Add a DefaultContentType setting to OpenApiReaderSettings

Author: MaggieKimani1

src/Microsoft.OpenApi.Readers/OpenApiReaderSettings.cs

@@ -62,6 +62,11 @@ public class OpenApiReaderSettings
         /// </summary>
         public Uri BaseUrl { get; set; }
 
+        /// <summary>
+        /// Allows clients to define a custom DefaultContentType if produces array is empty
+        /// </summary>
+        public List<string> DefaultContentType { get; set; }
+
         /// <summary>
         /// Function used to provide an alternative loader for accessing external references.
         /// </summary>

src/Microsoft.OpenApi.Readers/OpenApiYamlDocumentReader.cs

@@ -47,7 +47,8 @@ public OpenApiDocument Read(YamlDocument input, out OpenApiDiagnostic diagnostic
             var context = new ParsingContext(diagnostic)
             {
                 ExtensionParsers = _settings.ExtensionParsers,
-                BaseUrl = _settings.BaseUrl
+                BaseUrl = _settings.BaseUrl,
+                DefaultContentType = _settings.DefaultContentType
             };
 
             OpenApiDocument document = null;

src/Microsoft.OpenApi.Readers/ParsingContext.cs

@@ -29,6 +29,7 @@ public class ParsingContext
         internal RootNode RootNode { get; set; }
         internal List<OpenApiTag> Tags { get; private set; } = new List<OpenApiTag>();
         internal Uri BaseUrl { get; set; }
+        internal List<string> DefaultContentType { get; set; }
 
         /// <summary>
         /// Diagnostic object that returns metadata about the parsing process.