clean up and dispose stream if specified in the settings

Author: MaggieKimani1

src/Microsoft.OpenApi/Reader/OpenApiJsonReader.cs

@@ -11,11 +11,7 @@
 using Microsoft.OpenApi.Extensions;
 using Microsoft.OpenApi.Validations;
 using System.Linq;
-using Microsoft.OpenApi.Services;
 using Microsoft.OpenApi.Interfaces;
-using Microsoft.OpenApi.Reader.Services;
-using System.Collections.Generic;
-using System;
 
 namespace Microsoft.OpenApi.Reader
 {

src/Microsoft.OpenApi/Reader/OpenApiModelFactory.cs

@@ -118,7 +118,7 @@ public static async Task<ReadResult> LoadAsync(string url, OpenApiReaderSettings
         public static async Task<T> LoadAsync<T>(string url, OpenApiSpecVersion version, OpenApiReaderSettings settings = null) where T : IOpenApiElement
         {
             var result = await RetrieveStreamAndFormatAsync(url);
-            return Load<T>(result.Item1 as MemoryStream, version, result.Item2, out var diagnostic, settings);
+            return Load<T>(result.Item1, version, result.Item2, out var diagnostic, settings);
         }
 
         /// <summary>
@@ -149,8 +149,18 @@ public static async Task<ReadResult> LoadAsync(Stream input, string format = nul
                 preparedStream.Position = 0;
             }
 
-            // Use StreamReader to process the prepared stream (buffered for YAML, direct for JSON)
-            return await InternalLoadAsync(preparedStream, format, settings, cancellationToken);
+            try
+            {
+                // Use StreamReader to process the prepared stream (buffered for YAML, direct for JSON)
+                return await InternalLoadAsync(preparedStream, format, settings, cancellationToken);
+            }
+            finally
+            {
+                if (!settings.LeaveStreamOpen)
+                {
+                    input.Dispose();
+                }
+            }
         }
 
         /// <summary>

test/Microsoft.OpenApi.Readers.Tests/V3Tests/OpenApiDiscriminatorTests.cs

@@ -28,6 +28,7 @@ public async Task ParseBasicDiscriminatorShouldSucceed()
             // Copy stream to MemoryStream
             using var memoryStream = new MemoryStream();
             await stream.CopyToAsync(memoryStream);
+            memoryStream.Position = 0;
 
             // Act
             var discriminator = OpenApiModelFactory.Load<OpenApiDiscriminator>(memoryStream, OpenApiSpecVersion.OpenApi3_0, OpenApiConstants.Yaml, out var diagnostic);