From da7942457331193dee5b0d7ae11925ebd5670c16 Mon Sep 17 00:00:00 2001
From: Claude <noreply@anthropic.com>
Date: Fri, 29 May 2026 05:34:29 +0000
Subject: [PATCH] Fix metadata commit failing when files are identical

The metadata update checked HasUncommittedChangesAsync (git status
--porcelain) before committing, which reports changes across the entire
working tree rather than only the staged metadata files. If the generated
metadata files were identical to what was already committed (nothing
staged) but some unrelated change existed in the working tree, the check
returned true and 'git commit' ran with nothing staged, failing with
"nothing to commit" and erroring the whole process.

Add IGitService.HasStagedChangesAsync (git diff --cached --name-only) and
use it after staging so we only commit when the staged metadata files
actually changed.
---
 KtsuBuild.Tests/Metadata/MetadataServiceTests.cs |  3 +++
 KtsuBuild/Abstractions/IGitService.cs            |  8 ++++++++
 KtsuBuild/Git/GitService.cs                      | 10 ++++++++++
 KtsuBuild/Metadata/MetadataService.cs            |  5 ++++-
 4 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/KtsuBuild.Tests/Metadata/MetadataServiceTests.cs b/KtsuBuild.Tests/Metadata/MetadataServiceTests.cs
index 933fffe..ad081fc 100644
--- a/KtsuBuild.Tests/Metadata/MetadataServiceTests.cs
+++ b/KtsuBuild.Tests/Metadata/MetadataServiceTests.cs
@@ -229,6 +229,9 @@ public Task PushAsync(string workingDirectory, CancellationToken cancellationTok
 		public Task<bool> HasUncommittedChangesAsync(string workingDirectory, CancellationToken cancellationToken = default)
 			=> Task.FromResult(false);
 
+		public Task<bool> HasStagedChangesAsync(string workingDirectory, CancellationToken cancellationToken = default)
+			=> Task.FromResult(false);
+
 		public Task SetIdentityAsync(string workingDirectory, string name, string email, CancellationToken cancellationToken = default)
 			=> Task.CompletedTask;
 	}
diff --git a/KtsuBuild/Abstractions/IGitService.cs b/KtsuBuild/Abstractions/IGitService.cs
index 731d247..bff3389 100644
--- a/KtsuBuild/Abstractions/IGitService.cs
+++ b/KtsuBuild/Abstractions/IGitService.cs
@@ -140,6 +140,14 @@ public interface IGitService
 	/// <returns>True if there are uncommitted changes.</returns>
 	public Task<bool> HasUncommittedChangesAsync(string workingDirectory, CancellationToken cancellationToken = default);
 
+	/// <summary>
+	/// Checks if there are staged changes ready to be committed.
+	/// </summary>
+	/// <param name="workingDirectory">The repository directory.</param>
+	/// <param name="cancellationToken">A cancellation token.</param>
+	/// <returns>True if there are staged changes.</returns>
+	public Task<bool> HasStagedChangesAsync(string workingDirectory, CancellationToken cancellationToken = default);
+
 	/// <summary>
 	/// Sets the git user identity for commits.
 	/// </summary>
diff --git a/KtsuBuild/Git/GitService.cs b/KtsuBuild/Git/GitService.cs
index 4e2f965..049c724 100644
--- a/KtsuBuild/Git/GitService.cs
+++ b/KtsuBuild/Git/GitService.cs
@@ -221,6 +221,16 @@ public async Task<bool> HasUncommittedChangesAsync(string workingDirectory, Canc
 		return !string.IsNullOrWhiteSpace(result.StandardOutput);
 	}
 
+	/// <inheritdoc/>
+	public async Task<bool> HasStagedChangesAsync(string workingDirectory, CancellationToken cancellationToken = default)
+	{
+		Ensure.NotNull(workingDirectory);
+		// --cached limits the diff to staged changes, which is exactly what `git commit` would commit.
+		// --name-only keeps the output empty when nothing is staged so we can detect a no-op commit.
+		ProcessResult result = await processRunner.RunAsync("git", "diff --cached --name-only", workingDirectory, cancellationToken).ConfigureAwait(false);
+		return !string.IsNullOrWhiteSpace(result.StandardOutput);
+	}
+
 	/// <inheritdoc/>
 	public async Task SetIdentityAsync(string workingDirectory, string name, string email, CancellationToken cancellationToken = default)
 	{
diff --git a/KtsuBuild/Metadata/MetadataService.cs b/KtsuBuild/Metadata/MetadataService.cs
index c5ac738..17ccfee 100644
--- a/KtsuBuild/Metadata/MetadataService.cs
+++ b/KtsuBuild/Metadata/MetadataService.cs
@@ -93,7 +93,10 @@ public async Task<MetadataUpdateResult> UpdateAllAsync(MetadataUpdateOptions opt
 				logger.WriteInfo($"Adding files to git: {string.Join(", ", filesToAdd)}");
 				await gitService.StageFilesAsync(config.WorkspacePath, filesToAdd, cancellationToken).ConfigureAwait(false);
 
-				hasChanges = await gitService.HasUncommittedChangesAsync(config.WorkspacePath, cancellationToken).ConfigureAwait(false);
+				// Only the staged metadata files are committed, so check for staged changes specifically.
+				// If the generated files are identical to what's already committed, nothing is staged
+				// and committing would fail with "nothing to commit", erroring the whole process.
+				hasChanges = await gitService.HasStagedChangesAsync(config.WorkspacePath, cancellationToken).ConfigureAwait(false);
 
 				if (hasChanges)
 				{