Fix Galaxy paging review findings

clients/dotnet/MxGateway.Client.Cli/MxGatewayClientCli.cs

@@ -814,9 +814,7 @@ public static class MxGatewayClientCli
         TextWriter output,
         CancellationToken cancellationToken)
     {
-        DiscoverHierarchyReply reply = await client.GalaxyDiscoverHierarchyAsync(
-                new DiscoverHierarchyRequest(),
-                cancellationToken)
+        DiscoverHierarchyReply reply = await DiscoverAllGalaxyHierarchyAsync(client, cancellationToken)
             .ConfigureAwait(false);
 
         if (arguments.HasFlag("json"))
@@ -834,6 +832,39 @@ public static class MxGatewayClientCli
         return 0;
     }
 
+    private static async Task<DiscoverHierarchyReply> DiscoverAllGalaxyHierarchyAsync(
+        IMxGatewayCliClient client,
+        CancellationToken cancellationToken)
+    {
+        DiscoverHierarchyReply aggregate = new();
+        HashSet<string> seenPageTokens = new(StringComparer.Ordinal);
+        string pageToken = string.Empty;
+        do
+        {
+            DiscoverHierarchyReply page = await client.GalaxyDiscoverHierarchyAsync(
+                    new DiscoverHierarchyRequest
+                    {
+                        PageSize = 5000,
+                        PageToken = pageToken,
+                    },
+                    cancellationToken)
+                .ConfigureAwait(false);
+
+            aggregate.Objects.Add(page.Objects);
+            aggregate.TotalObjectCount = page.TotalObjectCount;
+            pageToken = page.NextPageToken;
+            if (!string.IsNullOrWhiteSpace(pageToken)
+                && !seenPageTokens.Add(pageToken))
+            {
+                throw new MxGatewayException(
+                    $"Galaxy DiscoverHierarchy returned a repeated page token '{pageToken}'.");
+            }
+        }
+        while (!string.IsNullOrWhiteSpace(pageToken));
+
+        return aggregate;
+    }
+
     private static async Task<int> GalaxyWatchAsync(
         CliArguments arguments,
         IMxGatewayCliClient client,

clients/dotnet/MxGateway.Client.Tests/GalaxyRepositoryClientTests.cs

@@ -140,6 +140,26 @@ public sealed class GalaxyRepositoryClientTests
         Assert.False(call.CallOptions.CancellationToken.IsCancellationRequested);
     }
 
+    [Fact]
+    public async Task DiscoverHierarchyAsync_WithRepeatedPageToken_ThrowsProtocolError()
+    {
+        FakeGalaxyRepositoryTransport transport = CreateTransport();
+        transport.DiscoverHierarchyReplies.Enqueue(new DiscoverHierarchyReply
+        {
+            NextPageToken = "7:1",
+        });
+        transport.DiscoverHierarchyReplies.Enqueue(new DiscoverHierarchyReply
+        {
+            NextPageToken = "7:1",
+        });
+        await using GalaxyRepositoryClient client = CreateClient(transport);
+
+        MxGatewayException exception = await Assert.ThrowsAsync<MxGatewayException>(
+            async () => await client.DiscoverHierarchyAsync());
+
+        Assert.Contains("repeated page token", exception.Message, StringComparison.Ordinal);
+    }
+
     [Fact]
     public async Task TestConnectionAsync_RetriesOnTransientGrpcFailure()
     {

