feat: hold monitor when serve app fail to start

src/promptflow-devkit/promptflow/_sdk/_utilities/chat_utils.py

@@ -141,4 +141,8 @@ def start_chat_ui_service_monitor(
     try:
         monitor.start_monitor()
     except KeyboardInterrupt:
-        print("Stopping monitor...")
+        print("Stopping monitor and attached serve app...")
+        serve_app_helper = monitor.last_callback_result
+        if serve_app_helper is not None:
+            serve_app_helper.terminate()
+        print("Stopped monitor and attached serve app.")

src/promptflow-devkit/promptflow/_sdk/_utilities/general_utils.py

@@ -1139,7 +1139,8 @@ def resolve_flow_language(
     if flow_path is not None and yaml_dict is not None:
         raise UserErrorException("Only one of flow_path and yaml_dict should be provided.")
     if flow_path is not None:
-        flow_path, flow_file = resolve_flow_path(flow_path, base_path=working_dir)
+        # flow path must exist
+        flow_path, flow_file = resolve_flow_path(flow_path, base_path=working_dir, check_flow_exist=True)
         file_path = flow_path / flow_file
         if file_path.is_file() and file_path.suffix.lower() in (".yaml", ".yml"):
             yaml_dict = load_yaml(file_path)

src/promptflow-devkit/promptflow/_sdk/_utilities/monitor_utils.py

@@ -165,6 +165,10 @@ def __init__(
         self._last_callback_result = None
         self._inject_last_callback_result = inject_last_callback_result
 
+    @property
+    def last_callback_result(self):
+        return self._last_callback_result
+
     def start_monitor(self, interval=0.1):
         """Start monitoring the targets.
 

src/promptflow-devkit/tests/sdk_cli_test/unittests/test_monitor_utils.py

@@ -32,6 +32,11 @@ def _update_stat(self, key: str, cache: dict) -> bool:
         return True
 
 
+def write_json(file_path, data):
+    with open(file_path, "w", encoding="utf-8") as f:
+        json.dump(data, f)
+
+
 @pytest.mark.unittest
 class TestMonitorUtils:
     def test_directory_modification_monitor_target(self):
@@ -48,7 +53,7 @@ def test_directory_modification_monitor_target(self):
             (temp_dir / "test.txt").touch()
             assert monitor_target.update_cache(cache) is True, "file added"
             assert monitor_target.update_cache(cache) is False, "same content"
-            (temp_dir / "test.txt").write_text("test")
+            write_json(temp_dir / "test.txt", "test")
             assert monitor_target.update_cache(cache) is True, "content changed"
             assert monitor_target.update_cache(cache) is False, "same content"
 
@@ -83,8 +88,8 @@ def test_content_modification_monitor_target(self):
         cache = {}
 
         with tempfile.TemporaryDirectory() as temp_dir:
-            temp_dir = Path(temp_dir)
-            monitor_target = JsonContentMonitorTarget(target=temp_dir / "test.json", node_path=["key1", "key2"])
+            target_file = Path(temp_dir) / "test.json"
+            monitor_target = JsonContentMonitorTarget(target=target_file, node_path=["key1", "key2"])
 
             assert monitor_target.update_cache(cache) is True, "first time"
             assert monitor_target.update_cache(cache) is False, "still not exist"
@@ -94,23 +99,23 @@ def test_content_modification_monitor_target(self):
                     "key1": "value1",
                 }
             }
-            (temp_dir / "test.json").write_text(json.dumps(data))
+            write_json(target_file, data)
             assert monitor_target.update_cache(cache) is False, "no related content found"
 
             data["key1"]["key2"] = "value2"
-            (temp_dir / "test.json").write_text(json.dumps(data))
+            write_json(target_file, data)
             assert monitor_target.update_cache(cache) is True, "new content"
 
             data["key1"]["key2"] = "value3"
-            (temp_dir / "test.json").write_text(json.dumps(data))
+            write_json(target_file, data)
             assert monitor_target.update_cache(cache) is True, "change related"
 
             data["key1"]["key1"] = "value2"
-            (temp_dir / "test.json").write_text(json.dumps(data))
+            write_json(target_file, data)
             assert monitor_target.update_cache(cache) is False, "change not related"
 
             del data["key1"]["key2"]
-            (temp_dir / "test.json").write_text(json.dumps(data))
+            write_json(target_file, data)
             assert monitor_target.update_cache(cache) is True, "delete related"
 
     def test_monitor(self, capsys):
@@ -125,7 +130,7 @@ def test_monitor(self, capsys):
 
             try:
                 # give monitor some time to start
-                time.sleep(0.2)
+                time.sleep(0.1)
                 stdout, _ = capsys.readouterr()
                 assert stdout == "callback\n", "callback for first run"
 
@@ -181,7 +186,7 @@ def callback_accept_last_result(last_result, *, step):
             future = executor.submit(monitor.start_monitor, interval=0.05)
             try:
                 # give monitor some time to start
-                time.sleep(0.2)
+                time.sleep(0.1)
                 assert global_var_2 == 0, "callback for first run"
 
                 global_var = 1

src/promptflow-devkit/tests/sdk_cli_test/unittests/test_utils.py

@@ -373,7 +373,7 @@ def test_resolve_flow_language(self):
 
         with pytest.raises(UserErrorException) as ex:
             resolve_flow_language(flow_path="mock_path")
-        assert "must exist and of suffix yaml, yml or prompty." in ex.value.message
+        assert "mock_path does not exist." in ex.value.message
 
 
 @pytest.mark.unittest