fix(cli): resolve CLI-008..013 — format validation, exit-code semantics, debug-stream cancellation/disposal, test coverage

tests/ScadaLink.CLI.Tests/DebugStreamTests.cs

@@ -0,0 +1,100 @@
+using System.Threading.Tasks;
+using ScadaLink.CLI.Commands;
+
+namespace ScadaLink.CLI.Tests;
+
+/// <summary>
+/// Regression tests for the testable pieces of <c>DebugCommands.StreamDebugAsync</c>:
+/// CLI-010 (Ctrl+C during connect misreported as a connection failure) and
+/// CLI-012 (non-deterministic exit code after stream termination).
+/// </summary>
+public class DebugStreamTests
+{
+    // --- CLI-010: connect-failure classification --------------------------------------
+
+    [Fact]
+    public void ClassifyConnectFailure_OperationCanceled_IsTreatedAsCancellation()
+    {
+        // Ctrl+C while StartAsync is still establishing the connection throws
+        // OperationCanceledException — this is a graceful cancellation, not a failure.
+        var result = DebugStreamHelpers.ClassifyConnectFailure(
+            new OperationCanceledException(), cancellationRequested: true);
+
+        Assert.True(result.IsCancellation);
+        Assert.Equal(0, result.ExitCode);
+    }
+
+    [Fact]
+    public void ClassifyConnectFailure_TaskCanceled_WhenCancelRequested_IsCancellation()
+    {
+        var result = DebugStreamHelpers.ClassifyConnectFailure(
+            new TaskCanceledException(), cancellationRequested: true);
+
+        Assert.True(result.IsCancellation);
+        Assert.Equal(0, result.ExitCode);
+    }
+
+    [Fact]
+    public void ClassifyConnectFailure_RealException_IsConnectionFailure()
+    {
+        var result = DebugStreamHelpers.ClassifyConnectFailure(
+            new HttpRequestException("connection refused"), cancellationRequested: false);
+
+        Assert.False(result.IsCancellation);
+        Assert.Equal(1, result.ExitCode);
+    }
+
+    [Fact]
+    public void ClassifyConnectFailure_CanceledExceptionButNoCancelRequested_IsConnectionFailure()
+    {
+        // A cancellation that did not originate from the user (e.g. a server-side abort)
+        // is still a real connection failure.
+        var result = DebugStreamHelpers.ClassifyConnectFailure(
+            new OperationCanceledException(), cancellationRequested: false);
+
+        Assert.False(result.IsCancellation);
+        Assert.Equal(1, result.ExitCode);
+    }
+
+    // --- CLI-012: deterministic exit-code resolution ----------------------------------
+
+    [Fact]
+    public async Task ResolveStreamExitCodeAsync_TerminationResultSet_PrefersThatResult()
+    {
+        // OnStreamTerminated set exitTcs to 1 — that must win even on the Ctrl+C path.
+        var tcs = new TaskCompletionSource<int>();
+        tcs.SetResult(1);
+
+        var code = await DebugStreamHelpers.ResolveStreamExitCodeAsync(tcs.Task);
+
+        Assert.Equal(1, code);
+    }
+
+    [Fact]
+    public async Task ResolveStreamExitCodeAsync_NoResult_ReturnsZero()
+    {
+        // Pure Ctrl+C: exitTcs never completed — graceful shutdown, exit 0.
+        var tcs = new TaskCompletionSource<int>();
+
+        var code = await DebugStreamHelpers.ResolveStreamExitCodeAsync(tcs.Task);
+
+        Assert.Equal(0, code);
+    }
+
+    [Fact]
+    public async Task ResolveStreamExitCodeAsync_ResultArrivesDuringGrace_IsObserved()
+    {
+        // A stream termination racing with Ctrl+C: the result lands shortly after the
+        // wait was cancelled. The grace period must let it be observed deterministically.
+        var tcs = new TaskCompletionSource<int>();
+        _ = Task.Run(async () =>
+        {
+            await Task.Delay(20);
+            tcs.TrySetResult(1);
+        });
+
+        var code = await DebugStreamHelpers.ResolveStreamExitCodeAsync(tcs.Task);
+
+        Assert.Equal(1, code);
+    }
+}