MongoTestBase: add proper client cleanup, some refactoring

tests/TPP.Persistence.MongoDB.Tests/Repos/MongoTestBase.cs

@@ -4,57 +4,58 @@
 using System.Threading;
 using System.Threading.Tasks;
 using MongoDB.Driver;
-using MongoDB.Driver.Linq;
 using NUnit.Framework;
 using TPP.Persistence.MongoDB.Serializers;
 
-namespace TPP.Persistence.MongoDB.Tests.Repos
+namespace TPP.Persistence.MongoDB.Tests.Repos;
+
+/// <summary>
+/// Base class for tests that need to operate on an actual MongoDB server.
+/// Connects to a local mongod instance running on the default port (27017).
+/// Provides a CreateTemporaryDatabase method for obtaining a unique IMongoDatabase.
+/// Databases created that way get cleaned up while the test class is being torn down.
+/// </summary>
+[Category("IntegrationTest")]
+public abstract class MongoTestBase
 {
-    /// <summary>
-    /// Base class for tests that need to operate on an actual MongoDB server.
-    /// Connects to a local mongod instance running on the default port (27017).
-    /// Provides a CreateTemporaryDatabase method for obtaining a unique IMongoDatabase.
-    /// Databases created that way get cleaned up while the test class is being torn down.
-    /// </summary>
-    [Category("IntegrationTest")]
-    public abstract class MongoTestBase
-    {
-        private const string ReplicaSetName = "rs0";
-        private static readonly Random Random = new Random();
+    private const string ReplicaSetName = "rs0";
+    private static readonly Random Random = new();
 
-        private MongoClient _client = null!;
-        private readonly List<string> _temporaryDatabases = new List<string>();
+    private MongoClient _client = null!;
+    private readonly List<string> _temporaryDatabases = [];
 
-        [OneTimeSetUp]
-        public void SetUpMongoClient()
+    [OneTimeSetUp]
+    public void SetUpMongoClient()
+    {
+        CustomSerializers.RegisterAll();
+        // try to connect to a mongodb running on the default port
+        MongoClientSettings settings = MongoClientSettings
+            .FromConnectionString($"mongodb://localhost:27017/?replicaSet={ReplicaSetName}");
+        _client = new MongoClient(settings);
+        bool success = _client.ListDatabaseNamesAsync(CancellationToken.None).Wait(TimeSpan.FromSeconds(5));
+        if (!success)
         {
-            CustomSerializers.RegisterAll();
-            // try to connect to a mongodb running on the default port
-            MongoClientSettings settings = MongoClientSettings
-                .FromConnectionString($"mongodb://localhost:27017/?replicaSet={ReplicaSetName}");
-            _client = new MongoClient(settings);
-            bool success = _client.ListDatabaseNamesAsync(CancellationToken.None).Wait(TimeSpan.FromSeconds(5));
-            if (!success)
-            {
-                throw new AssertionException(
-                    "Failed to connect to a local MongoDB instance running on the default port. " +
-                    "Please start a local MongoDB instance on the default port (27017), " +
-                    $"and make sure it is in replica set mode with a replica set named '{ReplicaSetName}'. " +
-                    "Alternatively, skip these tests using 'dotnet test --filter TestCategory!=IntegrationTest'");
-            }
+            throw new AssertionException(
+                "Failed to connect to a local MongoDB instance running on the default port. " +
+                "Please start a local MongoDB instance on the default port (27017), " +
+                $"and make sure it is in replica set mode with a replica set named '{ReplicaSetName}'. " +
+                "Alternatively, skip these tests using 'dotnet test --filter TestCategory!=IntegrationTest'");
         }
+    }
 
-        [OneTimeTearDown]
-        public void TearDownTempDatabases()
-        {
-            Task.WhenAll(_temporaryDatabases.Select(db => _client.DropDatabaseAsync(db))).Wait();
-        }
+    [OneTimeTearDown]
+    public void TearDownTempDatabases()
+    {
+        // ReSharper disable once AccessToDisposedClosure : task is Wait()-ed on before client gets disposed.
+        IEnumerable<Task> dropTasks = _temporaryDatabases.Select(db => _client.DropDatabaseAsync(db));
+        Task.WhenAll(dropTasks).Wait();
+        _client.Dispose();
+    }
 
-        protected IMongoDatabase CreateTemporaryDatabase()
-        {
-            string dbName = "testdb-" + Random.Next();
-            _temporaryDatabases.Add(dbName);
-            return _client.GetDatabase(dbName);
-        }
+    protected IMongoDatabase CreateTemporaryDatabase()
+    {
+        string dbName = "testdb-" + Random.Next();
+        _temporaryDatabases.Add(dbName);
+        return _client.GetDatabase(dbName);
     }
 }