Add error logging to slash command preparation

Signed-off-by: Octol1ttle <l1ttleofficial@outlook.com>

Boyfriend.cs

@@ -69,6 +69,7 @@ public class Boyfriend {
                     services.AddTransient<IConfigurationBuilder, ConfigurationBuilder>()
                         .AddDiscordCaching()
                         .AddDiscordCommands(true)
+                        .AddPreparationErrorEvent<ErrorLoggingPreparationErrorEvent>()
                         .AddPostExecutionEvent<ErrorLoggingPostExecutionEvent>()
                         .AddInteractivity()
                         .AddInteractionGroup<InteractionResponders>()

Commands/ErrorLoggingPostExecutionEvent.cs

@@ -1,35 +0,0 @@
-using Microsoft.Extensions.Logging;
-using Remora.Discord.Commands.Contexts;
-using Remora.Discord.Commands.Services;
-using Remora.Results;
-
-// ReSharper disable ClassNeverInstantiated.Global
-
-namespace Boyfriend.Commands;
-
-/// <summary>
-///     Handles error logging for slash command groups.
-/// </summary>
-public class ErrorLoggingPostExecutionEvent : IPostExecutionEvent {
-    private readonly ILogger<ErrorLoggingPostExecutionEvent> _logger;
-
-    public ErrorLoggingPostExecutionEvent(ILogger<ErrorLoggingPostExecutionEvent> logger) {
-        _logger = logger;
-    }
-
-    /// <summary>
-    ///     Logs a warning using the injected <see cref="ILogger" /> if the <paramref name="commandResult" /> has not
-    ///     succeeded.
-    /// </summary>
-    /// <param name="context">The context of the slash command. Unused.</param>
-    /// <param name="commandResult">The result whose success is checked.</param>
-    /// <param name="ct">The cancellation token for this operation. Unused.</param>
-    /// <returns>A result which has succeeded.</returns>
-    public Task<Result> AfterExecutionAsync(
-        ICommandContext context, IResult commandResult, CancellationToken ct = default) {
-        if (!commandResult.IsSuccess)
-            _logger.LogWarning("Error in slash command handler.\n{ErrorMessage}", commandResult.Error.Message);
-
-        return Task.FromResult(Result.FromSuccess());
-    }
-}

Commands/ErrorLoggingPreparationErrorEvent.cs

@@ -0,0 +1,62 @@
+using Microsoft.Extensions.Logging;
+using Remora.Discord.Commands.Contexts;
+using Remora.Discord.Commands.Services;
+using Remora.Results;
+
+// ReSharper disable ClassNeverInstantiated.Global
+
+namespace Boyfriend.Commands;
+
+/// <summary>
+///     Handles error logging for slash commands that couldn't be successfully prepared.
+/// </summary>
+public class ErrorLoggingPreparationErrorEvent : IPreparationErrorEvent {
+    private readonly ILogger<ErrorLoggingPreparationErrorEvent> _logger;
+
+    public ErrorLoggingPreparationErrorEvent(ILogger<ErrorLoggingPreparationErrorEvent> logger) {
+        _logger = logger;
+    }
+
+    /// <summary>
+    ///     Logs a warning using the injected <see cref="ILogger" /> if the <paramref name="preparationResult" /> has not
+    ///     succeeded.
+    /// </summary>
+    /// <param name="context">The context of the slash command. Unused.</param>
+    /// <param name="preparationResult">The result whose success is checked.</param>
+    /// <param name="ct">The cancellation token for this operation. Unused.</param>
+    /// <returns>A result which has succeeded.</returns>
+    public Task<Result> PreparationFailed(
+        IOperationContext context, IResult preparationResult, CancellationToken ct = default) {
+        if (!preparationResult.IsSuccess)
+            _logger.LogWarning("Error in slash command preparation.\n{ErrorMessage}", preparationResult.Error.Message);
+
+        return Task.FromResult(Result.FromSuccess());
+    }
+}
+
+/// <summary>
+///     Handles error logging for slash command groups.
+/// </summary>
+public class ErrorLoggingPostExecutionEvent : IPostExecutionEvent {
+    private readonly ILogger<ErrorLoggingPostExecutionEvent> _logger;
+
+    public ErrorLoggingPostExecutionEvent(ILogger<ErrorLoggingPostExecutionEvent> logger) {
+        _logger = logger;
+    }
+
+    /// <summary>
+    ///     Logs a warning using the injected <see cref="ILogger" /> if the <paramref name="commandResult" /> has not
+    ///     succeeded.
+    /// </summary>
+    /// <param name="context">The context of the slash command. Unused.</param>
+    /// <param name="commandResult">The result whose success is checked.</param>
+    /// <param name="ct">The cancellation token for this operation. Unused.</param>
+    /// <returns>A result which has succeeded.</returns>
+    public Task<Result> AfterExecutionAsync(
+        ICommandContext context, IResult commandResult, CancellationToken ct = default) {
+        if (!commandResult.IsSuccess)
+            _logger.LogWarning("Error in slash command execution.\n{ErrorMessage}", commandResult.Error.Message);
+
+        return Task.FromResult(Result.FromSuccess());
+    }
+}