Handle in-progress file change parser status

Author: KSemenenko

GeminiSharpSDK.Tests/Performance/ThreadEventParserPerformanceTests.cs

@@ -17,6 +17,7 @@ public class ThreadEventParserPerformanceTests
         """{"type":"result","status":"success","stats":{"input_tokens":10,"cached":3,"output_tokens":5}}""",
         """{"type":"thread.started","thread_id":"legacy_thread"}""",
         """{"type":"turn.failed","error":{"message":"legacy failed"}}""",
+        """{"type":"item.started","item":{"id":"file_1","type":"file_change","changes":[{"path":"src/app.cs","kind":"update"}],"status":"in_progress"}}""",
         """{"type":"item.completed","item":{"id":"agent_1","type":"agent_message","text":"legacy text"}}""",
     ];
 
@@ -70,6 +71,7 @@ public async Task Parse_MixedSupportedEventStream_CompletesWithinBudgetAndCovers
         await Assert.That(eventKinds).Contains(typeof(ResultEvent).FullName!);
         await Assert.That(eventKinds).Contains(typeof(ThreadStartedEvent).FullName!);
         await Assert.That(eventKinds).Contains(typeof(TurnFailedEvent).FullName!);
+        await Assert.That(eventKinds).Contains(typeof(ItemStartedEvent).FullName!);
         await Assert.That(eventKinds).Contains(typeof(ItemCompletedEvent).FullName!);
         await Assert.That(toolResultStatuses).IsEquivalentTo([ToolResultStatus.Success]);
         await Assert.That(assistantMessages).IsGreaterThan(0);

GeminiSharpSDK.Tests/Unit/ThreadEventParserTests.cs

@@ -63,6 +63,21 @@ public async Task Parse_PreservesLegacyThreadStartedSupport()
         await Assert.That(parsed).IsTypeOf<ThreadStartedEvent>();
     }
 
+    [Test]
+    public async Task Parse_ParsesFileChangeItemStartedWithInProgressStatus()
+    {
+        var parsed = (ItemStartedEvent)ThreadEventParser.Parse(
+            "{\"type\":\"item.started\",\"item\":{\"id\":\"item_1\",\"type\":\"file_change\",\"changes\":[{\"path\":\"C:/git/GeminiSandbox/apple.txt\",\"kind\":\"add\"}],\"status\":\"in_progress\"}}");
+
+        await Assert.That(parsed.Item).IsTypeOf<FileChangeItem>();
+
+        var fileChange = (FileChangeItem)parsed.Item;
+        await Assert.That(fileChange.Status).IsEqualTo(PatchApplyStatus.InProgress);
+        await Assert.That(fileChange.Changes).Count().IsEqualTo(1);
+        await Assert.That(fileChange.Changes[0].Path).IsEqualTo("C:/git/GeminiSandbox/apple.txt");
+        await Assert.That(fileChange.Changes[0].Kind).IsEqualTo(PatchChangeKind.Add);
+    }
+
     [Test]
     public async Task Parse_ThrowsForUnsupportedEventType()
     {

GeminiSharpSDK/Internal/ThreadEventParser.cs

@@ -301,6 +301,7 @@ private static PatchApplyStatus ParsePatchApplyStatus(string status)
     {
         return status switch
         {
+            GeminiProtocolConstants.Statuses.InProgress => PatchApplyStatus.InProgress,
             GeminiProtocolConstants.Statuses.Completed => PatchApplyStatus.Completed,
             GeminiProtocolConstants.Statuses.Failed => PatchApplyStatus.Failed,
             _ => throw new InvalidOperationException($"Unsupported patch apply status: {status}"),

GeminiSharpSDK/Models/Items.cs

@@ -25,6 +25,7 @@ public enum PatchChangeKind
 
 public enum PatchApplyStatus
 {
+    InProgress,
     Completed,
     Failed,
 }

docs/Features/thread-run-flow.md

@@ -40,6 +40,7 @@ Provide deterministic thread-based execution over Gemini CLI so C# consumers can
 - Invalid JSONL event lines must fail fast with parse context.
 - Protocol tokens are parsed via constants, not inline literals.
 - Parser must support the current `init`, `message`, `tool_use`, `tool_result`, `error`, and `result` event envelope, while retaining compatibility with older persisted thread fixtures.
+- `file_change` items may surface before completion with `status=in_progress`; parser must accept in-progress, completed, and failed patch-apply states.
 - Optional `ILogger` (`Microsoft.Extensions.Logging`) receives process lifecycle diagnostics (start/success/failure/cancellation).
 - Structured output uses typed `StructuredOutputSchema` models that are embedded into the prompt contract and deserialized to typed DTOs; fenced JSON responses are normalized before deserialization.
 - `LocalImageInput` accepts image path, `FileInfo`, or `Stream`; stream inputs are materialized to temp files and referenced in the prompt as local `@path` inputs.