From ed714395093a8d359f1cb103daf0874c672d8e92 Mon Sep 17 00:00:00 2001
From: Zingabopp <Zingabopp@gmail.com>
Date: Sat, 4 Jan 2020 12:12:30 -0600
Subject: [PATCH] Updated ReflectionUtil

Added null checks for the GetField/Property/Method that throws an InvalidOperationException with an informative message. This does change the fail silently behavior it had before, but it would probably be better to know right away if it's failing.
---
 IPA.Loader/Utilities/ReflectionUtil.cs | 79 ++++++++++++++++++++------
 1 file changed, 62 insertions(+), 17 deletions(-)

diff --git a/IPA.Loader/Utilities/ReflectionUtil.cs b/IPA.Loader/Utilities/ReflectionUtil.cs
index 922be878..e5b0650e 100644
--- a/IPA.Loader/Utilities/ReflectionUtil.cs
+++ b/IPA.Loader/Utilities/ReflectionUtil.cs
@@ -15,12 +15,30 @@ namespace IPA.Utilities
         /// <param name="obj">the object instance</param>
         /// <param name="fieldName">the field to set</param>
         /// <param name="value">the value to set it to</param>
+        /// <exception cref="InvalidOperationException">thrown when <paramref name="fieldName"/> is not a member of <paramref name="obj"/></exception>
 		public static void SetPrivateField(this object obj, string fieldName, object value)
 		{
-			var prop = obj.GetType().GetField(fieldName, BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Instance);
-			prop?.SetValue(obj, value);
+            Type targetType = obj.GetType();
+            obj.SetPrivateField(fieldName, value, targetType);
 		}
-		
+
+        /// <summary>
+        /// Sets a (potentially) private field on the target object. <paramref name="targetType"/> specifies the <see cref="Type"/> the field belongs to. 
+        /// </summary>
+        /// <param name="obj">the object instance</param>
+        /// <param name="fieldName">the field to set</param>
+        /// <param name="value">the value to set it to</param>
+        /// <param name="targetType">the object type the field belongs to</param>
+        /// <exception cref="InvalidOperationException">thrown when <paramref name="fieldName"/> is not a member of <paramref name="obj"/></exception>
+        /// <exception cref="ArgumentException">thrown when <paramref name="obj"/> isn't assignable as <paramref name="targetType"/></exception>
+		public static void SetPrivateField(this object obj, string fieldName, object value, Type targetType)
+        {
+            var prop = targetType.GetField(fieldName, BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Instance);
+            if (prop == null)
+                throw new InvalidOperationException($"{fieldName} is not a member of {targetType.Name}");
+            prop.SetValue(obj, value);
+        }
+
         /// <summary>
         /// Gets the value of a (potentially) private field.
         /// </summary>
@@ -28,24 +46,47 @@ namespace IPA.Utilities
         /// <param name="obj">the object instance to pull from</param>
         /// <param name="fieldName">the name of the field to read</param>
         /// <returns>the value of the field</returns>
-		public static T GetPrivateField<T>(this object obj, string fieldName)
-		{
-			var prop = obj.GetType().GetField(fieldName, BindingFlags.NonPublic | BindingFlags.Instance);
-			var value = prop?.GetValue(obj);
-			return (T) value;
+        /// <exception cref="InvalidOperationException">thrown when <paramref name="fieldName"/> is not a member of <paramref name="obj"/></exception>
+        public static T GetPrivateField<T>(this object obj, string fieldName)
+        {
+            Type targetType = obj.GetType();
+            return obj.GetPrivateField<T>(fieldName, targetType);
 		}
-		
+
+        /// <summary>
+        /// Gets the value of a (potentially) private field. <paramref name="targetType"/> specifies the <see cref="Type"/> the field belongs to
+        /// </summary>
+        /// <typeparam name="T">the type of the field (result casted)</typeparam>
+        /// <param name="obj">the object instance to pull from</param>
+        /// <param name="fieldName">the name of the field to read</param>
+        /// <param name="targetType">the object type the field belongs to</param>
+        /// <returns>the value of the field</returns>
+        /// <exception cref="InvalidOperationException">thrown when <paramref name="fieldName"/> is not a member of <paramref name="obj"/></exception>
+        /// <exception cref="ArgumentException">thrown when <paramref name="obj"/> isn't assignable as <paramref name="targetType"/></exception>
+        public static T GetPrivateField<T>(this object obj, string fieldName, Type targetType)
+        {
+            var prop = targetType.GetField(fieldName, BindingFlags.NonPublic | BindingFlags.Instance);
+            if (prop == null)
+                throw new InvalidOperationException($"{fieldName} is not a member of {targetType.Name}");
+            var value = prop.GetValue(obj);
+            return (T)value;
+        }
+
         /// <summary>
         /// Sets a (potentially) private property on the target object.
         /// </summary>
         /// <param name="obj">the target object instance</param>
         /// <param name="propertyName">the name of the property</param>
         /// <param name="value">the value to set it to</param>
-		public static void SetPrivateProperty(this object obj, string propertyName, object value)
-		{
-			var prop = obj.GetType()
-				.GetProperty(propertyName, BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Instance);
-			prop?.SetValue(obj, value, null);
+        /// <exception cref="InvalidOperationException">thrown when <paramref name="propertyName"/> is not a member of <paramref name="obj"/></exception>
+        public static void SetPrivateProperty(this object obj, string propertyName, object value)
+        {
+            Type targetType = obj.GetType();
+            var prop = targetType
+                .GetProperty(propertyName, BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Instance);
+            if (prop == null)
+                throw new InvalidOperationException($"{propertyName} is not a member of {targetType.Name}");
+            prop.SetValue(obj, value, null);
 		}
 
         /// <summary>
@@ -55,10 +96,14 @@ namespace IPA.Utilities
         /// <param name="methodName">the method name</param>
         /// <param name="methodParams">the method parameters</param>
         /// <returns>the return value</returns>
+        /// <exception cref="InvalidOperationException">thrown when <paramref name="methodName"/> is not a member of <paramref name="obj"/></exception>
 		public static object InvokePrivateMethod(this object obj, string methodName, params object[] methodParams)
-		{
-			MethodInfo dynMethod = obj.GetType().GetMethod(methodName, BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Instance);
-			return dynMethod?.Invoke(obj, methodParams);
+        {
+            Type targetType = obj.GetType();
+            MethodInfo dynMethod = targetType.GetMethod(methodName, BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Instance);
+            if (dynMethod == null)
+                throw new InvalidOperationException($"{methodName} is not a member of {targetType.Name}");
+            return dynMethod.Invoke(obj, methodParams);
 		}
 
         /// <summary>