fix(MongoDb): Treat an already initiated replica set as success

src/Testcontainers.MongoDb/MongoDbBuilder.cs

@@ -204,7 +204,11 @@ private static async Task InitiateReplicaSetAsync(MongoDbContainer container, Mo
         // with custom configurations as needed.
         var options = new WaitStrategy();
 
-        var scriptContent = $"var r=rs.initiate({{_id:\"{configuration.ReplicaSetName}\",members:[{{_id:0,host:\"127.0.0.1:27017\"}}]}});quit(r.ok===1?0:1);";
+        // The startup callback runs on every start, so a container that is restarted or reused
+        // already holds an initiated replica set. Initiating it again throws instead of returning
+        // a result, which would otherwise be retried until the wait strategy times out:
+        // https://github.com/testcontainers/testcontainers-dotnet/issues/1722.
+        var scriptContent = $"try{{var r=rs.initiate({{_id:\"{configuration.ReplicaSetName}\",members:[{{_id:0,host:\"127.0.0.1:27017\"}}]}});quit(r.ok===1?0:1);}}catch(e){{quit(e.codeName===\"AlreadyInitialized\"?0:1);}}";
 
         var initiate = async () =>
         {

tests/Testcontainers.MongoDb.Tests/MongoDbReplicaSetReuseTest.cs

@@ -0,0 +1,72 @@
+namespace Testcontainers.MongoDb;
+
+/// <summary>
+/// Reusing a container runs the startup callback again against a replica set that is already
+/// initiated (https://github.com/testcontainers/testcontainers-dotnet/issues/1722).
+/// </summary>
+public sealed class MongoDbReplicaSetReuseTest : IAsyncLifetime
+{
+    private readonly string _labelKey = Guid.NewGuid().ToString("D");
+
+    private readonly string _labelValue = Guid.NewGuid().ToString("D");
+
+    private readonly IList<MongoDbContainer> _containers = new List<MongoDbContainer>();
+
+    public ValueTask InitializeAsync()
+    {
+        return ValueTask.CompletedTask;
+    }
+
+    public async ValueTask DisposeAsync()
+    {
+        foreach (var container in _containers.Distinct())
+        {
+            await container.DisposeAsync()
+                .ConfigureAwait(false);
+        }
+
+        GC.SuppressFinalize(this);
+    }
+
+    [Fact]
+    [Trait(nameof(DockerCli.DockerPlatform), nameof(DockerCli.DockerPlatform.Linux))]
+    public async Task ReusedContainerStartsAgain()
+    {
+        // Given
+        // The default wait strategy timeout is one hour, so bound the wait to keep a regression
+        // from hanging the test run instead of failing it.
+        using var cts = new CancellationTokenSource(TimeSpan.FromMinutes(3));
+
+        var container = CreateContainer();
+        _containers.Add(container);
+
+        await container.StartAsync(cts.Token)
+            .ConfigureAwait(true);
+
+        // When
+        var reusedContainer = CreateContainer();
+        _containers.Add(reusedContainer);
+
+        await reusedContainer.StartAsync(cts.Token)
+            .ConfigureAwait(true);
+
+        // Then
+        Assert.Equal(container.Id, reusedContainer.Id);
+
+        const string scriptContent = "rs.status().ok;";
+
+        var execResult = await reusedContainer.ExecScriptAsync(scriptContent, cts.Token)
+            .ConfigureAwait(true);
+
+        Assert.True(0L.Equals(execResult.ExitCode), execResult.Stderr);
+    }
+
+    private MongoDbContainer CreateContainer()
+    {
+        return new MongoDbBuilder(TestSession.GetImageFromDockerfile())
+            .WithReplicaSet()
+            .WithLabel(_labelKey, _labelValue)
+            .WithReuse(true)
+            .Build();
+    }
+}

tests/Testcontainers.MongoDb.Tests/Usings.cs

@@ -1,4 +1,7 @@
 global using System;
+global using System.Collections.Generic;
+global using System.Linq;
+global using System.Threading;
 global using System.Threading.Tasks;
 global using DotNet.Testcontainers.Commons;
 global using DotNet.Testcontainers.Configurations;