Fix metadata commit failing when files are identical

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;
 	}

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>

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)
 	{

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)
 				{