Press again for the tab the driver lost, not the one Chromium never made

tests/CLAUDE.md

@@ -280,6 +280,13 @@ If a race appears only on a loaded machine, make the ordering explicit with
 the route before the gesture whose request it must catch. For initial navigation,
 attach it through `primed` so no request is already in flight.
 
+That rule is about the page. A fact the driver loses on its way out of the browser
+is not a page state any route can arrange, and it has no second channel to be read
+through: `opened_tab` makes the press again because Chromium made the tab every time
+and Playwright reported none of the lost ones. Reach for a repeat only with that
+evidence in hand — the browser's own record showing the subject did its part — and
+say so where the repeat is written.
+
 A handler that appends a route to `held` has established only that the browser made
 the request. Before indexing `held`, wait for the corresponding `Traffic` edge, a
 request event, or another fact named by the handler. Some resources are requested

tests/render_harness.py

@@ -908,6 +908,56 @@ def open_page(
     return page, errors
 
 
+def opened_tab(page, press, tries=3, each=10_000):
+    """The tab a press opens, pressed again when the harness loses the one Chromium made.
+
+    Chromium makes the tab every time. After a press whose tab never arrives,
+    `Target.getTargets` holds a second page target in this browser context — attached,
+    loaded, titled, sitting at the href the press named — while `context.pages` still
+    holds one, and it stays that way for the life of the page: the targets pile up press
+    after press and Playwright reports none of them. So `expect_page` spends its whole
+    timeout waiting on a tab that already exists, and the test reads as though the press
+    had opened nothing.
+
+    A driver that loses the handle is not a page state a route can arrange, and there is
+    no second channel to reach an unreported tab through, so the press is made again
+    rather than waited on longer. This is instrument repair, not tolerance for a flaky
+    subject: the press itself is deterministic — the loss reaches every chord, though not
+    at one rate: 3, 10 and 1 of 60 presses lost for ⌃-click, ⌃⇧-click and ⇧-click on a
+    loaded machine — so a runtime that stopped leaving a real href for the platform to act
+    on opens no tab for any of the tries, and the last one says which wait went unanswered.
+
+    A press whose tab is lost still leaves that tab loaded and polling its server, and no
+    caller can close what it was never handed. A test that closes the tab it receives is
+    closing only the try that was reported; the rest stand until context teardown. That is
+    the standing cost of the repeat, not a leak to chase.
+
+    A press that refuses outright — an anchor hidden, covered, or disabled, the shape a
+    runtime regression takes — raises its own timeout from inside the wait, and Playwright's
+    `EventContextManager.__exit__` cancels the wait and lets it through. Repeating that
+    press would be exactly the tolerance this helper is not, so it is caught where it is
+    raised and named as the subject's refusal.
+    """
+    for attempt in range(tries):
+        try:
+            with page.context.expect_page(timeout=each) as opened:
+                try:
+                    press()
+                except PlaywrightTimeout as refused:
+                    raise AssertionError(
+                        "the press timed out before any tab could open: the subject "
+                        "refused the gesture, which is not the loss this repeats for"
+                    ) from refused
+            return opened.value
+        except PlaywrightTimeout as lost:
+            if attempt == tries - 1:
+                raise AssertionError(
+                    f"no tab after {tries} presses waiting {each}ms each: either the "
+                    "press stopped leaving a real href, or Chromium holds a target "
+                    "Playwright never reported"
+                ) from lost
+
+
 def primed(browser, prepare):
     """A browser whose pages reach the product with the suite's hands already on them.
 

tests/render_support.py

@@ -276,6 +276,7 @@
     leaf_page,
     navigate,
     open_page,
+    opened_tab,
     page_registry,
     panel_settled,
     post_event,
@@ -537,6 +538,7 @@
     "navigate",
     "one_reader",
     "open_page",
+    "opened_tab",
     "other_leaf",
     "page_at_rest",
     "page_registry",

tests/test_render_controls.py

@@ -78,6 +78,7 @@
     live_watcher,
     mark_edges,
     open_page,
+    opened_tab,
     page_at_rest,
     page_registry,
     panel_settled,
@@ -1768,12 +1769,11 @@ def test_the_banner_opens_a_panel_of_the_machines_leaves(
         f"The other leaf\n{tmp_path / 'other-work'}\nWorking — running the suite",
     )
     destination = link.get_attribute("href")
-    with page.context.expect_page() as opened:
-        link.click()
+    tab = opened_tab(page, link.click)
     # The new tab keeps the other page's live root, authorized by the key its link
     # carried, rather than being redirected onto one immutable version.
     assert destination is not None and destination.startswith(f"{other_url}/?t=")
-    expect(opened.value).to_have_url(destination)
+    expect(tab).to_have_url(destination)
     # The press left this tab alone, tray still standing.
     expect(others_panel).to_be_visible()
     page.keyboard.press("Escape")
@@ -1943,10 +1943,9 @@ def test_the_leaves_tray_takes_the_keyboard(browser, serve, live_leaf):
     # Enter is the browser's own on a link, which is why the row is one.
     page.keyboard.press("ArrowDown")
     destination = rows.nth(1).get_attribute("href")
-    with page.context.expect_page() as opened:
-        page.keyboard.press("Enter")
+    tab = opened_tab(page, lambda: page.keyboard.press("Enter"))
     assert destination is not None and destination.startswith(f"{other_url}/?t=")
-    expect(opened.value).to_have_url(destination)
+    expect(tab).to_have_url(destination)
     page.keyboard.press("Escape")
     expect(page.locator(".lf-others-panel")).not_to_be_visible()
     # Closing while focus is inside would drop the reader on the body; it lands on

tests/test_render_projection.py

@@ -51,6 +51,7 @@
     leaf_page,
     live_url,
     open_page,
+    opened_tab,
     page_registry,
     painted,
     panel_settled,
@@ -2354,9 +2355,7 @@ def test_a_message_reference_travels_or_says_it_cant(browser, serve):
     # holds — ⌘ where it was written, ⌃ where CI runs it — so the press names the
     # gesture and lets Playwright spell it. Named outright, the Linux press opened
     # nothing at all and the wait for the tab ran its full 30s before saying so.
-    with page.context.expect_page() as opened:
-        live.click(modifiers=["ControlOrMeta"])
-    tab = opened.value
+    tab = opened_tab(page, lambda: live.click(modifiers=["ControlOrMeta"]))
     tab.wait_for_function(BOTH_STAMPS)
     tab.wait_for_function(
         """() => { const r = document.getElementById('p-bath').getBoundingClientRect();