Python: [BREAKING] preserve expression results in SendActivity output

python/packages/declarative/agent_framework_declarative/_workflows/_executors_basic.py

@@ -224,6 +224,13 @@ class SendActivityExecutor(DeclarativeActionExecutor):
     """Executor for the SendActivity action.
 
     Sends a text message or activity as workflow output.
+    Authored text starting with ``=`` is evaluated and its result is emitted as data.
+    Other authored text supports ``{Variable.Path}`` template interpolation.
+
+    Expression results are not interpolated again. To migrate text that relied on
+    a second pass, author the template directly (``Hello, {Local.name}!``) or build
+    the final text in the expression (``="Hello, " & Local.name & "!"``).
+    Both forms work as a string activity or as a mapping's ``text`` field.
     """
 
     @handler
@@ -244,11 +251,7 @@ async def handle_action(
             text = activity
 
         if isinstance(text, str):
-            # First evaluate any =expression syntax
-            text = state.eval_if_expression(text)
-            # Then interpolate any {Variable.Path} template syntax
-            if isinstance(text, str):
-                text = state.interpolate_string(text)
+            text = state.eval_if_expression(text) if text.startswith("=") else state.interpolate_string(text)
 
         # Yield the text as workflow output
         if text:

python/packages/declarative/tests/test_graph_coverage.py

@@ -556,8 +556,20 @@ async def test_clear_all_variables_executor(self, mock_context, mock_state):
         assert state.get("Local.a") is None
         assert state.get("Local.b") is None
 
-    async def test_send_activity_with_dict_activity(self, mock_context, mock_state):
-        """Test SendActivityExecutor with dict activity containing text field."""
+    @_requires_powerfx
+    @pytest.mark.parametrize(
+        "activity",
+        [
+            "Hello, {Local.name}!",
+            {"text": "Hello, {Local.name}!"},
+            '="Hello, " & Local.name & "!"',
+            {"text": '="Hello, " & Local.name & "!"'},
+        ],
+    )
+    async def test_send_activity_with_authored_greeting(
+        self, mock_context: MagicMock, mock_state: MagicMock, activity: str | dict[str, str]
+    ) -> None:
+        """Authored templates and explicit expressions support the same greeting."""
         from agent_framework_declarative._workflows._executors_basic import (
             SendActivityExecutor,
         )
@@ -568,12 +580,12 @@ async def test_send_activity_with_dict_activity(self, mock_context, mock_state):
 
         action_def = {
             "kind": "SendActivity",
-            "activity": {"text": "Hello, {Local.name}!"},
+            "activity": activity,
         }
         executor = SendActivityExecutor(action_def)
         await executor.handle_action(ActionTrigger(), mock_context)
 
-        mock_context.yield_output.assert_called_once_with("Hello, Alice!")
+        mock_context.yield_output.assert_awaited_once_with("Hello, Alice!")
 
     async def test_send_activity_with_string_activity(self, mock_context, mock_state):
         """Test SendActivityExecutor with string activity."""
@@ -613,6 +625,27 @@ async def test_send_activity_with_expression(self, mock_context, mock_state):
 
         mock_context.yield_output.assert_called_once_with("Dynamic message")
 
+    @_requires_powerfx
+    @pytest.mark.parametrize("activity", ["=Local.msg", {"text": "=Local.msg"}])
+    async def test_send_activity_preserves_expression_result(
+        self, mock_context: MagicMock, mock_state: MagicMock, activity: str | dict[str, str]
+    ) -> None:
+        """Expression results are output data, not authored templates."""
+        from agent_framework_declarative._workflows._executors_basic import (
+            SendActivityExecutor,
+        )
+
+        state = DeclarativeWorkflowState(mock_state)
+        state.initialize()
+        message = "Keep {Local.marker} as text."
+        state.set("Local.msg", message)
+        state.set("Local.marker", "fixture value")
+
+        executor = SendActivityExecutor({"kind": "SendActivity", "activity": activity})
+        await executor.handle_action(ActionTrigger(), mock_context)
+
+        mock_context.yield_output.assert_awaited_once_with(message)
+
 
 # ---------------------------------------------------------------------------
 # Agent Executors Tests - Covering _executors_agents.py gaps