Handle nullable types in OpenAPI schemas and add corresponding unit t… #7170

gavinbarron · 2026-01-23T18:26:51Z

This need test coverage to ensure the deserialization code is generated correctly for the case of a union model with an integer enum.

I am not entirely sure what you mean by that, could you provide a sample json?
Also, where are those tests currently located at?

Thanks in advance

Here's where the tests for this method start:

kiota/tests/Kiota.Builder.Tests/Writers/CSharp/CodeMethodWriterTests.cs

Line 592 in 2848c0b

public void WritesModelFactoryBodyForUnionModels()

A union model with and integer enum might looks something like:

openapi: 3.0.3 info: title: Union with Integer Enum API version: 1.0.0 servers: - url: https://api.example.com/v1 paths: /status: get: summary: Get status that can be multiple types responses: '200': description: A union type containing an integer enum content: application/json: schema: $ref: '#/components/schemas/StatusUnion' components: schemas: # Integer-backed enum StatusEnum: type: integer enum: [0, 1, 2] x-ms-enum: name: StatusEnum modelAsString: false values: - name: Active value: 0 description: "The resource is active" - name: Inactive value: 1 description: "The resource is inactive" - name: Pending value: 2 description: "The resource is pending" # A complex object type DetailedStatus: type: object required: - message properties: message: type: string code: type: integer # Union model combining integer enum and object StatusUnion: oneOf: - $ref: '#/components/schemas/StatusEnum' - $ref: '#/components/schemas/DetailedStatus' discriminator: propertyName: '@odata.type' mapping: '#kiota.statusEnum': '#/components/schemas/StatusEnum' '#kiota.detailedStatus': '#/components/schemas/DetailedStatus'

gavinbarron · 2026-01-23T18:27:11Z

This need test coverage to ensure the deserialization code is generated correctly for the case of a intersection model with an integer enum.

I am not entirely sure what you mean by that, could you provide a sample json?
Also, where are those tests currently located at?

Thanks in advance

Intersection model tests start here:

kiota/tests/Kiota.Builder.Tests/Writers/CSharp/CodeMethodWriterTests.cs

Line 891 in 2848c0b

public void WritesModelFactoryBodyForIntersectionModels()

Example of an intersection model based on the previous union model example

StatusIntersection: allOf: - $ref: '#/components/schemas/StatusEnum' - $ref: '#/components/schemas/DetailedStatus'

gavinbarron · 2026-01-23T18:19:13Z

I'm not seeing any tests for serialization of union models that include Integer Enums, let's make sure test cases for this are added.

It feels a bit weird that the integer case is passing otherProp.WireName which is inconsistent with how the existing case works.

I am very aware of that, wanted to avoid cross-repository changes tho and have this easily integrateable on my end.

Could you hint me at where those tests are currently placed and how they look? Thanks in advance.

Here's where we have an existing test for the union model serialization

kiota/tests/Kiota.Builder.Tests/Writers/CSharp/CodeMethodWriterTests.cs

Line 1394 in 2848c0b

public void WritesUnionDeSerializerBody()

It focuses on the code that is generated, rather than the behavior of the serialization library that we have as a dependency.

gavinbarron · 2026-01-23T18:19:37Z

I'm not seeing any tests for serialization of intersection models that include Integer Enums, let's make sure test cases for this are added.

I am not entirely sure what you mean by that, could you provide a sample json?
Also, where are those tests currently located at?

Thanks in advance

Here's the existing test for generating the serialization method

kiota/tests/Kiota.Builder.Tests/Writers/CSharp/CodeMethodWriterTests.cs

Line 1419 in 2848c0b

public void WritesIntersectionDeSerializerBody()

I have supplied sample open api for these types of schema on the factory method/deserialization comments

-Original file line number
+Diff line change
@@ Expand Up / @@ -2,6 +2,7 @@ @@
     using System.Collections.Concurrent;
     using System.Collections.Generic;
     using System.Linq;
+    using Microsoft.OpenApi;
     namespace Kiota.Builder.CodeDOM;
     #pragma warning disable CA1711
@@ Expand Down Expand Up / @@ -42,4 +43,9 @@ public CodeConstant? CodeEnumObject @@
         {
             get; set;
         }
+        public JsonSchemaType? BackingType
+        {
+            get; set;
+        }
     }

