Added new "GetMethodInfo" and "GetPropertyInfo" methods to the "Refle…

…ctionUtils" class

The methods allows getting either method info or property info of an expression.

src/Skybrud.Essentials/Reflection/ReflectionUtils.cs

@@ -2,6 +2,7 @@
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
+using System.Linq.Expressions;
 using System.Reflection;
 using System.Runtime.CompilerServices;
 using Skybrud.Essentials.Collections;
@@ -542,6 +543,44 @@ public static bool IsExtensionMethod(MethodInfo? method) {
 
 #endif
 
+        /// <summary>
+        /// Returns the <see cref="MethodInfo"/> identified by the specified <paramref name="expression"/>.
+        /// </summary>
+        /// <typeparam name="T">The type of the expression.</typeparam>
+        /// <param name="expression">The expression.</param>
+        /// <returns>An instance of <see cref="MethodInfo"/>.</returns>
+        /// <exception cref="ArgumentException">If <paramref name="expression"/> is not a method expression.</exception>
+        public static MethodInfo GetMethodInfo<T>(Expression<T> expression) {
+
+            if (expression.Body is not MethodCallExpression methodExpression) {
+                throw new ArgumentException($"Expression body is not of type MethodCallExpression: {expression}");
+            }
+
+            return methodExpression.Method;
+
+        }
+
+        /// <summary>
+        /// Returns the <see cref="PropertyInfo"/> identified by the specified <paramref name="expression"/>.
+        /// </summary>
+        /// <typeparam name="T">The type of the expression.</typeparam>
+        /// <param name="expression">The expression.</param>
+        /// <returns>An instance of <see cref="PropertyInfo"/>.</returns>
+        /// <exception cref="ArgumentException">If <paramref name="expression"/> is not a property expression.</exception>
+        public static PropertyInfo GetPropertyInfo<T>(Expression<T> expression) {
+
+            if (expression.Body is not MemberExpression member) {
+                throw new ArgumentException($"Expression body is not of type MemberExpression: {expression}");
+            }
+
+            if (member.Member is not PropertyInfo propertyInfo) {
+                throw new ArgumentException($"Expression member is not a property: {expression}");
+            }
+
+            return propertyInfo;
+
+        }
+
     }
 
 }

src/TestProject1/ReflectionTests.cs

@@ -0,0 +1,47 @@
+using System.Linq.Expressions;
+using Skybrud.Essentials.Reflection;
+
+namespace TestProject1 {
+
+    [TestClass]
+    public class ReflectionTests {
+
+        [TestMethod]
+        public void GetMethodInfo() {
+
+            Expression<Func<MyModel, string>> expression = GetExpression<MyModel, string>(x => x.MyMethod());
+
+            var method = ReflectionUtils.GetMethodInfo(expression);
+
+            Assert.AreEqual("MyMethod", method.Name);
+
+        }
+
+        [TestMethod]
+        public void GetPropertyInfo() {
+
+            Expression<Func<MyModel, string>> expression = GetExpression<MyModel, string>(x => x.MyProperty);
+
+            var property = ReflectionUtils.GetPropertyInfo(expression);
+
+            Assert.AreEqual("MyProperty", property.Name);
+
+        }
+
+        private Expression<Func<TModel, TProperty>> GetExpression<TModel, TProperty>(Expression<Func<TModel, TProperty>> expression) {
+            return expression;
+        }
+
+        public class MyModel {
+
+            public string MyProperty { get; set; } = "Hello There";
+
+            public string MyMethod() {
+                return "Hello Where";
+            }
+
+        }
+
+    }
+
+}