feat: Add writer settings to enable sorting collections using a comparer

Author: MaggieKimani1

src/Microsoft.OpenApi/Extensions/DictionaryExtensions.cs

@@ -0,0 +1,51 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace Microsoft.OpenApi.Extensions
+{
+    /// <summary>
+    /// Dictionary extension methods
+    /// </summary>
+    public static class DictionaryExtensions
+    {
+        /// <summary>
+        /// Returns a new dictionary with entries sorted by key using the default comparer.
+        /// </summary>
+        public static IDictionary<TKey, TValue> Sort<TKey, TValue>(
+            this IDictionary<TKey, TValue> source)
+            where TKey : notnull
+        {
+#if NET7_0_OR_GREATER
+            ArgumentNullException.ThrowIfNull(nameof(source));
+#else
+            if (source == null)
+                throw new ArgumentNullException(nameof(source));
+#endif
+
+            return source.OrderBy(kvp => kvp.Key)
+                               .ToDictionary(kvp => kvp.Key, kvp => kvp.Value);
+        }
+
+        /// <summary>
+        /// Returns a new dictionary with entries sorted by key using a custom comparer.
+        /// </summary>
+        public static IDictionary<TKey, TValue> Sort<TKey, TValue>(
+            this IDictionary<TKey, TValue> source,
+            IComparer<TKey> comparer)
+            where TKey : notnull
+        {
+#if NET7_0_OR_GREATER
+            ArgumentNullException.ThrowIfNull(nameof(source));
+            ArgumentNullException.ThrowIfNull(nameof(comparer));
+#else
+            if (source == null)
+                throw new ArgumentNullException(nameof(source));
+            if (comparer == null)
+                throw new ArgumentNullException(nameof(comparer));
+#endif
+            return source.OrderBy(kvp => kvp.Key, comparer)
+                               .ToDictionary(kvp => kvp.Key, kvp => kvp.Value);
+        }
+    }
+}

src/Microsoft.OpenApi/Writers/OpenApiWriterExtensions.cs

@@ -6,6 +6,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Text.Json.Nodes;
+using Microsoft.OpenApi.Extensions;
 using Microsoft.OpenApi.Interfaces;
 
 namespace Microsoft.OpenApi.Writers
@@ -458,6 +459,17 @@ private static void WriteMapInternal<T>(
 
             if (elements != null)
             {
+                var settings = writer.GetSettings();
+
+                if (settings?.EnableSorting == true)
+                {
+                    elements = elements.Sort(); // sort with default comparer
+                }
+                else if (settings?.KeyComparer != null)
+                {
+                    elements = elements.Sort(settings.KeyComparer); // sort using custom comparer
+                }
+
                 foreach (var item in elements)
                 {
                     writer.WritePropertyName(item.Key);

src/Microsoft.OpenApi/Writers/OpenApiWriterSettings.cs

@@ -1,3 +1,4 @@
+using System.Collections.Generic;
 using Microsoft.OpenApi.Models;
 using Microsoft.OpenApi.Services;
 
@@ -24,5 +25,15 @@ internal bool ShouldInlineReference(OpenApiReference reference)
             return (reference.IsLocal && InlineLocalReferences)
                              || (reference.IsExternal && InlineExternalReferences);
         }
+
+        /// <summary>  
+        /// Enables sorting of collections using the default comparer  
+        /// </summary>  
+        public bool EnableSorting { get; set; }
+
+        /// <summary>  
+        /// Custom comparer for sorting collections.  
+        /// </summary>  
+        public IComparer<string>? KeyComparer { get; set; }
     }
 }