Handle FileNotFoundException when generating the CoA extraction mod (#2944) #patch

Sentry event ID: 75489e34df5b47c896a9a5416fe41843

Author: IhateTrains

ImperatorToCK3.UnitTests/CommonUtils/FileHelperTests.cs

@@ -0,0 +1,80 @@
+using System;
+using System.IO;
+using Xunit;
+using ImperatorToCK3.CommonUtils;
+using commonItems.Mods;
+using ImperatorToCK3.Imperator;
+using commonItems.Exceptions;
+
+namespace ImperatorToCK3.UnitTests.CommonUtils {
+	public class FileHelperTests : IDisposable {
+		private readonly string tempRoot;
+
+		public FileHelperTests() {
+			tempRoot = Path.Combine(Path.GetTempPath(), "IRToCK3Tests", Guid.NewGuid().ToString());
+			Directory.CreateDirectory(tempRoot);
+		}
+
+		public void Dispose() {
+			try {
+				Directory.Delete(tempRoot, recursive: true);
+			} catch { /* best effort cleanup */ }
+		}
+
+		[Fact]
+		public void EnsureDirectoryExists_createsMissingPath() {
+			var target = Path.Combine(tempRoot, "a", "b", "c");
+			Assert.False(Directory.Exists(target));
+
+			FileHelper.EnsureDirectoryExists(target);
+
+			Assert.True(Directory.Exists(target));
+		}
+
+		[Fact]
+		public void EnsureDirectoryExists_throwsWhenFileCollision() {
+			var target = Path.Combine(tempRoot, "collisionDir");
+			Directory.CreateDirectory(Path.GetDirectoryName(target)!);
+			File.WriteAllText(target, "oops");
+			Assert.True(File.Exists(target));
+
+			var ex = Assert.Throws<UserErrorException>(() => FileHelper.EnsureDirectoryExists(target));
+			Assert.Contains("directory", ex.Message, StringComparison.OrdinalIgnoreCase);
+
+			// original file must remain untouched
+			Assert.True(File.Exists(target));
+			Assert.False(Directory.Exists(target));
+		}
+
+		[Fact]
+		public void OutputGuiContainer_handlesFileInPlaceOfGuiDirectory() {
+			// prepare a fake Imperator installation with one GUI file
+			var gameRoot = Path.Combine(tempRoot, "game");
+			var guiDir = Path.Combine(gameRoot, "gui");
+			Directory.CreateDirectory(guiDir);
+			var topbar = Path.Combine(guiDir, "ingame_topbar.gui");
+			File.WriteAllText(topbar, "foo");
+
+			var modFS = new ModFilesystem(gameRoot, []);
+
+			// configuration points to a separate doc path; create a collision file
+			var docPath = Path.Combine(tempRoot, "docs");
+			var config = new Configuration {
+				ImperatorDocPath = docPath
+			};
+			Directory.CreateDirectory(docPath);
+
+			var collisionFile = Path.Combine(docPath, "mod", "coa_export_mod", "gui");
+			Directory.CreateDirectory(Path.GetDirectoryName(collisionFile)!);
+			File.WriteAllText(collisionFile, "not a directory");
+
+			// run the helper; it should not crash but will bail out early
+			World.OutputGuiContainer(modFS, [], config);
+
+			// collision file remains and no directory has been created
+			var expectedGuiDir = Path.Combine(docPath, "mod", "coa_export_mod", "gui");
+			Assert.False(Directory.Exists(expectedGuiDir));
+			Assert.True(File.Exists(collisionFile));
+		}
+	}
+}

ImperatorToCK3/CommonUtils/FileHelper.cs

@@ -1,8 +1,9 @@
-using commonItems.Exceptions;
+
 
 namespace ImperatorToCK3.CommonUtils;
 
