From a373176e275512db85b63f0ee9a5b4126a6c1010 Mon Sep 17 00:00:00 2001
From: Nikolay Pozdnichenko <nick680@gmail.com>
Date: Mon, 18 Mar 2024 13:50:09 +0600
Subject: [PATCH] Some small refactorings

---
 Libiada.Core/Core/IBaseObject.cs                  | 8 +++++++-
 Libiada.Core/DataTransformers/HighOrderFactory.cs | 3 ++-
 Libiada.Core/Extensions/EnumExtensions.cs         | 6 +++---
 3 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/Libiada.Core/Core/IBaseObject.cs b/Libiada.Core/Core/IBaseObject.cs
index e831abaf..24686e21 100644
--- a/Libiada.Core/Core/IBaseObject.cs
+++ b/Libiada.Core/Core/IBaseObject.cs
@@ -21,7 +21,7 @@ public interface IBaseObject
     /// Object to compare to.
     /// </param>
     /// <returns>
-    /// true of objects are equal and false otherwise.
+    /// True if objects are equal and false otherwise.
     /// </returns>
     bool Equals(object other);
 
@@ -33,4 +33,10 @@ public interface IBaseObject
     /// The <see cref="int"/>.
     /// </returns>
     int GetHashCode();
+
+    /// <summary>
+    /// Converts <see cref="IBaseObject"/> to <see cref="string"/>
+    /// </summary>
+    /// <returns></returns>
+    string ToString();
 }
diff --git a/Libiada.Core/DataTransformers/HighOrderFactory.cs b/Libiada.Core/DataTransformers/HighOrderFactory.cs
index 80da1356..ee93a8b4 100644
--- a/Libiada.Core/DataTransformers/HighOrderFactory.cs
+++ b/Libiada.Core/DataTransformers/HighOrderFactory.cs
@@ -26,7 +26,8 @@ public static class HighOrderFactory
     /// </exception>
     public static Chain Create(Chain source, Link link)
     {
-        if (link != Link.Start && link != Link.End && link != Link.CycleEnd && link != Link.CycleStart)
+        Link[] applicableLinks = [Link.Start, Link.End, Link.CycleEnd, Link.CycleStart];
+        if (!applicableLinks.Contains(link))
         {
             throw new ArgumentException("Unknown or inapplicable link", nameof(link));
         }
diff --git a/Libiada.Core/Extensions/EnumExtensions.cs b/Libiada.Core/Extensions/EnumExtensions.cs
index 37d3a7c7..6f676d30 100644
--- a/Libiada.Core/Extensions/EnumExtensions.cs
+++ b/Libiada.Core/Extensions/EnumExtensions.cs
@@ -37,7 +37,7 @@ public static string GetDisplayValue<T>(this T value) where T : struct, ICompara
 
         var fieldInfo = type.GetField(value.ToString(CultureInfo.InvariantCulture));
 
-        var descriptionAttributes = fieldInfo.GetCustomAttributes(typeof(DisplayAttribute), false) as DisplayAttribute[];
+        var descriptionAttributes = fieldInfo?.GetCustomAttributes(typeof(DisplayAttribute), false) as DisplayAttribute[];
 
         if (descriptionAttributes == null)
         {
@@ -57,12 +57,12 @@ public static string GetDisplayValue<T>(this T value) where T : struct, ICompara
     /// Enum type.
     /// </typeparam>
     /// <returns>
-    /// The <see cref="string"/>.
+    /// The <see cref="string"/> or <see langword="null"/> if value is not found.
     /// </returns>
     /// <exception cref="TypeArgumentException">
     /// Thrown if type argument is not enum.
     /// </exception>
-    public static string GetName<T>(this T value) where T : struct, IComparable, IFormattable, IConvertible
+    public static string? GetName<T>(this T value) where T : struct, IComparable, IFormattable, IConvertible
     {
         Type type = typeof(T);