fix(core): give empty Standard Schema issues a non-empty error

Author: MindOfqc

packages/core-internal/src/util/standardSchema.ts

@@ -285,7 +285,10 @@ export async function validateStandardSchema<T extends StandardSchemaV1>(
 ): Promise<StandardSchemaValidationResult<StandardSchemaV1.InferOutput<T>>> {
     const result = await schema['~standard'].validate(data);
     if (result.issues) {
-        return { success: false, error: result.issues.map(i => formatIssue(i)).join(', ') };
+        // A present but empty `issues` array is still a failure, so fall back to a
+        // non-empty message: callers that surface `error` must not report it as success.
+        const message = result.issues.map(i => formatIssue(i)).join(', ');
+        return { success: false, error: message || 'validation failed' };
     }
     return { success: true, data: (result as StandardSchemaV1.SuccessResult<unknown>).value as StandardSchemaV1.InferOutput<T> };
 }

packages/core-internal/test/util/standardSchema.test.ts

@@ -12,7 +12,10 @@ describe('validateStandardSchema', () => {
             }
         };
 
-        await expect(validateStandardSchema(schema, { name: 'example' })).resolves.toEqual({ success: false, error: '' });
+        await expect(validateStandardSchema(schema, { name: 'example' })).resolves.toEqual({
+            success: false,
+            error: 'validation failed'
+        });
     });
 
     test('preserves transformed values when validation succeeds', async () => {