Fix trigger value regression with st.rerun (#7643)

lib/streamlit/runtime/scriptrunner/script_runner.py

@@ -536,7 +536,11 @@ def _run_script(self, rerun_data: RerunData) -> None:
                 self._session_state[SCRIPT_RUN_WITHOUT_ERRORS_KEY] = True
         except RerunException as e:
             rerun_exception_data = e.rerun_data
-            premature_stop = True
+            # Interruption due to a rerun is usually from `st.rerun()`, which
+            # we want to count as a script completion so triggers reset.
+            # It is also possible for this to happen if fast reruns is off,
+            # but this is very rare.
+            premature_stop = False
 
         except StopException:
             # This is thrown when the script executes `st.stop()`.

lib/streamlit/runtime/state/session_state.py

@@ -534,6 +534,7 @@ def on_script_finished(self, widget_ids_this_run: set[str]) -> None:
             run. Any widget state whose ID does *not* appear in this set
             is considered "stale" and will be removed.
         """
+        self._reset_triggers()
         self._remove_stale_widgets(widget_ids_this_run)
 
     def _reset_triggers(self) -> None:

lib/streamlit/testing/v1/app_test.py

@@ -80,7 +80,6 @@
     WidgetList,
 )
 from streamlit.testing.v1.local_script_runner import LocalScriptRunner
-from streamlit.testing.v1.util import patch_config_options
 from streamlit.util import HASHLIB_KWARGS
 from streamlit.web.bootstrap import _fix_matplotlib_crash
 
@@ -302,13 +301,12 @@ def _run(
             new_secrets._secrets = self.secrets
             st.secrets = new_secrets
 
-        with patch_config_options({"runner.postScriptGC": False}):
-            script_runner = LocalScriptRunner(self._script_path, self.session_state)
-            self._tree = script_runner.run(widget_state, self.query_params, timeout)
-            self._tree._runner = self
-            # Last event is SHUTDOWN, so the corresponding data includes query string
-            query_string = script_runner.event_data[-1]["client_state"].query_string
-            self.query_params = parse.parse_qs(query_string)
+        script_runner = LocalScriptRunner(self._script_path, self.session_state)
+        self._tree = script_runner.run(widget_state, self.query_params, timeout)
+        self._tree._runner = self
+        # Last event is SHUTDOWN, so the corresponding data includes query string
+        query_string = script_runner.event_data[-1]["client_state"].query_string
+        self.query_params = parse.parse_qs(query_string)
 
         # teardown
         with source_util._pages_cache_lock:

lib/streamlit/testing/v1/local_script_runner.py

@@ -18,12 +18,14 @@
 from typing import Any
 from urllib import parse
 
+from streamlit import runtime
 from streamlit.proto.ForwardMsg_pb2 import ForwardMsg
 from streamlit.proto.WidgetStates_pb2 import WidgetStates
 from streamlit.runtime.forward_msg_queue import ForwardMsgQueue
 from streamlit.runtime.memory_uploaded_file_manager import MemoryUploadedFileManager
 from streamlit.runtime.scriptrunner import RerunData, ScriptRunner, ScriptRunnerEvent
 from streamlit.runtime.scriptrunner.script_cache import ScriptCache
+from streamlit.runtime.scriptrunner.script_run_context import ScriptRunContext
 from streamlit.runtime.state.safe_session_state import SafeSessionState
 from streamlit.testing.v1.element_tree import ElementTree, parse_tree_from_messages
 
@@ -121,6 +123,22 @@ def script_stopped(self) -> bool:
                 return True
         return False
 
+    def _on_script_finished(
+        self, ctx: ScriptRunContext, event: ScriptRunnerEvent, premature_stop: bool
+    ) -> None:
+        # Only call `_remove_stale_widgets`, so that the state of triggers is still
+        # visible in the element tree.
+        if not premature_stop:
+            self._session_state._state._remove_stale_widgets(ctx.widget_ids_this_run)
+
+        # Signal that the script has finished. (We use SCRIPT_STOPPED_WITH_SUCCESS
+        # even if we were stopped with an exception.)
+        self.on_event.send(self, event=event)
+
+        # Remove orphaned files now that the script has run and files in use
+        # are marked as active.
+        runtime.get_instance().media_file_mgr.remove_orphaned_files()
+
 
 def require_widgets_deltas(runner: LocalScriptRunner, timeout: float = 3) -> None:
     """Wait for the given ScriptRunner to emit a completion event. If the timeout

lib/tests/streamlit/runtime/scriptrunner/script_runner_test.py

@@ -588,13 +588,14 @@ def test_widgets(self):
                 scriptrunner, ["True", "matey!", "2", "True", "loop_forever"]
             )
 
-            # Rerun with previous values. Everything should be the same.
+            # Rerun with previous values. The button should be reset;
+            # everything else should be the same.
             scriptrunner.clear_forward_msgs()
             scriptrunner.request_rerun(RerunData())
 
             require_widgets_deltas([scriptrunner])
             self._assert_text_deltas(
-                scriptrunner, ["True", "matey!", "2", "True", "loop_forever"]
+                scriptrunner, ["True", "matey!", "2", "False", "loop_forever"]
             )
 
         finally: