From db5749b4747ab3ef7e7ab7d4b78f7385b9329031 Mon Sep 17 00:00:00 2001
From: Martin Smith <martinsmith1968@gmail.com>
Date: Thu, 29 Aug 2024 19:22:34 +0100
Subject: [PATCH] stash

---
 .../Reflection/ExpressionExtensions.cs        | 148 ++++++++++++++++++
 .../Reflection/ExpressionExtensionsTests.cs   |  59 +++++++
 2 files changed, 207 insertions(+)
 create mode 100644 src/DNX.Extensions/Reflection/ExpressionExtensions.cs
 create mode 100644 tests/DNX.Extensions.Tests/Reflection/ExpressionExtensionsTests.cs

diff --git a/src/DNX.Extensions/Reflection/ExpressionExtensions.cs b/src/DNX.Extensions/Reflection/ExpressionExtensions.cs
new file mode 100644
index 0000000..88281c6
--- /dev/null
+++ b/src/DNX.Extensions/Reflection/ExpressionExtensions.cs
@@ -0,0 +1,148 @@
+using System;
+using System.Linq.Expressions;
+
+namespace DNX.Extensions.Reflection
+{
+    /// <summary>
+    /// Class ExpressionExtensions.
+    /// </summary>
+    public static class ExpressionExtensions
+    {
+        /// <summary>
+        /// Determines whether the func is a member expression
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        /// <param name="func">The func.</param>
+        /// <returns></returns>
+        public static bool IsMemberExpression<T>(this Expression<Func<T>> func)
+        {
+            return func.Body is MemberExpression;
+        }
+
+        /// <summary>
+        /// Determines whether the action is a member expression
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        /// <param name="action">The action.</param>
+        /// <returns></returns>
+        public static bool IsMemberExpression<T>(this Expression<Action> action)
+        {
+            return action.Body is MemberExpression;
+        }
+
+        /// <summary>
+        /// Determines whether the func is a lambda expression
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        /// <param name="func">The func.</param>
+        /// <returns></returns>
+        public static bool IsLambdaExpression<T>(Expression<Func<T>> func)
+        {
+            return func.Body is LambdaExpression;
+        }
+
+        /// <summary>
+        /// Determines whether the action is a lambda expression
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        /// <param name="action">The action.</param>
+        /// <returns></returns>
+        public static bool IsLambdaExpression<T>(Expression<Action<T>> action)
+        {
+            return action.Body is LambdaExpression;
+        }
+
+        /// <summary>
+        /// Determines whether the func is a unary expression
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        /// <param name="func">The func.</param>
+        /// <returns></returns>
+        public static bool IsUnaryExpression<T>(Expression<Func<T>> func)
+        {
+            var unaryExpression = func.Body as UnaryExpression;
+
+            return unaryExpression != null;
+        }
+
+        /// <summary>
+        /// Determines whether the action is a unary expression
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        /// <param name="action">The action.</param>
+        /// <returns></returns>
+        public static bool IsUnaryExpression<T>(Expression<Action<T>> action)
+        {
+            var unaryExpression = action.Body as UnaryExpression;
+
+            return unaryExpression != null;
+        }
+
+        /// <summary>
+        /// Gets the name of the member expression.
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        /// <param name="func">The func.</param>
+        /// <returns></returns>
+        public static string GetMemberName<T>(Expression<Func<T>> func)
+        {
+            var memberExpression = func.Body as MemberExpression;
+
+            return memberExpression?.Member.Name;
+        }
+
+        /// <summary>
+        /// Gets the name of the lambda expression.
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        /// <param name="exp">The exp.</param>
+        /// <returns></returns>
+        public static string GetLambdaName<T>(Expression<Func<T>> exp)
+        {
+            var lambdaExpression = exp.Body as LambdaExpression;
+
+            return lambdaExpression?.Name;
+        }
+
+        /// <summary>
+        /// Gets the name of the unary expression.
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        /// <param name="exp">The exp.</param>
+        /// <returns></returns>
+        public static string GetUnaryName<T>(Expression<Func<T>> exp)
+        {
+            var unaryExpression = exp.Body as UnaryExpression; //((UnaryExpression)exp.Body).Operand;
+
+            var operand = unaryExpression?.Operand as MemberExpression;
+
+            return operand?.Member.Name;
+        }
+
+        /// <summary>
+        /// Gets the name of the expression.
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        /// <param name="exp">The exp.</param>
+        /// <returns></returns>
+        public static string GetExpressionName<T>(Expression<Func<T>> exp)
+        {
+            if (IsMemberExpression(exp))
+            {
+                return GetMemberName(exp);
+            }
+
+            if (IsLambdaExpression(exp))
+            {
+                return GetLambdaName(exp);
+            }
+
+            if (IsUnaryExpression(exp))
+            {
+                return GetUnaryName(exp);
+            }
+
+            return null;
+        }
+    }
+}
diff --git a/tests/DNX.Extensions.Tests/Reflection/ExpressionExtensionsTests.cs b/tests/DNX.Extensions.Tests/Reflection/ExpressionExtensionsTests.cs
new file mode 100644
index 0000000..3279413
--- /dev/null
+++ b/tests/DNX.Extensions.Tests/Reflection/ExpressionExtensionsTests.cs
@@ -0,0 +1,59 @@
+using DNX.Extensions.Reflection;
+using FluentAssertions;
+using Xunit;
+
+#pragma warning disable xUnit1044   // TestData not serializable
+
+namespace DNX.Extensions.Tests.Reflection;
+
+public class ExpressionExtensionsTests
+{
+    // TODO: Not sure how to test these
+
+
+
+
+    [Fact]
+    public void IsMemberExpression_func_Tests()
+    {
+        ExpressionExtensions.IsMemberExpression(() => BooleanFunc()).Should().BeFalse();
+        ExpressionExtensions.IsMemberExpression(() => StringFunc()).Should().BeFalse();
+        ExpressionExtensions.IsMemberExpression(() => Int32Func()).Should().BeFalse();
+        ExpressionExtensions.IsMemberExpression(() => DoubleFunc()).Should().BeFalse();
+    }
+
+    [Fact]
+    public void IsMemberExpression_action_Tests()
+    {
+        // TODO: This looks wrong
+        ExpressionExtensions.IsMemberExpression<object>(() => Action1()).Should().BeFalse();
+    }
+
+    [Fact]
+    public void IsLambdaExpression_func_Tests()
+    {
+        ExpressionExtensions.IsLambdaExpression(() => BooleanFunc()).Should().BeFalse();
+        ExpressionExtensions.IsLambdaExpression(() => StringFunc()).Should().BeFalse();
+        ExpressionExtensions.IsLambdaExpression(() => Int32Func()).Should().BeFalse();
+        ExpressionExtensions.IsLambdaExpression(() => DoubleFunc()).Should().BeFalse();
+    }
+
+    [Fact]
+    public void IsUnaryExpression_func_Tests()
+    {
+        ExpressionExtensions.IsUnaryExpression(() => BooleanFunc()).Should().BeFalse();
+        ExpressionExtensions.IsUnaryExpression(() => StringFunc()).Should().BeFalse();
+        ExpressionExtensions.IsUnaryExpression(() => Int32Func()).Should().BeFalse();
+        ExpressionExtensions.IsUnaryExpression(() => DoubleFunc()).Should().BeFalse();
+    }
+
+
+
+
+    private static bool BooleanFunc() => DateTime.UtcNow.Millisecond % 2 == 0;
+    private static string StringFunc() => Environment.MachineName;
+    private static int Int32Func() => DateTime.UtcNow.Second;
+    private static double DoubleFunc() => DateTime.UtcNow.Millisecond;
+
+    private static void Action1() { }
+}