fixes

Author: nolannbiron

packages/react-openapi/src/OpenAPISchema.tsx

@@ -550,7 +550,7 @@ export function getSchemaAlternatives(
                 type,
                 flattenAlternatives(type, schemas, new Set(ancestors).add(schema))
             ) ?? [],
-        ...(discriminator ? { discriminator } : {}),
+        discriminator,
     };
 }
 
@@ -653,9 +653,7 @@ function mergeAlternatives(
                                     : []),
                             ])
                         );
-                        if (latest.nullable || schemaOrRef.nullable) {
-                            latest.nullable = latest.nullable || schemaOrRef.nullable;
-                        }
+                        latest.nullable = latest.nullable || schemaOrRef.nullable;
 
                         // Preserve safe extensions and vendor extensions
                         // Always overwrite (last schema has priority)
@@ -688,6 +686,7 @@ function flattenAlternatives(
     schemasOrRefs: (OpenAPIV3.SchemaObject | OpenAPIV3.ReferenceObject)[],
     ancestors: Set<OpenAPIV3.SchemaObject>
 ): OpenAPIV3.SchemaObject[] {
+    // Get the parent schema's required fields from the most recent ancestor
     const latestAncestor = Array.from(ancestors).pop();
     const result: OpenAPIV3.SchemaObject[] = [];
 
@@ -706,6 +705,9 @@ function flattenAlternatives(
     return result;
 }
 
+/**
+ * Flatten a schema that is an alternative of another schema.
+ */
 function flattenSchema(
     schema: OpenAPIV3.SchemaObject,
     alternativeType: AlternativeType,

packages/react-openapi/src/contentTypeChecks.ts

@@ -34,6 +34,6 @@ export function isFormData(contentType?: string): boolean {
     return !!contentType && contentType.toLowerCase().includes('multipart/form-data');
 }
 
-export function isPlainObject(value: unknown): boolean {
+export function isPlainObject(value: unknown): value is Record<string, unknown> {
     return typeof value === 'object' && value !== null && !Array.isArray(value);
 }

packages/react-openapi/src/generateSchemaExample.test.ts

@@ -1038,36 +1038,6 @@ describe('generateSchemaExample', () => {
         ).toBeUndefined();
     });
 
-    it('handles oneOf -> allOf returning a string without spreading characters', () => {
-        // Create a circular reference that will return "[Circular Reference]" string
-        const circularSchema = {
-            type: 'object',
-            properties: {
-                nested: {},
-            },
-        } satisfies OpenAPIV3.SchemaObject;
-        circularSchema.properties.nested = circularSchema;
-
-        const schema = {
-            type: 'object',
-            properties: {
-                foo: {
-                    type: 'string',
-                },
-            },
-            oneOf: [
-                {
-                    allOf: [circularSchema],
-                },
-            ],
-        } satisfies OpenAPIV3.SchemaObject;
-
-        const result = generateSchemaExample(schema);
-
-        expect(result).toBeDefined();
-        expect(result).toHaveProperty('foo');
-    });
-
     it('merges object properties from oneOf -> allOf', () => {
         const schema = {
             type: 'object',

packages/react-openapi/src/generateSchemaExample.ts

@@ -1,4 +1,5 @@
 import type { OpenAPIV3 } from '@gitbook/openapi-parser';
+import { isPlainObject } from './contentTypeChecks';
 import { checkIsReference } from './utils';
 
 type JSONValue = string | number | boolean | null | JSONValue[] | { [key: string]: JSONValue };
@@ -99,13 +100,6 @@ function guessFromFormat(schema: Record<string, any>, fallback = '') {
     return genericExampleValues[schema.format] ?? fallback;
 }
 
-/**
- * Check if a value is a plain object (not null, not array)
- */
-function isPlainObject(value: unknown): value is Record<string, unknown> {
-    return typeof value === 'object' && value !== null && !Array.isArray(value);
-}
-
 /**
  * This function takes an OpenAPI schema and generates an example from it
  * Forked from : https://github.com/scalar/scalar/blob/main/packages/oas-utils/src/spec-getters/getExampleFromSchema.ts