clients/dotnet/MxGateway.Client.Tests/MxGatewayClientCliTests.cs

@@ -207,8 +207,10 @@ public sealed class MxGatewayClientCliTests
         using var output = new StringWriter();
         using var error = new StringWriter();
         FakeCliClient fakeClient = new();
-        fakeClient.GalaxyDiscoverHierarchyReply = new DiscoverHierarchyReply
+        fakeClient.GalaxyDiscoverHierarchyReplies.Enqueue(new DiscoverHierarchyReply
         {
+            NextPageToken = "7:1",
+            TotalObjectCount = 2,
             Objects =
             {
                 new GalaxyObject
@@ -227,7 +229,21 @@ public sealed class MxGatewayClientCliTests
                     },
                 },
             },
-        };
+        });
+        fakeClient.GalaxyDiscoverHierarchyReplies.Enqueue(new DiscoverHierarchyReply
+        {
+            TotalObjectCount = 2,
+            Objects =
+            {
+                new GalaxyObject
+                {
+                    GobjectId = 8,
+                    TagName = "DelmiaReceiver_002",
+                    ContainedName = "DelmiaReceiver",
+                    ParentGobjectId = 1,
+                },
+            },
+        });
 
         int exitCode = await MxGatewayClientCli.RunAsync(
             [
@@ -242,10 +258,14 @@ public sealed class MxGatewayClientCliTests
             _ => fakeClient);
 
         Assert.Equal(0, exitCode);
-        Assert.Single(fakeClient.GalaxyDiscoverHierarchyRequests);
+        Assert.Equal(2, fakeClient.GalaxyDiscoverHierarchyRequests.Count);
+        Assert.Equal(5000, fakeClient.GalaxyDiscoverHierarchyRequests[0].PageSize);
+        Assert.Equal("", fakeClient.GalaxyDiscoverHierarchyRequests[0].PageToken);
+        Assert.Equal("7:1", fakeClient.GalaxyDiscoverHierarchyRequests[1].PageToken);
         string text = output.ToString();
-        Assert.Contains("objects=1", text);
+        Assert.Contains("objects=2", text);
         Assert.Contains("DelmiaReceiver_001", text);
+        Assert.Contains("DelmiaReceiver_002", text);
         Assert.Contains("attributes=1", text);
         Assert.Equal(string.Empty, error.ToString());
     }
@@ -411,6 +431,8 @@ public sealed class MxGatewayClientCliTests
 
         public DiscoverHierarchyReply GalaxyDiscoverHierarchyReply { get; set; } = new();
 
+        public Queue<DiscoverHierarchyReply> GalaxyDiscoverHierarchyReplies { get; } = new();
+
         public List<TestConnectionRequest> GalaxyTestConnectionRequests { get; } = [];
 
         public List<GetLastDeployTimeRequest> GalaxyGetLastDeployTimeRequests { get; } = [];
@@ -438,7 +460,10 @@ public sealed class MxGatewayClientCliTests
             CancellationToken cancellationToken)
         {
             GalaxyDiscoverHierarchyRequests.Add(request);
-            return Task.FromResult(GalaxyDiscoverHierarchyReply);
+            return Task.FromResult(
+                GalaxyDiscoverHierarchyReplies.TryDequeue(out DiscoverHierarchyReply? reply)
+                    ? reply
+                    : GalaxyDiscoverHierarchyReply);
         }
 
         public List<WatchDeployEventsRequest> GalaxyWatchDeployEventsRequests { get; } = [];

clients/dotnet/MxGateway.Client/GalaxyRepositoryClient.cs

@@ -146,6 +146,7 @@ public sealed class GalaxyRepositoryClient : IAsyncDisposable
     public async Task<IReadOnlyList<GalaxyObject>> DiscoverHierarchyAsync(CancellationToken cancellationToken = default)
     {
         List<GalaxyObject> objects = [];
+        HashSet<string> seenPageTokens = new(StringComparer.Ordinal);
         string pageToken = string.Empty;
         do
         {
@@ -160,6 +161,12 @@ public sealed class GalaxyRepositoryClient : IAsyncDisposable
 
             objects.AddRange(reply.Objects);
             pageToken = reply.NextPageToken;
+            if (!string.IsNullOrWhiteSpace(pageToken)
+                && !seenPageTokens.Add(pageToken))
+            {
+                throw new MxGatewayException(
+                    $"Galaxy DiscoverHierarchy returned a repeated page token '{pageToken}'.");
+            }
         }
         while (!string.IsNullOrWhiteSpace(pageToken));