 using commonItems;
+using commonItems.Exceptions;
 using System;
 using Polly;
 using System.IO;
@@ -69,7 +70,48 @@ public static void DeleteWithRetries(string filePath) {
 			throw new UserErrorException($"Failed to delete \"{filePath}\". {CloseProgramsHint}");
 		}
 	}
-	
+
+	// Ensures that the given directory path exists. If a file exists with the
+	// same name as the desired directory it will be removed first. The method
+	// retries the creation when a sharing violation occurs, much like the
+	// other helpers in this class. This helps mitigate cases where a transient
+	// lock or a stray file prevents folder creation.
+	public static void EnsureDirectoryExists(string directoryPath) {
+		if (string.IsNullOrEmpty(directoryPath)) {
+			return;
+		}
+
+		// if the path already exists as a directory we're done
+		if (Directory.Exists(directoryPath)) {
+			return;
+		}
+
+		// if a file exists where we'd like a directory, bail out rather than
+		// attempting to delete it.
+		if (File.Exists(directoryPath)) {
+			throw new UserErrorException(
+				$"Cannot create directory \"{directoryPath}\" because a file with the same name already exists.");
+		}
+
+		const int maxAttempts = 10;
+		int currentAttempt = 0;
+		var policy = Policy
+			.Handle<IOException>(IsFilesSharingViolation)
+			.WaitAndRetry(maxAttempts,
+				sleepDurationProvider: _ => TimeSpan.FromSeconds(1),
+				onRetry: (_, _, _) => {
+				currentAttempt++;
+				Logger.Warn($"Attempt {currentAttempt} to create directory \"{directoryPath}\" failed.");
+			});
+
+		try {
+			policy.Execute(() => Directory.CreateDirectory(directoryPath));
+		} catch (IOException ex) when (IsFilesSharingViolation(ex)) {
+			Logger.Debug(ex.ToString());
+			throw new UserErrorException($"Failed to create directory \"{directoryPath}\". {CloseProgramsHint}");
+		}
+	}
+
 	public static void MoveWithRetries(string sourceFilePath, string destFilePath) {
 		const int maxAttempts = 10;
 

ImperatorToCK3/Imperator/World.cs

@@ -91,39 +91,51 @@ protected World(Configuration config) {
 
 		diplomacyDB = new();
 	}
-	
-	private static void OutputGuiContainer(ModFilesystem modFS, IEnumerable<string> tagsNeedingFlags, Configuration config) {
+
+	internal static void OutputGuiContainer(ModFilesystem modFS, IEnumerable<string> tagsNeedingFlags, Configuration config) {
 		Logger.Debug("Modifying gui for exporting CoAs...");
-		
+
 		const string relativeTopBarGuiPath = "gui/ingame_topbar.gui";
 		var topBarGuiPath = modFS.GetActualFileLocation(relativeTopBarGuiPath);
 		if (topBarGuiPath is null) {
 			Logger.Warn($"{relativeTopBarGuiPath} not found, can't write CoA export commands!");
 			return;
 		}
 
+		// build the GUI snippet we want to insert
 		var guiTextBuilder = new StringBuilder();
 		guiTextBuilder.AppendLine("\tstate = {");
 		guiTextBuilder.AppendLine("\t\tname = _show");
 		string commandsString = string.Join(';', tagsNeedingFlags.Select(tag => $"coat_of_arms {tag}"));
 		commandsString += ";dumpdatatypes"; // This will let us know when the commands finished executing.
 		guiTextBuilder.AppendLine($"\t\ton_start=\"[ExecuteConsoleCommandsForced('{commandsString}')]\"");
 		guiTextBuilder.AppendLine("\t}");
-		
+
 		List<string> lines = [.. File.ReadAllLines(topBarGuiPath)];
 		int index = lines.FindIndex(line => line.Contains("name = \"ingame_topbar\""));
 		if (index != -1) {
 			lines.Insert(index + 1, guiTextBuilder.ToString());
 		}
 
-		var topBarOutputPath = Path.Combine(config.ImperatorDocPath, "mod/coa_export_mod", relativeTopBarGuiPath);
-		Logger.Debug($"Writing modified GUI to \"{topBarOutputPath}\"...");
-		var topBarOutputDir = Path.GetDirectoryName(topBarOutputPath);
-		if (topBarOutputDir is not null) {
-			Directory.CreateDirectory(topBarOutputDir);
+		// attempt to write the modified GUI
+		try {
+			var topBarOutputPath = Path.Combine(config.ImperatorDocPath, "mod/coa_export_mod", relativeTopBarGuiPath);
+			Logger.Debug($"Writing modified GUI to \"{topBarOutputPath}\"...");
+			var topBarOutputDir = Path.GetDirectoryName(topBarOutputPath);
+			if (topBarOutputDir is not null) {
+				FileHelper.EnsureDirectoryExists(topBarOutputDir);
+			}
+
+			using var writer = FileHelper.OpenWriteWithRetries(topBarOutputPath, Encoding.UTF8);
+			foreach (var line in lines) {
+				writer.WriteLine(line);
+			}
+		} catch (Exception e) {
+			Logger.Warn($"Failed to output modified GUI: {e.Message}");
+			// bail out but don't crash the whole conversion
+			return;
 		}
-		File.WriteAllLines(topBarOutputPath, lines);
-		
+
 		// Create a .mod file for the temporary mod.
 		Logger.Debug("Creating temporary mod file...");
 		string modFileContents =