1 files changed, 75 insertions, 0 deletions
diff --git a/src/SMAPI.Mods.ErrorHandler/Patches/DictionaryPatcher.cs b/src/SMAPI.Mods.ErrorHandler/Patches/DictionaryPatcher.cs
new file mode 100644
index 00000000..6ad64e16
--- /dev/null
+++ b/src/SMAPI.Mods.ErrorHandler/Patches/DictionaryPatcher.cs
@@ -0,0 +1,75 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+using HarmonyLib;
+using StardewModdingAPI.Internal.Patching;
+using StardewValley.GameData;
+using StardewValley.GameData.HomeRenovations;
+using StardewValley.GameData.Movies;
+
+namespace StardewModdingAPI.Mods.ErrorHandler.Patches
+{
+    /// <summary>Harmony patches for <see cref="Dictionary{TKey,TValue}"/> which add the accessed key to <see cref="KeyNotFoundException"/> exceptions.</summary>
+    /// <remarks>Patch methods must be static for Harmony to work correctly. See the Harmony documentation before renaming patch arguments.</remarks>
+    [SuppressMessage("ReSharper", "InconsistentNaming", Justification = "Argument names are defined by Harmony and methods are named for clarity.")]
+    [SuppressMessage("ReSharper", "IdentifierTypo", Justification = "Argument names are defined by Harmony and methods are named for clarity.")]
+    internal class DictionaryPatcher : BasePatcher
+    {
+        /*********
+        ** Fields
+        *********/
+        /// <summary>Simplifies access to private code.</summary>
+        private static IReflectionHelper Reflection;
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        /// <param name="reflector">Simplifies access to private code.</param>
+        public DictionaryPatcher(IReflectionHelper reflector)
+        {
+            DictionaryPatcher.Reflection = reflector;
+        }
+
+        /// <inheritdoc />
+        public override void Apply(Harmony harmony, IMonitor monitor)
+        {
+            Type[] keyTypes = { typeof(int), typeof(string) };
+            Type[] valueTypes = { typeof(int), typeof(string), typeof(HomeRenovation), typeof(MovieData), typeof(SpecialOrderData) };
+
+            foreach (Type keyType in keyTypes)
+            {
+                foreach (Type valueType in valueTypes)
+                {
+                    Type dictionaryType = typeof(Dictionary<,>).MakeGenericType(keyType, valueType);
+
+                    harmony.Patch(
+                        original: AccessTools.Method(dictionaryType, "get_Item") ?? throw new InvalidOperationException($"Can't find method {PatchHelper.GetMethodString(dictionaryType, "get_Item")} to patch."),
+                        finalizer: this.GetHarmonyMethod(nameof(DictionaryPatcher.Finalize_GetItem))
+                    );
+                }
+            }
+        }
+
+
+        /*********
+        ** Private methods
+        *********/
+        /// <summary>The method to call after the dictionary indexer throws an exception.</summary>
+        /// <param name="key">The dictionary key being fetched.</param>
+        /// <param name="__exception">The exception thrown by the wrapped method, if any.</param>
+        /// <returns>Returns the exception to throw, if any.</returns>
+        private static Exception Finalize_GetItem(object key, Exception __exception)
+        {
+            if (__exception is KeyNotFoundException)
+            {
+                DictionaryPatcher.Reflection
+                    .GetField<string>(__exception, "_message")
+                    .SetValue($"{__exception.Message}\nkey: '{key}'");
+            }
+
+            return __exception;
+        }
+    }
+}