Fix file lock not getting disposed when postamble throws an exception

DiscordChatExporter.Cli.Tests/Fixtures/ExportWrapperFixture.cs

@@ -34,13 +34,22 @@ public class ExportWrapperFixture : IDisposable
         // Perform export only if it hasn't been done before
         if (!File.Exists(filePath))
         {
-            await new ExportChannelsCommand
+            try
             {
-                Token = Secrets.DiscordToken,
-                ChannelIds = new[] { channelId },
-                ExportFormat = format,
-                OutputPath = filePath
-            }.ExecuteAsync(new FakeConsole());
+                await new ExportChannelsCommand
+                {
+                    Token = Secrets.DiscordToken,
+                    ChannelIds = new[] { channelId },
+                    ExportFormat = format,
+                    OutputPath = filePath
+                }.ExecuteAsync(new FakeConsole());
+            }
+            catch
+            {
+                // If the export fails, delete the file to prevent it from being used by tests
+                File.Delete(filePath);
+                throw;
+            }
         }
 
         return await File.ReadAllTextAsync(filePath);

DiscordChatExporter.Core/Exporting/MessageExporter.cs

@@ -23,9 +23,16 @@ internal partial class MessageExporter : IAsyncDisposable
     {
         if (_writer is not null)
         {
-            await _writer.WritePostambleAsync(cancellationToken);
-            await _writer.DisposeAsync();
-            _writer = null;
+            try
+            {
+                await _writer.WritePostambleAsync(cancellationToken);
+            }
+            // Writer must be disposed, even if writing postamble fails
+            finally
+            {
+                await _writer.DisposeAsync();
+                _writer = null;
+            }
         }
     }
 

DiscordChatExporter.Core/Exporting/Writers/HtmlMessageWriter.cs

@@ -67,9 +67,7 @@ internal class HtmlMessageWriter : MessageWriter
     }
 
     // Use <!--wmm:ignore--> to preserve blocks of code inside the templates
-    private string Minify(string html) => _minifier
-        .Minify(html, false)
-        .MinifiedContent;
+    private string Minify(string html) => _minifier.Minify(html, false).MinifiedContent;
 
     public override async ValueTask WritePreambleAsync(
         CancellationToken cancellationToken = default)