test(graph_engine): block response nodes during streaming (#26377)

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

api/tests/unit_tests/core/workflow/graph_engine/test_answer_order_workflow.py

@@ -0,0 +1,28 @@
+from .test_mock_config import MockConfigBuilder
+from .test_table_runner import TableTestRunner, WorkflowTestCase
+
+LLM_NODE_ID = "1759052580454"
+
+
+def test_answer_nodes_emit_in_order() -> None:
+    mock_config = (
+        MockConfigBuilder()
+        .with_llm_response("unused default")
+        .with_node_output(LLM_NODE_ID, {"text": "mocked llm text"})
+        .build()
+    )
+
+    expected_answer = "--- answer 1 ---\n\nfoo\n--- answer 2 ---\n\nmocked llm text\n"
+
+    case = WorkflowTestCase(
+        fixture_path="test-answer-order",
+        query="",
+        expected_outputs={"answer": expected_answer},
+        use_auto_mock=True,
+        mock_config=mock_config,
+    )
+
+    runner = TableTestRunner()
+    result = runner.run_test_case(case)
+
+    assert result.success, result.error