fix (provider/google): support conversion of string enums to openapi spec (#4373)

Author: lgrammel

.changeset/breezy-peas-reply.md

@@ -0,0 +1,5 @@
+---
+'@ai-sdk/google': patch
+---
+
+fix (provider/google): support conversion of string enums to openapi spec

examples/ai-core/src/generate-object/google-complex-2.ts

@@ -0,0 +1,23 @@
+import { google } from '@ai-sdk/google';
+import { generateObject } from 'ai';
+import 'dotenv/config';
+import { z } from 'zod';
+
+async function main() {
+  // enum support:
+  const result = await generateObject({
+    model: google('gemini-exp-1206'),
+    schema: z.object({
+      title: z.string(),
+      kind: z.enum(['text', 'code', 'image']),
+    }),
+    prompt: 'Generate a software artifact.',
+  });
+
+  console.log(JSON.stringify(result.object, null, 2));
+  console.log();
+  console.log('Token usage:', result.usage);
+  console.log('Finish reason:', result.finishReason);
+}
+
+main().catch(console.error);

packages/google/src/convert-json-schema-to-openapi-schema.test.ts

@@ -479,12 +479,12 @@ it('should return undefined for empty object schemas', () => {
 });
 
 it('should handle non-empty object schemas', () => {
-  const nonEmptySchema = {
+  const nonEmptySchema: JSONSchema7 = {
     type: 'object',
     properties: {
       name: { type: 'string' },
     },
-  } as const;
+  };
 
   expect(convertJSONSchemaToOpenAPISchema(nonEmptySchema)).toEqual({
     type: 'object',
@@ -493,3 +493,29 @@ it('should handle non-empty object schemas', () => {
     },
   });
 });
+
+it('should convert string enum properties', () => {
+  const schemaWithEnumProperty: JSONSchema7 = {
+    type: 'object',
+    properties: {
+      kind: {
+        type: 'string',
+        enum: ['text', 'code', 'image'],
+      },
+    },
+    required: ['kind'],
+    additionalProperties: false,
+    $schema: 'https://json-schema.org/draft/2019-09/schema#',
+  };
+
+  expect(convertJSONSchemaToOpenAPISchema(schemaWithEnumProperty)).toEqual({
+    type: 'object',
+    properties: {
+      kind: {
+        type: 'string',
+        enum: ['text', 'code', 'image'],
+      },
+    },
+    required: ['kind'],
+  });
+});

packages/google/src/convert-json-schema-to-openapi-schema.ts

@@ -27,6 +27,7 @@ export function convertJSONSchemaToOpenAPISchema(
     format,
     const: constValue,
     minLength,
+    enum: enumValues,
   } = jsonSchema;
 
   const result: Record<string, unknown> = {};
@@ -55,6 +56,11 @@ export function convertJSONSchemaToOpenAPISchema(
     }
   }
 
+  // Handle enum
+  if (enumValues !== undefined) {
+    result.enum = enumValues;
+  }
+
   if (properties != null) {
     result.properties = Object.entries(properties).reduce(
       (acc, [key, value]) => {
@@ -81,7 +87,9 @@ export function convertJSONSchemaToOpenAPISchema(
     result.oneOf = oneOf.map(convertJSONSchemaToOpenAPISchema);
   }
 
-  if (minLength !== undefined) result.minLength = minLength;
+  if (minLength !== undefined) {
+    result.minLength = minLength;
+  }
 
   return result;
 }