fix: classify early stdin close after process exit

Author: KSemenenko

CodexSharpSDK.Tests/Integration/CodexWindowsNpmLaunchTests.cs

@@ -24,7 +24,7 @@ public sealed class CodexWindowsNpmLaunchTests
         "if (args.includes('--version')) { console.log('codex-cli 0.160.1'); process.exit(0); }\n" +
         "console.log(JSON.stringify({type:'thread.started', thread_id:'fixture'}));\n" +
         "console.log(JSON.stringify({type:'item.completed', item:{id:'message', type:'agent_message', text:input}}));\n" +
-        "console.log(JSON.stringify({type:'turn.completed'}));\n";
+        "console.log(JSON.stringify({type:'turn.completed',usage:{input_tokens:1,cached_input_tokens:0,output_tokens:1}}));\n";
 
     [Test]
     public async Task WindowsNpmShim_UsesNodeAndLiteralArgumentsForMetadataCoreAndMeai()

CodexSharpSDK.Tests/Unit/CodexExecTests.cs

@@ -23,13 +23,15 @@ public class CodexExecTests
     private const string DuplexPressureTemplatePlaceholder = "{0}";
     private const string PosixFixtureSkipReason = "The public CLI yield-boundary fixture currently uses a POSIX executable script.";
     private const string LinuxFixtureSkipReason = "The detached stderr-retention fixture requires Linux setsid.";
-    private const string StderrClosureFailure = "stderr stream closed";
+    private const string StderrClosureFailure = "Codex CLI process and output cleanup could not be confirmed.";
     private const string ProcessOutputLimitMessage = "Codex CLI process exceeded the configured output limit.";
     private const string PosixSingleLineOverflowCommand = "printf '%100s\\n' x; exec /bin/sleep 30";
     private const string PosixMultiLineOverflowCommand = "printf '1234567890\\n1234567890\\n1234567890\\n'";
     private const string PosixStandardErrorPressureCommand = "printf '%100s' x >&2; exec /bin/sleep 30";
     private const string PosixNormalMultiLineCommand = "printf 'first\\nsecond\\n'";
     private const string PosixNonZeroExitBeforeInputCommand = "printf 'provider failed\\n' >&2; /bin/sleep 0.1; exit 23";
+    private const string PosixZeroExitAfterClosingInputCommand = "exec 0<&-; /bin/sleep 0.1; exit 0";
+    private const string PosixStaysRunningAfterClosingInputCommand = "printf 'started\\n'; exec 0<&-; exec /bin/sleep 30";
     private const string WindowsPowerShellPath = "powershell.exe";
     private const string WindowsNoProfileFlag = "-NoProfile";
     private const string WindowsNonInteractiveFlag = "-NonInteractive";
@@ -39,6 +41,8 @@ public class CodexExecTests
     private const string WindowsStandardErrorPressureCommand = "[Console]::Error.Write('x' * 100); Start-Sleep -Seconds 30";
     private const string WindowsNormalMultiLineCommand = "Write-Output 'first'; Write-Output 'second'";
     private const string WindowsNonZeroExitBeforeInputCommand = "[Console]::Error.WriteLine('provider failed'); Start-Sleep -Milliseconds 100; exit 23";
+    private const string WindowsZeroExitAfterClosingInputCommand = "[Console]::OpenStandardInput().Dispose(); Start-Sleep -Milliseconds 100; exit 0";
+    private const string WindowsStaysRunningAfterClosingInputCommand = "Write-Output 'started'; [Console]::OpenStandardInput().Dispose(); Start-Sleep -Seconds 30";
     private const string ExpectedFirstLine = "first";
     private const string ExpectedSecondLine = "second";
     private const int SmallOutputLimitCharacters = 64;
@@ -808,6 +812,51 @@ public async Task DefaultProcessRunner_NonZeroExitWithCompletedBrokenPipeKeepsCo
         }
     }
 
+    [Test]
+    public async Task DefaultProcessRunner_ZeroExitAfterClosingInputRemainsAnInputFailure()
+    {
+        var prompt = new string(PromptCharacter, DuplexPromptCharacters);
+        var invocation = CreateOutputInvocation(
+            OperatingSystem.IsWindows() ? WindowsZeroExitAfterClosingInputCommand : PosixZeroExitAfterClosingInputCommand,
+            TimeSpan.FromSeconds(5), DuplexMaximumProcessOutputCharacters) with
+        { Input = prompt };
+        var action = async () =>
+        {
+            await foreach (var _ in new DefaultCodexProcessRunner().RunAsync(invocation, NullLogger.Instance, CancellationToken.None))
+            {
+            }
+        };
+
+        var exception = await Assert.That(action).ThrowsException();
+
+        await Assert.That(exception).IsTypeOf<IOException>();
+        await Assert.That(exception).IsNotTypeOf<CliExecutionFailureException>();
+    }
+
+    [Test]
+    public async Task DefaultProcessRunner_StillRunningAfterClosingInputIsBoundedAndUnconfirmed()
+    {
+        var prompt = new string(PromptCharacter, DuplexPromptCharacters);
+        var invocation = CreateOutputInvocation(
+            OperatingSystem.IsWindows() ? WindowsStaysRunningAfterClosingInputCommand : PosixStaysRunningAfterClosingInputCommand,
+            TimeSpan.FromMilliseconds(250), DuplexMaximumProcessOutputCharacters) with
+        { Input = prompt };
+        var stopwatch = Stopwatch.StartNew();
+        var action = async () =>
+        {
+            await foreach (var _ in new DefaultCodexProcessRunner().RunAsync(invocation, NullLogger.Instance, CancellationToken.None))
+            {
+            }
+        };
+
+        var exception = await Assert.That(action).ThrowsException();
+        stopwatch.Stop();
+
+        await Assert.That(exception).IsTypeOf<TimeoutException>();
+        await Assert.That(exception).IsNotTypeOf<CliExecutionFailureException>();
+        await Assert.That(stopwatch.Elapsed < TimeSpan.FromSeconds(3)).IsTrue();
+    }
+
     [Test]
     public async Task DefaultProcessRunner_CancellationWhileProcessStillRunning_ThrowsOperationCanceledException()
     {

CodexSharpSDK/Execution/CodexExec.cs

@@ -1005,6 +1005,22 @@ private static async Task AwaitStandardInputWriteAsync(
 
             throw;
         }
+        catch (IOException) when (standardInputWriteTask.IsFaulted &&
+                                  standardInputWriteTask.Exception?.GetBaseException() is IOException)
+        {
+            await process.WaitForExitAsync(CancellationToken.None)
+                .WaitAsync(invocation.ProcessTerminationTimeout, CancellationToken.None)
+                .ConfigureAwait(false);
+            var capturedStandardError = await ReadStandardErrorAsync(standardErrorTask, invocation.ProcessTerminationTimeout)
+                .ConfigureAwait(false);
+            if (process.ExitCode != 0)
+            {
+                throw CliExecutionFailureException.FromProcessExit(process.ExitCode,
+                    $"Codex Exec exited with code {process.ExitCode}: {capturedStandardError.Text}");
+            }
+
+            throw;
+        }
         catch (Exception) when (process.HasExited)
         {
             await process.WaitForExitAsync(CancellationToken.None)