [Fact]
    public async Task Default_MariaDb_backup_selection_cannot_run_the_Sqlite_backup_path()
    {
        var root = Path.Combine(Path.GetTempPath(), $"jt-config-backup-{Guid.NewGuid():N}");
        var configuration = new ConfigurationBuilder().AddConfiguration(Config(connection: UnreachableMariaDb))
            .AddInMemoryCollection(new Dictionary<string, string?> { ["Data:Root"] = root }).Build();
        var environment = new Mock<IHostEnvironment>();
        environment.SetupGet(x => x.ContentRootPath).Returns(root);
        try
        {
            var runner = new SqliteDatabaseBackupRunner(configuration, new AppPaths(configuration, environment.Object), NullLogger<SqliteDatabaseBackupRunner>.Instance);
            Assert.False(runner.IsSupported);
            Assert.Null(await runner.RunOnceAsync(default));
            Assert.False(Directory.Exists(runner.BackupsRoot));
        }
        finally { if (Directory.Exists(root)) Directory.Delete(root, true); }
    }
}