fix(groq): handle empty object schemas for Groq structured output

Ensure object schemas always have a properties field and remove required
when there are no properties, as Groq rejects empty required arrays

Author: Dhamivibez

packages/typescript/ai-groq/src/tools/function-tool.ts

@@ -20,6 +20,11 @@ export function convertFunctionToolToAdapterFormat(tool: Tool): FunctionTool {
     required: [],
   }) as JSONSchema
 
+  // Ensure object schemas always have properties (e.g. z.object({}) may produce { type: 'object' } without properties)
+  if (inputSchema.type === 'object' && !inputSchema.properties) {
+    inputSchema.properties = {}
+  }
+
   const jsonSchema = makeGroqStructuredOutputCompatible(
     inputSchema,
     inputSchema.required || [],

packages/typescript/ai-groq/src/utils/schema-converter.ts

@@ -87,6 +87,12 @@ export function makeGroqStructuredOutputCompatible(
     }
 
     result.properties = properties
+    // Groq rejects `required` when there are no properties, even if it's an empty array
+    if (allPropertyNames.length > 0) {
+      result.required = allPropertyNames
+    } else {
+      delete result.required
+    }
     result.required = allPropertyNames
     result.additionalProperties = false
   }