test: Update test to use variable, not capture stdout (#1236)

Author: karangattu

tests/playwright/shiny/session/flush/app.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import asyncio
+from typing import List
 
 from shiny import App, Inputs, Outputs, Session, reactive, render, ui
 
@@ -37,8 +38,10 @@
     ui.output_text_verbatim("all_txt", placeholder=True),
     ui.tags.span("Flush events: "),
     ui.output_text_verbatim("flush_txt", placeholder=True),
-    ui.tags.span("Flushed: "),
+    ui.tags.span("Flushed events: "),
     ui.output_text_verbatim("flushed_txt", placeholder=True),
+    ui.tags.span("Session end events (refresh App to add events): "),
+    ui.output_text_verbatim("session_end_txt", placeholder=True),
     ui.tags.script(
         """
         $(document).on('shiny:connected', function(event) {
@@ -55,18 +58,20 @@
     ),
 )
 
+session_ended_messages: List[str] = []
+
 
 def server(input: Inputs, output: Outputs, session: Session):
     def on_ended_sync(txt: str):
         def _():
-            print(txt)
+            session_ended_messages.append(txt)
 
         return _
 
     def on_ended_async(txt: str):
         async def _():
             await asyncio.sleep(0)
-            print(txt)
+            session_ended_messages.append(txt)
 
         return _
 
@@ -181,5 +186,9 @@ def flush_txt():
     def flushed_txt():
         return str(flushed_vals.get())
 
+    @render.text
+    def session_end_txt():
+        return str(session_ended_messages)
+
 
 app = App(app_ui, server)

tests/playwright/shiny/session/flush/test_on_flush.py

@@ -1,26 +1,10 @@
-import os
-
-import pytest
 from conftest import ShinyAppProc
 from controls import OutputTextVerbatim
 from playwright.sync_api import Page
 
-on_ci = os.environ.get("CI", "False") == "true"
-
 
 def test_output_image_kitchen(page: Page, local_app: ShinyAppProc) -> None:
 
-    if on_ci:
-        # 2024-03-22: The tests pass locally, but do not pass on CI. It started with
-        # https://github.com/posit-dev/py-shiny/commit/2f75a9076c567690f2a6a647ec07cfa9e558ff9c
-        # , but the changes in that commit were unrelated. We had believe it was an
-        # update in uvicorn, but removing all other debug statements did not fix the
-        # issue.
-        # 2024-03-22 Barret: When inspecting the issue, we found that many log
-        # INFO entries have different port values. This is concerning.
-        # https://github.com/posit-dev/py-shiny/pull/1236
-        pytest.skip("Error with stdout / stderr on CI. Related #1236")
-
     page.goto(local_app.url)
 
     OutputTextVerbatim(page, "all_txt").expect_value(
@@ -37,23 +21,10 @@ def test_output_image_kitchen(page: Page, local_app: ShinyAppProc) -> None:
         "('a-3-flushed', 'bx-3-first-flushed', 'by-3-first-flushed', "
         "'bx-3-second-flushed', 'by-3-second-flushed', 'c-3-flushed')"
     )
-
-    # Verify `on_ended` callbacks are called in the correct order (and cancelled)
-    local_app.close()
-
-    # Wait up to 3 seconds for the app to close and print the logs. (Should be ~ instant)
-    local_app.stdout.wait_for(lambda x: "test4" in x, 3)
-    stdout = str(local_app.stdout)
-    out_indexes = [
-        stdout.index("session ended - sync - test1"),
-        stdout.index("session ended - async - test2"),
-        stdout.index("session ended - async - test3"),
-        stdout.index("session ended - sync - test4"),
-    ]
-    for i in range(len(out_indexes)):
-        index = out_indexes[i]
-        assert index >= 0
-        # Make sure they are ordered correctly
-        if i > 0:
-            prev_index = out_indexes[i - 1]
-            assert index > prev_index
+    # Session end messages have not flushed yet
+    OutputTextVerbatim(page, "session_end_txt").expect_value("[]")
+    page.reload()
+    # Session end messages have flushed
+    OutputTextVerbatim(page, "session_end_txt").expect_value(
+        "['session ended - sync - test1', 'session ended - async - test2', 'session ended - async - test3', 'session ended - sync - test4']"
+    )