Cleanup

Author: Youssef1313

src/Microsoft.OpenApi/Models/OpenApiSchema.cs

@@ -114,12 +114,6 @@ public string? ExclusiveMinimum
         private bool HasNullType
             => Type.HasValue && Type.Value.HasFlag(JsonSchemaType.Null);
 
-        private bool HasTrueNullableExtension
-            => Extensions is not null &&
-                Extensions.TryGetValue(OpenApiConstants.NullableExtension, out var nullExtRawValue) &&
-                nullExtRawValue is JsonNodeExtension { Node: JsonNode jsonNode } &&
-                jsonNode.GetValueKind() is JsonValueKind.True;
-
         /// <inheritdoc />
         public string? Const { get; set; }
 
@@ -790,18 +784,6 @@ internal void WriteAsItemsProperties(IOpenApiWriter writer)
             writer.WriteExtensions(Extensions, OpenApiSpecVersion.OpenApi2_0);
         }
 
-        internal void FinalizeDeserialization(OpenApiSpecVersion version)
-        {
-            if (version is OpenApiSpecVersion.OpenApi2_0 or OpenApiSpecVersion.OpenApi3_0 && HasTrueNullableExtension)
-            {
-                Extensions!.Remove(OpenApiConstants.NullableExtension);
-                if (Type is not null && Type != 0)
-                {
-                    Type |= JsonSchemaType.Null;
-                }
-            }
-        }
-
         private void WriteFormatProperty(IOpenApiWriter writer)
         {
             var formatToWrite = Format;

src/Microsoft.OpenApi/Reader/V2/OpenApiSchemaDeserializer.cs

@@ -268,7 +268,16 @@ public static IOpenApiSchema LoadSchema(JsonNode node, OpenApiDocument hostDocum
 
             ParseMap(jsonObject, schema, _openApiSchemaFixedFields, _openApiSchemaPatternFields, hostDocument, context);
 
-            schema.FinalizeDeserialization(OpenApiSpecVersion.OpenApi2_0);
+            var extensions = schema.Extensions;
+            if (extensions?.TryGetValue(OpenApiConstants.NullableExtension, out var nullExtRawValue) == true &&
+                nullExtRawValue is JsonNodeExtension { Node: JsonNode jsonNode })
+            {
+                extensions.Remove(OpenApiConstants.NullableExtension);
+                if (schema.Type is not null && schema.Type != 0 && jsonNode.GetValueKind() is JsonValueKind.True)
+                {
+                    schema.Type |= JsonSchemaType.Null;
+                }
+            }
 
             return schema;
         }

src/Microsoft.OpenApi/Reader/V3/OpenApiSchemaDeserializer.cs

@@ -233,8 +233,8 @@ internal static partial class OpenApiV3Deserializer
                         {
                             // While we are dealing with v3 document, we are still using x-nullable extension here.
                             // This is used only as a marker during deserialization to indicate that the schema is nullable.
-                            // When we do FinalizeDeserialization, we will modify the OpenApiSchema.Type to
-                            // include JsonSchemaType.Null (only if needed), and always remove the extension.
+                            // When we complete the deserialization, we will modify the OpenApiSchema.Type to
+                            // include JsonSchemaType.Null (**only if** needed), and always remove the extension.
                             // The reason is that "nullable" property should only take effect if "Type" is set.
                             // If we knew Type is set, we add "Null" to it.
                             // Otherwise, it might be that it will be set later.
@@ -400,7 +400,19 @@ public static IOpenApiSchema LoadSchema(JsonNode node, OpenApiDocument hostDocum
 
             ParseMap(jsonObject, schema, _openApiSchemaFixedFields, _openApiSchemaPatternFields, hostDocument, context);
 
-            schema.FinalizeDeserialization(OpenApiSpecVersion.OpenApi3_0);
+            if (schema.Extensions?.TryGetValue(OpenApiConstants.NullableExtension, out var value) == true &&
+                value == _nullableTrueExtension)
+            {
+                // If this is "our own" internal _nullableTrueExtension instance, then we know we encountered "nullable": true in the schema
+                // at a point where Type wasn't set yet.
+                // We check now if schema.Type is set.
+                // If it is, we add JsonSchemaType.Null to it.
+                schema.Extensions.Remove(OpenApiConstants.NullableExtension);
+                if (schema.Type is not null && schema.Type != 0)
+                {
+                    schema.Type |= JsonSchemaType.Null;
+                }
+            }
 
             return schema;
         }

src/Microsoft.OpenApi/Reader/V31/OpenApiSchemaDeserializer.cs

@@ -459,8 +459,6 @@ public static IOpenApiSchema LoadSchema(JsonNode node, OpenApiDocument hostDocum
                 schema.UnrecognizedKeywords[name] = value;
             });
 
-        schema.FinalizeDeserialization(OpenApiSpecVersion.OpenApi3_1);
-
         if (!string.IsNullOrEmpty(identifier) && hostDocument.Workspace is not null)
         {
             // register the schema in our registry using the identifier's URL

src/Microsoft.OpenApi/Reader/V32/OpenApiSchemaDeserializer.cs

@@ -459,8 +459,6 @@ public static IOpenApiSchema LoadSchema(JsonNode node, OpenApiDocument hostDocum
                 schema.UnrecognizedKeywords[name] = value;
             });
 
-        schema.FinalizeDeserialization(OpenApiSpecVersion.OpenApi3_2);
-
         if (!string.IsNullOrEmpty(identifier) && hostDocument.Workspace is not null)
         {
             // register the schema in our registry using the identifier's URL