-Original file line number
+Diff line change
@@ Expand Up @@
             return schema switch
             {
                 OpenApiSchemaReference reference => reference.Reference?.Id,
+                // Quickfix for https://github.com/microsoft/kiota/issues/6776 ToDo: Properly handle nullable types in accordance with OpenAPI 3.
+                OpenApiSchema {OneOf: [OpenApiSchema{Type: JsonSchemaType.Null}, OpenApiSchemaReference reference]} => reference.Reference?.Id,
                 OpenApiSchema s when s.GetMergedSchemaOriginalReferenceId() is string originalReferenceId => originalReferenceId,
                 _ => null,
             };
@@ Expand All @@
             return schema switch
             {
                 OpenApiSchemaReference => true,
+                // Quickfix for https://github.com/microsoft/kiota/issues/6776 ToDo: Properly handle nullable types in accordance with OpenAPI 3.
+                OpenApiSchema {OneOf: [OpenApiSchema{Type: JsonSchemaType.Null}, OpenApiSchemaReference reference]} => true,
                 _ => false,
             };
         }
@@ Expand Down Expand Up @@
             return schema.HasAnyProperty() ||
                     (!ignoreEnums && schema.Enum is { Count: > 0 }) ||
                     (!ignoreArrays && schema.Items != null) ||
-                    (!ignoreType && schema.Type is not null &&
+                    (!ignoreType && schema.Type is not null and not JsonSchemaType.Null &&
                         ((ignoreNullableObjects && !schema.IsObjectType()) ||
                         !ignoreNullableObjects)) ||
                     !string.IsNullOrEmpty(schema.Format) ||
@@ Expand Down @@

-Original file line number
+Diff line change
@@ Expand Up @@
                                             currentNode.GetPathItemDescription(Constants.DefaultOpenApiLabel),
                     },
                     Deprecation = schema.GetDeprecationInformation(),
+                    BackingType = schema.Type,
                 };
                 SetEnumOptions(schema, newEnum);
                 return currentNamespace.AddEnum(newEnum).First();
@@ Expand Down @@

-Original file line number
+Diff line change
@@ -1,4 +1,5 @@
     using System.Collections.Generic;
+    using System.Linq;
     using Kiota.Builder.Extensions;
     using Microsoft.OpenApi;
     using Xunit;
@@ Expand Down Expand Up / @@ -80,6 +81,18 @@ public void ExternalReferencesAreSupported() @@
             Assert.True(mockSchema.IsReferencedSchema());
         }
         [Fact]
+        public void ExternalNullableReferencesAreSupported()
+        {
+            var mockSchema = new OpenApiSchema
+            {
+                OneOf = [
+                    new OpenApiSchema{Type = JsonSchemaType.Null},
+                    new OpenApiSchemaReference("example.json#/path/to/component", null, "http://example.com/example.json")
+                ]
+            };
+            Assert.True(mockSchema.IsReferencedSchema());
+        }
+        [Fact]
         public void SchemasAreNotConsideredReferences()
         {
             var mockSchema = new OpenApiSchema();
@@ Expand Down Expand Up / @@ -356,6 +369,20 @@ public void GetReferenceIdsOneOf() @@
             Assert.Contains("microsoft.graph.user", names);
         }
         [Fact]
+        public void GetReferenceIdsOneOfNullable()
+        {
+            var schema = new OpenApiSchema
+            {
+                OneOf = [
+                    new OpenApiSchema{Type = JsonSchemaType.Null},
+                    new OpenApiSchemaReference("microsoft.graph.user")
+                ]
+            };
+            var names = schema.GetSchemaReferenceIds();
+            var name = Assert.Single(names);
+            Assert.Contains("microsoft.graph.user", name);
+        }
+        [Fact]
         public void GetReferenceIdsItems()
         {
             var schema = new OpenApiSchema
@@ Expand Down @@

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Handle nullable types in OpenAPI schemas and add corresponding unit t… #7170

Diff view

Diff view

There are no files selected for viewing

Uh oh!

gavinbarron Jan 23, 2026

Uh oh!

X39 Jan 27, 2026

Uh oh!

gavinbarron Jan 28, 2026

Uh oh!

gavinbarron Jan 23, 2026

Uh oh!

X39 Jan 27, 2026

Uh oh!

gavinbarron Jan 28, 2026

Uh oh!

gavinbarron Jan 23, 2026

Uh oh!

X39 Jan 27, 2026

Uh oh!

gavinbarron Jan 28, 2026

Uh oh!

gavinbarron Jan 23, 2026

Uh oh!

X39 Jan 27, 2026

Uh oh!

gavinbarron Jan 28, 2026

Uh oh!

Uh oh!

Handle nullable types in OpenAPI schemas and add corresponding unit t… #7170

Are you sure you want to change the base?

Handle nullable types in OpenAPI schemas and add corresponding unit t… #7170

Uh oh!

Uh oh!

Diff view

Diff view

There are no files selected for viewing

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!